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Other Discussions => Off-Topic => Topic started by: ToyMachine78 on 05/28/2016, 02:21 PM

Title: Tire Question
Post by: ToyMachine78 on 05/28/2016, 02:21 PM
Anyone know why my car dealership sets my tire pressure 2 psi lower on the left side than the right?

When I bought my truck the pressure was 34 right/32 left. After having it serviced today which included tire servicing, it's 36 right/34 left.

I've always set all my tires to the same pressure.
Title: Re: Tire Question
Post by: thesteve on 05/28/2016, 03:18 PM
no thats just bizarre
you should have a front and back spec, but left right should be balanced
Title: Re: Tire Question
Post by: jperryss on 05/28/2016, 05:55 PM
They figured it'll be perfect once you're sitting in the car driving it?

Since they all went up by 2PSI, my guess is they didn't actually check the pressure and just decided each tire needed a little air.
Title: Re: Tire Question
Post by: crazydean on 05/28/2016, 07:42 PM
Sounds like a case of "good enough".

Pro Tip: Always check your tire pressure BEFORE driving the car. The temperature inside the tires will increase from friction created by the tires rolling along the road. This increased temp will result in increased pressure inside your tire. Recommended tire pressure is always cold.
Title: Re: Tire Question
Post by: SignOfZeta on 05/28/2016, 08:42 PM
Because they don't care.
Title: Re: Tire Question
Post by: NightWolve on 05/28/2016, 09:50 PM
In an age of digital pressure testers (I keep one in my car's repurposed ash tray), they should be better about it...
Title: Re: Tire Question
Post by: ToyMachine78 on 05/28/2016, 10:44 PM
Well my trucks display shows the pressure of each tire, so it's too exact to be an i don't care scenario, or just add a little air to each one. 
Title: Re: Tire Question
Post by: SignOfZeta on 05/29/2016, 12:04 AM
I suppose its possible that they are setting the pressure in a service bay where there is an air line on each side and the gauge on one side is 2psi off from the other.

Are *you* using a gauge or are you relying on TPMS data from the CAN bus? I ask because those things aren't always accurate. Just because you see a number that indicates tolerance to .1 PSI doesn't mean its actually capable of measuring that accurately.
Title: Re: Tire Question
Post by: DeshDildo on 05/29/2016, 12:18 AM
Quote from: SignOfZeta on 05/29/2016, 12:04 AMI suppose its possible that they are setting the pressure in a service bay where there is an air line on each side and the gauge on one side is 2psi off from the other.

Are *you* using a gauge or are you relying on TPMS data from the CAN bus? I ask because those things aren't always accurate. Just because you see a number that indicates tolerance to .1 PSI doesn't mean its actually capable of measuring that accurately.
This!  TPMS readout is not always perfectly accurate.  Let us no if the actual pressures are off.  When I used to work at a dealer people used to freak out about it.  Even if we set pressures correctly if the dash didn't match they would lose their minds.  So we'd make the dash readout correct which in turn made the actual tire pressures in correct to appease the ignorant.
Title: Re: Tire Question
Post by: ToyMachine78 on 05/29/2016, 09:03 AM
Quote from: SignOfZeta on 05/29/2016, 12:04 AMI suppose its possible that they are setting the pressure in a service bay where there is an air line on each side and the gauge on one side is 2psi off from the other.

Are *you* using a gauge or are you relying on TPMS data from the CAN bus? I ask because those things aren't always accurate. Just because you see a number that indicates tolerance to .1 PSI doesn't mean its actually capable of measuring that accurately.
No I haven't verified manually. I'll check and report the results.
Title: Re: Tire Question
Post by: BlueBMW on 05/29/2016, 10:40 AM
Hence why I was so glad that BMW opted to not show numerical tire pressures.  They just did green, yellow or red.  Tire pressure lights were pain enough without customers nit picking over numerical variations.

Then they had to go and do this fancy detailed oil level gauge thingy... Customers would come in "my car is low on oil" I check it and its 1 notch below full on the display meaning its maybe 0.1 quarts lower than max.  But they wanted it fixed lol.

So glad I dont work as a tech anymore.
Title: Re: Tire Question
Post by: wildfruit on 05/29/2016, 04:33 PM
That's odd. My BMW shows the colours for each tyre and a number figure for each in either bar psi or Kpa. But the oil doesn't have a gauge just "ok" or top up. Also it doesn't have a dip stick. I hate that.
Title: Re: Tire Question
Post by: SignOfZeta on 05/29/2016, 05:21 PM
I appreciate TPMS and I'm glad it's on every car now. However I don't see any reason to know your tire temps and pressures in real time. A failure light is all you need, one of them even. Even in a motorsports situation where that info is super valuable the driver doesn't look at it when he's hauling ass, the team analyzes it via telemetry and/or its studied later. My track car only has speed, water temp, oil pressure, RPM, fuel level, and lambda and I don't have time to check those, even in a slow-ass Miata. An F1 driver never looks at anything unless he's changing a setting with only the last %10 of the RPM being visible without menu diving.

Most manufacturers have switched to a wheel speed based equation to determine if deflation has occurred and I'm glad. Now we can go back to running regualar wheels again and TPMS is essentially free.
Title: Re: Tire Question
Post by: ToyMachine78 on 05/29/2016, 08:03 PM
Well measured them manually and the truck readings were spot on, so I just adjusted them all to 34psi
Title: Re: Tire Question
Post by: SignOfZeta on 05/29/2016, 09:27 PM
Weird.
Title: Re: Tire Question
Post by: BlueBMW on 05/30/2016, 02:24 PM
Quote from: wildfruit on 05/29/2016, 04:33 PMThat's odd. My BMW shows the colours for each tyre and a number figure for each in either bar psi or Kpa. But the oil doesn't have a gauge just "ok" or top up. Also it doesn't have a dip stick. I hate that.
Must be the newer ones that do that.  Bummer for the BMW techs :(
Title: Re: Tire Question
Post by: SignOfZeta on 05/30/2016, 04:27 PM
The original Miata had an actual analog oil pressure gauge. It was eventually replaced a few years later with a switch based one, fake basically, just a gauge that looks like a gauge but does the same thing as a light. Right around the same time GM made the same change with their light trucks.

Customers who think they are informed are a constant source of irritation. If you give some people a tiny amount of data all they can do is find imaginary problems with it.
Title: Re: Tire Question
Post by: TDIRunner on 05/31/2016, 09:45 AM
I've seen many vehicles that require different pressures in the front vs. the rear, but never between the right side and the left side.  As others have said, I would check them manually just to verify it isn't the TPMS.  I would also make sure you check the tires when they are cold.  I've actually seen situations where a car is sitting outside with the sun beating on one side, and the other side sitting in the shade.  I checked the tire pressure and sure enough, the side sitting in the sun was higher than the other side.  I didn't change the air pressures since I assumed that if everything was the same temperature, the pressures probably would have matched.

I don't mind the idea of the TPMS, but at the end of the day, I still prefer to check them myself.  I recently bought a new van for my wife and it's the first vehicle I've ever owned with a TPMS.  It has the type I prefer, in that it only warns you if one of the tires is low, but it doesn't have the ability to tell you which one.  I also doesn't have anything inside any of the tires themselves, so I don't have to pay extra any time I buy new tires.
Title: Re: Tire Question
Post by: xcrement5x on 05/31/2016, 11:50 AM
Quote from: SignOfZeta on 05/30/2016, 04:27 PMThe original Miata had an actual analog oil pressure gauge. It was eventually replaced a few years later with a switch based one, fake basically, just a gauge that looks like a gauge but does the same thing as a light. Right around the same time GM made the same change with their light trucks.

Customers who think they are informed are a constant source of irritation. If you give some people a tiny amount of data all they can do is find imaginary problems with it.
Lol, I am like this to a fault.  I'm even worse with medical stuff, every time I get bloodwork done I go over every tiny part just to bring it up with my doctor and have him be like "yeah, nothing really to worry about though, you're still within tolerances."
Title: Re: Tire Question
Post by: BlueBMW on 06/01/2016, 06:34 PM
The 1970 mercedes roadster I had several years ago had an oil pressure gauge that had an actual oil line running to it.  So you had a line of hot engine oil behind the gauge cluster at all times.  Kind of concerning I suppose...
Title: Re: Tire Question
Post by: DeshDildo on 06/01/2016, 06:49 PM
Quote from: TDIRunner on 05/31/2016, 09:45 AMI've seen many vehicles that require different pressures in the front vs. the rear, but never between the right side and the left side.  As others have said, I would check them manually just to verify it isn't the TPMS.  I would also make sure you check the tires when they are cold.  I've actually seen situations where a car is sitting outside with the sun beating on one side, and the other side sitting in the shade.  I checked the tire pressure and sure enough, the side sitting in the sun was higher than the other side.  I didn't change the air pressures since I assumed that if everything was the same temperature, the pressures probably would have matched.

I don't mind the idea of the TPMS, but at the end of the day, I still prefer to check them myself.  I recently bought a new van for my wife and it's the first vehicle I've ever owned with a TPMS.  It has the type I prefer, in that it only warns you if one of the tires is low, but it doesn't have the ability to tell you which one.  I also doesn't have anything inside any of the tires themselves, so I don't have to pay extra any time I buy new tires.
TPMS is aggravating to me.  A cost passed on to the consumer thanks to federal law.  A law enacted mainly after the Ford/Firestone fiasco (which TPMS wouldn't have really made a difference) as well as people not checking their own tires, having a blowout, and causing a wreck  Makes total sense to go through all that because people are to lazy, negligent, ignorant to check tire pressures.  Basic mechanical ability like checking tires, oil level, etc. NEEDS to be taught as part of driver's ed.
Title: Re: Tire Question
Post by: SignOfZeta on 06/01/2016, 08:27 PM
Yeah, but it isn't and it's not on the books to ever take place. Anyone can see this. So in that situation do you just let people die or do you do something about it?

The list of federally mandated safety features on American cars is so huge that TMPS is barely noticeable. Furthermore it's actually useful. Maybe you are so vigilant you check your pressures every time you get in the car, but the causes of tire deflation generally take place with the car IN MOTION so unless you have superpowers TPMS is the only way to know it's happening when it's happening.

And you're right, it wouldn't have helped the Firestone Ford Explorer problem because those were terrible drivers in a terrible car. Nothing could save those people. However, I went over a nasty pot hole last year and when the light came on it wasn't hard to put 2 and 2 together. I'm a master automobile mechanic with an almost perfect driving record on and off the track who can totally rebuilt all four of my cars from the ground up and I find TPMS useful. I think resistance is due more to ego than anything, honestly. The same people complained about pretty much every advance in auto technology since Unsafe at Any Speed. Collapsible steering columns, EGR, exhaust catylizers, seat belts, safety glass, unitized construction, fuel injection, 3rd brake lights, ABS, airbags, synthetic oil, crash bars, crumple zones, etc etc. the end result is that cars are many times safer than they used to be and only need maintenance annually, and now most of the time even shitty cars like Chryslers can run a quarter million miles without problems. Every car sold today puts less hydrocarbon out its exhaust than what exists in the air naturally. Fuel economy per pound is WAY up. Adjusted for inflation cars don't cost any more than they did 35 years ago and mechanics make way less.

The "cost" of TPMS was minimal at introduction and now with wheel speed based systems it's actually free. I think TPMS is fucking great and the only reason there wasn't a light for it 60 years ago is because the tech wasn't there. If it were, we'd be used to it. 

If you're getting a raw deal in relation to your car it's honestly coming from your bank, your insurance company, or the cops. The OEMs are packing maximum value as long as you don't buy something stupid like a Jeep Compass or an X6M.
Title: Re: Tire Question
Post by: DeshDildo on 06/01/2016, 09:22 PM
Quote from: SignOfZeta on 06/01/2016, 08:27 PMYeah, but it isn't and it's not on the books to ever take place. Anyone can see this. So in that situation do you just let people die or do you do something about it?

The list of federally mandated safety features on American cars is so huge that TMPS is barely noticeable. Furthermore it's actually useful. Maybe you are so vigilant you check your pressures every time you get in the car, but the causes of tire deflation generally take place with the car IN MOTION so unless you have superpowers TPMS is the only way to know it's happening when it's happening.

And you're right, it wouldn't have helped the Firestone Ford Explorer problem because those were terrible drivers in a terrible car. Nothing could save those people. However, I went over a nasty pot hole last year and when the light came on it wasn't hard to put 2 and 2 together. I'm a master automobile mechanic with an almost perfect driving record on and off the track who can totally rebuilt all four of my cars from the ground up and I find TPMS useful. I think resistance is due more to ego than anything, honestly. The same people complained about pretty much every advance in auto technology since Unsafe at Any Speed. Collapsible steering columns, EGR, exhaust catylizers, seat belts, safety glass, unitized construction, fuel injection, 3rd brake lights, ABS, airbags, synthetic oil, crash bars, crumple zones, etc etc. the end result is that cars are many times safer than they used to be and only need maintenance annually, and now most of the time even shitty cars like Chryslers can run a quarter million miles without problems. Every car sold today puts less hydrocarbon out its exhaust than what exists in the air naturally. Fuel economy per pound is WAY up. Adjusted for inflation cars don't cost any more than they did 35 years ago and mechanics make way less.

The "cost" of TPMS was minimal at introduction and now with wheel speed based systems it's actually free. I think TPMS is fucking great and the only reason there wasn't a light for it 60 years ago is because the tech wasn't there. If it were, we'd be used to it. 

If you're getting a raw deal in relation to your car it's honestly coming from your bank, your insurance company, or the cops. The OEMs are packing maximum value as long as you don't buy something stupid like a Jeep Compass or an X6M.
If I'm not mistaken indirect TPMS (Wheel speed monitored) does not meet federal law after 07' model year requiring the use of direct sensors.  This IS additional cost that doesn't need to be there.  Sensors, receiver, additional wiring and changes to body control modules are all production and development cost.  They also are a nice little $100 plus replacement to the consumer when one goes bad.

This isn't much different than when electronic stability control and traction control became a federal mandate in 09ish?  Some vehicles I was happy to have it, others not so much.  Those electronics got me stuck in the snow in my Chevy Express work van plenty of times.  Aggravation! 

So cars are the same cost as years past adjusted for inflation.  So what?  You wouldn't like the choice of possibly a cheaper alternative?

Maybe I'm old school but I check tire pressure every time I fill with fuel.  I also check tire pressure anytime there's a large temperature swing in the weather. 

Yes, I have gotten flat tires while driving, it's not hard to figure out when there is a noise or the car is handling different that you need to slow down and pull over as soon as it's safe.  I have also hit my fair share of chuck holes and yes, I pull over when it's safe to inspect for damage.  These all seem like common sense items to me.

I just feel like laws are passed everyday that help make society more and more lazy and more and more dependent on electronics.

As far as emissions, I can agree with stipulations set in place there.  Crash testing I can also agree with to some extent.  This again should be a choice and an option that would be a SELLING point in our capitalist system. 

If none of these laws were in place do you really think we'd still be buying Yugos?  Natural sales competition would drive manufacturers to better their product in every way to keep up with competition.  Case in point the now federally mandated crap I was bitching about have been options on cars for decades before they were forced on everyone.

I also was ASE Master certified and spent a decade in the automotive field.  I also raced stock cars for a few years, have run many passes down drag strips and have road course and auto cross experience.  It appears our backgrounds are similar but opinions are different.

P.S. my wife's aunt has a Sebring convertible with a 2.7 and 150k.  It is undoubtedly one of the few 2.7's I've ever seen go over 100k.  Chryslers are shit but, job security when you are an auto mechanic.
Title: Re: Tire Question
Post by: spenoza on 06/01/2016, 09:55 PM
Car prices have inflated faster than general inflation, partially as a result of all the safety mandates, but on the other hand, newer cars actually have much longer lifespans than older cars (there's a good bit of literature out there on that, so don't give me the old "they don't make 'em like they used to" speech"). And the safety systems have reduced accidents and deaths and major injuries from accidents, which saves the public money since our taxes help subsidize hospital emergency care for those who can't afford it. Nothing drains public health funds like having someone with no health insurance in the hospital with a severed spine.

Truth is, I'm relatively certain on one particular drive through the mountains of West Virginia in a massive rain storm the traction control on a rented SUV saved my life several times (the first time was a real surprise, but after that I altered my driving style dramatically and still had a couple more surprise saves). It was bad enough I had to stop for an hour because visibility from the heavy rain had dropped to zilch.
Title: Re: Tire Question
Post by: DeshDildo on 06/01/2016, 10:27 PM
Quote from: guest on 06/01/2016, 09:55 PMCar prices have inflated faster than general inflation, partially as a result of all the safety mandates, but on the other hand, newer cars actually have much longer lifespans than older cars (there's a good bit of literature out there on that, so don't give me the old "they don't make 'em like they used to" speech"). And the safety systems have reduced accidents and deaths and major injuries from accidents, which saves the public money since our taxes help subsidize hospital emergency care for those who can't afford it. Nothing drains public health funds like having someone with no health insurance in the hospital with a severed spine.

Truth is, I'm relatively certain on one particular drive through the mountains of West Virginia in a massive rain storm the traction control on a rented SUV saved my life several times (the first time was a real surprise, but after that I altered my driving style dramatically and still had a couple more surprise saves). It was bad enough I had to stop for an hour because visibility from the heavy rain had dropped to zilch.
Everyone has insurance... Obamacare says so.  If you're too poor to pay for insurance then you get a fine you can't afford.
Title: Re: Tire Question
Post by: SignOfZeta on 06/01/2016, 10:52 PM
The fine for ignoring the ACA is %2 of your income with a max of $975. Way way less than insurance if you're in a pay grade above Medcare/Medicaid. If you are totally destitute making $5000 a year (I've been there, believe me) that's $100 so basically you get $100 less of Earned Income Credit when you do your taxes. It's not exactly a motivator. There are still 35M in the US without insurance. Still zero people in the UK without it. Nothing has changed. Viva America.

As for TMPS, the sensors are either gone or on the way out with most cars. My 2014 Jetta Wagon does not have them and that was the final year of a generation they haven't sold in two years. BMWs probably always will because...that's BMW. The system works for sure too since I've seen the light once on the VW already. My 2013 Fit has sensors. Also ugly ass wheels, one of which is slightly bent. I'm not a fan of the sensors at all but I'll deal with it.

The cool thing about the passive system is that you can switch wheels with anything that fits. You have to press a button in the glove box to tell the ECU to learn the new tire OD.
Title: Re: Tire Question
Post by: Nazi NecroPhile on 06/02/2016, 10:44 AM
If you make $5000 a year you'd be getting a subsidy to cover almost the entire premium, making the insurance (second cheapest silver plan) cost the same as the fine.

As for TPMS, the physical sensors are a bit of a pain and costly, but I don't mind the ones that use the ABS sensors for 'free'.  They've come a long way and work well, unlike the first gen systems that were really only useful for detecting one damaged tire and weren't sophisticated enough to realize that all four tires were under inflated.  Like most safety stuff (abs, traction control, etc.), some implementations will work better than others, but I blame the manufacturer for putting out a shitty system not the gov't.

I'm a bit torn on the backup camera mandate, though.  They're great for seeing behind your mammoth Canyonero, but they're hardly necessary in something like a Corolla or Fit.  Again, it's more of a manufacturer thing, seeing as the cost of the screen and camera (and even nav) is negligible and not the hundreds they try to rape you for.

Title: Re: Tire Question
Post by: TDIRunner on 06/02/2016, 11:55 AM
My 2015 Town & Country does not have sensors in the wheels.  It was an option, but not one that I selected.  The van has the ability to warn my of low tire pressures, but it is going by the wheel speed rather than an actual sensor in the tire, which, like I said earlier, is what I prefer if I have to have some type of TPMS.
Title: Re: Tire Question
Post by: spenoza on 06/02/2016, 08:52 PM
I have fallen in love with the camera. I didn't think I would, but I love it. I can back into parking spaces like a crazed parking parkour expert.
Title: Re: Tire Question
Post by: SignOfZeta on 06/02/2016, 10:42 PM
Quote from: guest on 06/02/2016, 08:52 PMI have fallen in love with the camera. I didn't think I would, but I love it. I can back into parking spaces like a crazed parking parkour expert.
I have a Honda Fit. I can do that anyway.

My coworker's Fit (newer, but made in Mexico like American cars and VWs so I'm not sure what the point is) actually has not one but two cameras. One is in the usual place, one in the right side mirror. It seems pretty dumb from a car that is extremely easy to see out of and has Dumbo ear sized mirrors but then people love to go overboard.

I guess that's the problem with all cars. Cars are designed to appeal to "new car buyers" and those people are at least %90 total moron. People who buy 2WD Honda Ridgelines and complain about fuel economy, etc. The people who have steered BMW away from "The Ultimate Driving Machine" and towards some of the most useless vehicles ever made. People who buy brand new Kias instead of a year old Toyota for the same price. Dodge Caliber owners. Vettes with automatic transmissions. Those jerks.

As for cameras: let me put it this way. Most cars already have a big LCD now for all the Bluetooth stereo bullshit and you can buy a cheap Android burner for $20 so I can't honestly see these cameras increasing the cost of the car. I don't feel the need for one and I don't really enjoy using the one in my Jetta wagon but I will say this: in the vast majority of cars being made today, if a 3 year old kid was sitting on your back bumper and you didn't have a camera you'd never know he was ever there. It's not legally mandated because it makes parking easier, it's there for safety reasons. This doesn't matter to lot of people until it's too late and regret is a motherfucker. If you want to know why suicide is so popular, wait until you smear your neighbors kid halfway down your block and then see how you feel about it yourself.
Title: Re: Tire Question
Post by: DeshDildo on 06/02/2016, 11:09 PM
Quote from: SignOfZeta on 06/02/2016, 10:42 PMI guess that's the problem with all cars. Cars are designed to appeal to "new car buyers" and those people are at least %90 total moron. People who buy 2WD Honda Ridgelines and complain about fuel economy, etc. The people who have steered BMW away from "The Ultimate Driving Machine" and towards some of the most useless vehicles ever made. People who buy brand new Kias instead of a year old Toyota for the same price. Dodge Caliber owners. Vettes with automatic transmissions. Those jerks.
This paragraph is pure gold.
Title: Re: Tire Question
Post by: esteban on 06/03/2016, 07:42 AM
I have enjoyed this thread more than I should have.

And I loathe the topic.
Title: Re: Tire Question
Post by: NightWolve on 06/15/2016, 04:59 AM
I'll admit, I wasn't aware new cars included some form of tire pressure detection. That happens when you've owned the same car for 18 years. ;) It seems counter-intuitive an idea to me to try to stick some kind of say lithium-powered transmitter in the rim between the tire and transmit the data for processing to some control panel display for the driver to see. But I guess it makes sense that it's accomplished by proximity/balance sensors elsewhere though that could never provide exact or even good PSI accuracy as a manual check with a pressure gauge could and is what led to ZeroGamer thinking there was a problem.

Anyway, I had a weird/dangerous experience not that long ago worth pointing out on the subject of the importance of checking your tires from time to time, at least visually! My brakes were going out and I had to keep pumping the pedal to achieve slow down as I was going to a MicroCenter store pretty far away from me in another city!

It was pretty WTF cause I had changed everything myself over the years, the brake lines/pipes, calipers, hoses, drum shoes, drum pistons, etc. and it worked fine for years, so I was pretty upset! The car pretty much runs on mostly AutoZone/AdvanceAuto parts!

So, I stopped the car in a parking lot before getting there, popped the hood and noticed I had full brake fluid which left me not really knowing what the hell was going on (was thinking maybe the booster was finally going bad maybe)...

Well, I got to my destination safely by going slow and pumping the pedal as mentioned, parked, got out and somebody saw my front passenger-side tire was extremely deflated so he pointed it out to me. I was like, "Oh, thanks, f--k, so maybe that's why?!?!" A gas station was across the street, so I refilled it there for some quarters because I didn't have my supply box which had my 12VDC car light/air compressor in it. Sure enough, brakes worked fine again, so WTF ??

I never heard of this behavior due to low tire pressure or practically a flat tire... Never happened again as I try to remember to do visual tire checks, but I don't trust the car like I used to... I'm tired of looking at the rust anyway, so I'll be looking for a new one in the near future and will likely switch to a manual transmission also.
Title: Re: Tire Question
Post by: SignOfZeta on 06/15/2016, 09:24 AM
I think there's more going on there than you're aware of. The only way I can see tire pressure affecting pedal feel is in an ABS event, when the disparate tire pressures confuse the ECU, made worse while turning. Otherwise...I'm pretty sure that's physically impossible.
Title: Re: Tire Question
Post by: wilykat on 06/16/2016, 07:25 PM
Tire pressure sensing is not necessarily just inside tires, some models have different ways of detecting soft tires.  On my Grand Prix, it uses rotation sensors to monitor wheel's rotation rate (part of ABS system) and when the computer detects one of the tire's rotation rate is off by about 25% or more from other tires, it trips low pressure warning.

It can be reset from the dash board such as when you have spare tire (which is smaller and rotates faster on axis) or something.
Title: Re: Tire Question
Post by: SignOfZeta on 06/16/2016, 09:50 PM
Yep. We've covered that at least twice in this thread.
Title: Re: Tire Question
Post by: BlueBMW on 06/22/2016, 07:11 PM
Originally automakers were using "indirect" sensing first.  That involved basically just using the wheel speed sensors of the ABS / traction control system to detect a variation in a specific tire.  If I understand it right though, regulations changed sometime in the mid 2000's to require that new vehicles have "direct" sensors after a certain production date.  I suspect all new cars have direct sensors now which are usually mounted to the valve stem or strapped to the center of the wheel (I think Ford does this).
Title: Re: Tire Question
Post by: SignOfZeta on 06/22/2016, 09:44 PM
No. No no no. Read the thread! :)

The earlier indirect versions were mainly luxery makes looking for a way to help you spend your money. They weren't legally required at all.

When they became the law they went with the systems with sensors.

Now the OEMs have convinced the man that the indirect ones are good enough so newer cars are back to this method.

My 92 Miata has no TMPS.
My 2013 Fit has TPMS sensors.
My 2014 Golf doesn't (virtual).
Title: Re: Tire Question
Post by: BlueBMW on 06/24/2016, 09:52 AM
That is fantastic news then!  I got out of the wrenching business in 2014 so if that's when the changes happened then that's why I missed it.  Direct sensors were always a pain.  They loved to break or lose connection or have their batteries die.  You name it.  Almost every car that came in had a line stating "TPMS light is on"

If they've gone back to indirect detection then that's great.  I wonder if they use indirect on run-flat tires though since they don't deform as much when flat.
Title: Re: Tire Question
Post by: SignOfZeta on 06/24/2016, 01:07 PM
Yeah, you clearly live in BMW world. Run flats are shit to start with and I wouldn't touch them. :)

But you have a point and I wouldn't be surprised, like I said, if BMW and Merc kept at sensors for that reason and others. They don't exactly have a history/ethic of scaling back tech bloat.
Title: Re: Tire Question
Post by: BlueBMW on 06/26/2016, 12:12 AM
It got so technical even I couldn't keep up with it all.  They way over-complicated every aspect of those cars (BMWs that is).  And they wonder why they cant find good technicians anymore.  Its because they've all gone to engineering school instead.
Title: Re: Tire Question
Post by: SignOfZeta on 06/26/2016, 08:34 AM
The deck is so stacked against the American auto technician, heavily favoring crooks. Outside of the very few unionized areas there is no guaranteed pay. They expect you to study all day and spend $2000 a year on tools but generally over-hire to reduce wait times for customers. Making $30 an hour is nice...but not when you stand around all week waiting for work to come in, eventually only banking 20 hours by Friday.

In Germany they have worker protections, four year degrees (which are free), and customers who didn't spend every last cent on their car payment. There the hugely over engineered German car makes sense. In the US it's like trying to get a X Wing fighter tuned up in Hazard County and only being able to find 9 guys to wash your windows.

BTW, I work in an engineering lab these days. You work 40 hours, you get paid 40 hours. If you work 45 the 5 are billed at overtime. You know, like everyone else. If this was more common in dealerships I don't think finding good techs would be hard. Finding good techs is hard because they are constantly changing jobs trying to find one that isn't a total fucking.
Title: Re: Tire Question
Post by: BlueBMW on 07/02/2016, 08:55 PM
Most of the guys I worked with have either gotten out or are trying to get out.  Its interesting in the case of BMW though.  They actually sent out a survey for us asking us why turnover was high.  Overwhelmingly techs described their situation and the high level of dissatisfaction.   BMW's ultimate answer was to ramp up their "STEP" program which is basically an expensive BMW-centric technical school.  Dealers pay $10K and they get a "trained" tech within two weeks.  So rather than try and retain the talent they already had they just turned up the machine to churn out new techs.

Its sad too.  I really feel bad for a lot of these "STEP" students.  They spend a good 20 to 40K doing the school expecting to make 60k to 100k right out the gate.  It never happens that way.  They get to the dealer and maybe make 35K to 40K and most of that goes to buying tools in their first two years.  After two years they realize how fucked up it is and then they're part of the crowd trying to get out.  Oh but wait, they're under a contract with the dealer to work there for three years or they have to pay back the dealer what they spent to get the tech.

Also, many of the STEP students come in thinking they know it all and can do it only to realize they have book knowledge but absolutely no mechanical aptitude.  Quite the shocker when they know how a car works in theory but cant figure out how to use a ratchet effectively.

But you are right.  The crooks are the ones who make it now.  Basically we had two types of technicians: part swappers and true techs.  The true techs were guys like me who could do everything be it diagnosis, rebuild, service, electrical etc.  The part swappers cant diagnose their way out of a paper bag with the bottom cut out of it but they can throw parts in a car super fast.  While they often guess and replace the wrong parts they tend to make the most money.  They turn tons of hours swapping out parts while the other guy is diagnosing some ridiculous electrical problem and barely making the time they're there.  At the end of the week, the crooked part swapper has 80 hours on the books and I have 35.  They make a few bucks less an hour than me but are making double my paycheck.  Add in "performance" bonuses etc and they really rake it in.

Right now I'm working at a laboratory as an engineering intern and the environment is so different is incredible.  I come in and do my job.  I report my own hours and basically manage myself.  The work gets done.
Title: Re: Tire Question
Post by: SignOfZeta on 07/02/2016, 10:15 PM
When I was on vacation in SF once I set up a job interview at a Honda dealership. The guy there explained how the unionized system worked and it sounded pretty good. Basically like any other similar profession, machinist, plumber whatever. "Installer" is actually a title. This is significant because there are actually guys who do the main diagnosis and delegate to the installers. I thought that was a pretty good system since, chances are, you'll have one or two guys that are way better at diagnosis than other guys anyway.

If I had every work order handed to me first and I just did diagnosis and then handed it off to the next guy I could make insane money. The standard hour for diagnosis is usually plenty, especially in a dealership situation where you have full accurate documentation. There are also modifiers for getting more than an hour. I once got paid 11 hours of straight time to diagnose a particularly crazy AC issue since I was going through the whole thing with the technician hotline guys. Similarly if the guy I handed it to did transmission swaps exclusively he could do really well also.

Also he told me that a few months earlier the guys went on strike and shut his shit down for a month. I like that shit a LOT. :) Where I worked the moral was so bad you couldn't even organize a company picnic let alone a picket line.
Title: Tire Question
Post by: esteban on 07/03/2016, 11:16 AM
Picnic @picketline @hotlinebling @neverheardthesong @drake? @honda @tirepressure

:)
Title: Re: Tire Question
Post by: BlueBMW on 07/04/2016, 01:54 PM
That wouldn't be a bad system SoZ.  Some dealerships have formed "diagnosis teams" which are just there to take care of particularly challenging diagnosis problems.  Once they determine what they think needs to be done they give it back to the tech or team where it originated and they perform the fix.  I pushed for these sorts of arrangements for a long time but it was always opposed by the high hour turners.  They didn't want to pay a portion of their hours to support a diagnosis team like that.  Their system of avoiding diag problems and just churning the hours was threatened by such a system.  Management didn't like the idea much either since they were concerned with individual technician productivity numbers.

Sadly some of my most satisfying days as a technician were solving super challenging problems.  Though one car got me really good...

2011 BMW X5 with the twin turbo V8.  Had an intermittent stumble and eventually would post a misfire fault.  I went through EVERYTHING on this car.  By the end we had done the following to it:

Approximate costs shown:
Spark Plugs  $400
All Fuel Injectors (the pricey direct injection units!)  $1600
Both High Pressure Fuel Pumps $1400
All Intake seals $400
All Ignition coils $900
Cylinder compression and leakdown $700
Engine Computer $1400
Software Update / Reprogramming (3 times) $600
Dropped engine and performed carbon cleaning on the valves (You had to drop the engine for this) $2600

All that at it still wasn't fixed.  BMW was stumped, I was stumped.  Finally we pulled the cylinder head on the bank that had the fault.  Sent it off to BMW for analysis.  They sent us a new one back and said the injector bore on the cylinder that was misfiring was out of tolerance.  Apparently when the injector fired it was pushing itself too far back up its bore and then not delivering the fuel correctly at that position.  So basically $10,000 in repairs and then finally needed a cylinder head (a $6800 part plus another $1700 labor)  BMW ended up covering all of it since they couldn't help figure it out until the end.

That twin turbo V8 is easily the hardest BMW engine to work on except maybe the diesel 6 cylinder.  That car broke me.  No one had ever seen that issue before though.  Apparently its becoming common on those engines now.  Though I can say I'm super quick at taking everything apart on that engine now.  I only took the intakes apart maybe 40 times during that diagnosis.  It took us two months to fix it.

My Nemesis:
(https://web.archive.org/web/20170627020252im_/http://www.audiboost.com/images/imported/2014/01/attachmentphpattachmentid17031stc1d13887-1.jpg)
Title: Re: Tire Question
Post by: ToyMachine78 on 07/04/2016, 03:37 PM
I would have never guessed this thread would generate this much activity lol
Title: Re: Tire Question
Post by: wildfruit on 07/04/2016, 05:03 PM
Why are BMW's V8 engines so terribly unreliable compared to their almost bulletproof straight 6 variants?
Title: Re: Tire Question
Post by: SignOfZeta on 07/04/2016, 11:53 PM
BMW:

I had a similar diagnosis to a totally different problem. Long story short, actual cylinder volume and injector depth is crucial nowadays. Even something as minute as a copper washer of incorrect thickness can made a DI engine fuck up.

I know this because at work (engineering lab, not a shop) we had an incorectly machined head and and we fixed it by sanding down a washer. This was a cheap American SFI V6 (yes, they still make them) where we had installed pressure transducers in all the cylinders and one showed a trace absolutely in line with the other cylinders but at all points lower pressure. Nobody could figure it out until we had a guru from elsewhere in the company who eventually determined that the bore depth for the TD was wrong (not usually present, had to be machined by hand), in comes the sanded down washer. Being a guru he was able to tell us exactly how thin to make it to .001".

Btw, my TDI has pressure transducers in the glow plugs so maybe newer high end engines have adopted this as well. It would be way more helpful than just crank angle and while it's an outrageous expense we're talking about cars that depreciate more in their first year than the cost of the average car so fuck it.
Title: Re: Tangent - Brake Failure, Drum Overheat, Brake Fluid Vaporization...
Post by: NightWolve on 12/16/2016, 10:08 PM
Quote from: NightWolve on 06/15/2016, 04:59 AMAnyway, I had a weird/dangerous experience not that long ago worth pointing out on the subject of the importance of checking your tires from time to time, at least visually! My brakes were going out and I had to keep pumping the pedal to achieve slow down as I was going to a MicroCenter store pretty far away from me in another city!

It was pretty WTF cause I had changed everything myself over the years, the brake lines/pipes, calipers, hoses, drum shoes, drum pistons, etc. and it worked fine for years, so I was pretty upset! The car pretty much runs on mostly AutoZone/AdvanceAuto parts!

So, I stopped the car in a parking lot before getting there, popped the hood and noticed I had full brake fluid which left me not really knowing what the hell was going on (was thinking maybe the booster was finally going bad maybe)...

Well, I got to my destination safely by going slow and pumping the pedal as mentioned, parked, got out and somebody saw my front passenger-side tire was extremely deflated so he pointed it out to me. I was like, "Oh, thanks, f--k, so maybe that's why?!?!" A gas station was across the street, so I refilled it there for some quarters because I didn't have my supply box which had my 12VDC car light/air compressor in it. Sure enough, brakes worked fine again, so WTF ??

I never heard of this behavior due to low tire pressure or practically a flat tire... Never happened again as I try to remember to do visual tire checks, but I don't trust the car like I used to... I'm tired of looking at the rust anyway, so I'll be looking for a new one in the near future and will likely switch to a manual transmission also.
Hey guys, I wanted to update this when I got a chance... I figured out why my brakes were failing after driving around for a few miles on the highway and it's a safety tip worth mentioning...

So, long story short, last time I rebuilt my drums 8 years ago, the frame I had to get from a junkyard had the metal components to enable the star wheel to tighten the brake shoes when you pull the parking/e-brake up and down... I used to use that to keep 'em tight thinking that was a good idea... Well, it wasn't. For some reason, only the right side overtightened and before this happened, I was hearing lock noises on that side for about a month and was intending to have a look, well, check it out (nasty overheat, cracked the padding, ruined the rubber paint job I did, etc.):

(https://s5.postimg.cc/xsqmv9yhv/IMG_20161017_130216.jpg) (https://postimg.cc/image/xsqmv9yhv/) (https://s5.postimg.cc/hvruyk63n/IMG_20161017_130226.jpg) (https://postimg.cc/image/hvruyk63n/)
(https://s5.postimg.cc/bjcpoq31f/IMG_20161017_130238.jpg) (https://postimg.cc/image/bjcpoq31f/) (https://s5.postimg.cc/810psc25f/IMG_20161017_130248.jpg) (https://postimg.cc/image/810psc25f/) (https://s5.postimg.cc/587i8b1sz/IMG_20161017_130255.jpg) (https://postimg.cc/image/587i8b1sz/)

Scenario: You drive fast for a few miles on the highway, the shoes would heat that drum up rapidly, I mean, it was burning hot if you'd touch it, the wheel cylinder with brake fluid absorbs some of that heat, enough to evaporate DOT 3 brake fluid, AKA Fluid Vaporization, next thing you know, you're having to pump the brakes, the pedal goes all the way down and you're not stopping...

Anyway, those are the before photos. I got new brake shoes under lifetime warranty with my AutoZone account since I bought a pair 8 years ago. Bought a new spring set as well for $12, but the nightmare scenario where the bleeder valve was seized occurred, it broke on me, so spent another $13 for a wheel cylinder, and $5 for a copper/nickel brake line 12" in length because I want the corrosion protection and it broke too... I had all the needed grease and anything else needed, and got this done in October, so the car was set for winter, just was too busy to stop by and share the story.

ProTip: You can buy newer DOT 4 fluid for a few more bucks, and add about 50 degree more overheat protection. I'd do it if you've got an older car that still runs on DOT 3. Another thing I learned.

Well, FYI to any car buffs... Drive safely... Don't be me! :P

Oh, I should also mention I eliminated the metal component to auto-tighten the brake shoes with the parking brake... Each shoe is 1/4" of material, at best you lose a half inch on each side when it wears out, so your brake pedal would only go down about an extra inch as they come close to the end of their life... I'd rather just tighten manually from behind the drum with the car jacked if ever needed.

Another detail, I didn't know much about cars when I originally got it in '98 and eventually had a case where they wore out and ruined the steel drum, so those had to be replaced too way back... But yeah, car's been braking fine now, problem solved! It was quite bothering as there was no leaking fluid, so you wondered what the hell was going on, thinking the power brake booster was maybe going bad or the hoses were weak...
Title: Re: Tire Question
Post by: blueraven on 01/03/2017, 06:40 PM
Glad your car is fixed, Nightwolve. I had a similar problem with my Honda recently. Bad hardware and a leaking wheel cylinder.

And BMW, You're spot on about the BMW school. Not that I ever worked for them, but went through a similar situation when I got trained at WyoTech, and then went to work for a shop.

Quote from: SignOfZeta on 05/28/2016, 08:42 PMBecause they don't care.
For the win.