Guess TPMS may be a "nice to have" feature, but...

I wrote a few weeks ago about leaving my lights on with a 6 year old battery. I learned how to open the front hood with power to the fuse box. Installed a new battery and some dash lights came on. It turns out everything is ok except the TPMS. I replaced tires a in January 2013 (6 months ago), but not the TPMS components for each tire. They were probably on their last legs, but they all gave up the ghost trying to communicate with a dead battery.

Bottom line: I am going to live dangerously w/o TPMS and with an obnoxious warning. At $600 for a set, plus remounting and balancing wheels, about $800 total, I think I can live like we all used to w/o TPMS

A while ago, when I removed my steering wheel, I inadvertently generated an airbag warning light. My Durametric was home, 1500 miles away; it wasn't going to be of any use to me in the short term.

What WAS of great utility was a piece of black electrical tape, which very inconspicuously completely hid the offending warning light. HTH.

This might not be a helpful post, but check the owner's manual. I thought when a batter was dead/changed, that the car had to re-establish communicaitons with the TPMS? I could be wrong, though.

Guess TPMS may be a "nice to have" feature, but for those of us who have grown accustomed to the quick visual check of the tires before getting into the car, it is something that we would still do even if we had TPMS :-)

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RainyDayGarage
Guess TPMS may be a "nice to have" feature, but for those of us who have grown accustomed to the quick visual check of the tires before getting into the car, it is something that we would still do even if we had TPMS :-)

It is very much like the electronic oil dip stick..do you really trust it..."show me the money"

MIKELLIG

Used to be what I thought. Nice feature, but not really necessary as I regularly check my tire pressures.

I have to say, the system in our Porsches is much more useful than that in the BMW, which only tells you when one of the tires is getting low in relation to the others. (You still have to get out, pressure test or visually check to see which tire is low when the light goes on, as I found.) So it's possible that all four tires are down an equal amount of pressure and you still don't get a warning lamp.

I have 2 digital pressure gauges and a compressor which gives the pressure reading and also allows you to preset the pressure to which you want the tire adjusted. What has surprised me is the fact that all three AND the TPMS on my 981 S are in complete agreement. I keep my tires at the recommended 33 psi when cold. When I've had one of the tires read 32 psi on the TPMS, I've checked it with 2 of the gauges and each showed the pressure to be 32.5 psi, so it seems pretty sensitive. Not a bad thing.

It's comforting to know, specially when you get into the twisty bits, that all 4 tires are at the proper pressure. It's also interesting to see how the tire pressure changes under different conditions. I've seen them as high has 38 psi when driving hard on a hot sunny day. Drive on wet roads and the temperature always seems to stay at 33 psi.

Besides, it's while you're driving that you're most likely to pick up a foreign object in your tire. Better to know sooner, than later that you have a tire problem.

Because of the very low profile tires, getting a flat while driving, especially on a fairly straight roadway may not be readily apparent to the "seat of the pants." Also: then when braking or turning, the compromised situation rears its ugly head (or tail.)
Another situation, which I recall being discussed on TV when the SUV rollover problem came to light, is that those vehicles' tires have a very high sidewall, and getting a sensor warning as soon as possible regarding a low pressure situation is paramount to helping avoid a catastrophe.

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Laz
Because of the very low profile tires, getting a flat while driving, especially on a fairly straight roadway may not be readily apparent to the "seat of the pants." Also: then when braking or turning, the compromised situation rears its ugly head (or tail.)
Another situation, which I recall being discussed on TV when the SUV rollover problem came to light, is that those vehicles' tires have a very high sidewall, and getting a sensor warning as soon as possible regarding a low pressure situation is paramount to helping avoid a catastrophe.

I got into a roll on race of sorts with a motorcycle. At the end when I had to slow the car down considerably it darted to one side then the other under heavy braking. This didn't feel right at all so I pulled in to a gas station and found the right rear tire down around 6psi. I topped up the tire and limped into Fresno and the car was put in a lift and several nails were found in the tire. They were not there when I had the car inspected a day earlier before heading out. The rear tires were quite worn and I know worn tires are much more prone to picking up things.

TPMS may receive some negative comments from some but I loved TPMS in my 08 Cayman S and I look forward to the day when I get another newer car that has this feature.

My center dial display/OBC is always set to show TPMS reading. Knock on wood, all of my flats have been slow leaker from picking up nails or screws. Don't want to be riding on a rim before I know the tire is flat. Plus, it enterains me on roadtrips to see the pressure fluxuate with driving styles, rain, sun on one side of car, etc.

I would be interested to see how peak pressures on the track relate to measured pressures once you complete your cool down lap and make it thru the paddock to park and then check the pressures. Wondering if the pressure drops much from peak...

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Crooster
I would be interested to see how peak pressures on the track relate to measured pressures once you complete your cool down lap and make it thru the paddock to park and then check the pressures. Wondering if the pressure drops much from peak...

It's surprising how quickly pressures can change under some conditions. it's amazing how quickly the pressure can drop from 36 or 38 psi to 33 psi driving from a dry road onto a wet road with the same ambient temperatures. Makes you understand why the F1 drivers on intermediate tires start driving onto the wet areas just to cool down their tires (good), which of course drops the tire pressures (bad) in an effort to not wear them out too fast on a drying track.

Marc,

Interesting take on TPMS. I'd compare it (a little) with my experience 15 years ago with the then pretty new technology of anti-lock brakes, ABS. I slammed on my brakes to avoid an accident in an intersection where a car ran through a read light and hit the car in from of me (we had the green). And the pavement was wet. Hit the brakes and drove through and around the cars as I floated over the wet pavement. It was an amazing miss and at that point I knew I would never drive a car w/o ABS. ABS allowed me to brake and drive w/o the brakes locking (at which point you have no control of the car).

But, that is a bit more extreme than loosing air pressure in a tire. When I picked up my car, I talked at length with the mechanics about TPMS or not TPMS. First, if you have a blow-out, TPMS is irrelevant. So, we are pretty much talking about slow leaks. So, our discussion was about driver awareness. Like most, maybe all, folks on this board, I check my tire pressure regularly. I may now begin a routine of walking around the car every time before I get in to drive. We then talked about driving with reduced pressure on low profile tires. You felt a distinct difference at -6psi. I'm hard pressed to think that even driving down a straight highway (and my mechanics agreed), at say -15psi, I wouldn't notice that something was wrong. The car would "pull" in some manner indicating a problem. And, it might be noticeable with even less air loss (say -10psi). Some drivers may not notice things like this, but my guess is that Boxster owners aware of their cars driving characteristics will. The last time I had a slow leek was about 8 years ago driving in my wife's 2003 Jetta wagon on a highway. I felt something odd in the car's handling, pulled over, and sure there was a half flat. Changed the tire and I was on my way.

Bottom line: maybe I am trying to rationalize not spending $800. And, an extra $600 every time I replace the tires.

and for which TPMS would not be of any value a goodly number occur from driving on an under inflated tire.

Low tires are common. Where you live and drive look around at other vehicles and note the number of under inflated tires. Each low tire you see is a potential blowout.

I think I avoided a blowout in my VW Golf one night. After checking tire pressures at a station -- one tire had a slow intermittent leak due to a valve stem valve -- I headed west on I-40 through west Oklahoma into the panhandle of Texas. It was late and I got tired so I pulled into a rest area and snoozed. Afterwards to help clear my head I got out of the car to stretch my legs and noticed a rear tire was flat. Thankfully the VW carried a full size spare tire (oh how I miss full size spare tires!) so I swapped tires and that was that. But I noticed the tire was not only flat but worn down to the belts on either side of the tire's tread face. What had happened was when I checked the tire and found it low and added air this actually upset that damned valve stem valve and the leak got worse.

Had I not pulled over for a rest but instead continued to drive the tire could have very well suffered a blow out, well, not a blow out blow out but sudden/catastrophic tire failure. Maybe my being tired was partially to blame but I did not feel anything amiss with the car.

I'm getting lazy. Well, maybe not so much lazy as just very very busy. While I give the car a walk around before I head out first thing in the morning and during the walk around look for obviously low tires or other things amiss I don't check the tire pressures all that often. Since I do not have a place where I live to have quick and ready access to an air-compressor I have to check the tire pressures at the local gas station in case a tire is low. But because I'm so busy with personal/family business and still am trying to hold down a very demanding job a gas station stop of mine nearly matches a F1 pit stop for brevity. Instead of taking the time to get the station attendant to turn on the air pump and then drive over to the air pressure bay and check the tires I just give the tires a visual looking for any obviously low tires.

Surprisingly for both of my cars a low tire is not that obvious, at least one down say even as was the case of the rear tire of the 996 down by 6psi (from a nominal pressure of 44psi). In the case of the incident I mentioned in an earlier post I had no inkling tire pressure was down so much. The car felt ok right up until it didn't. (That impromptu "race" was probably a good thing.) As I mentioned I had the car roadworthiness inspected before heading out and the tech and I paid particular attention to the tires. They were worn but free of anything in them. (The tech did advise me the tires should be replaced but I was hoping to get 2K more miles from them and on the road call ahead and have a set ordered and waiting for me at the Springfield MO Porsche dealer a few days hence.) The big fat tires have stiff sidewalls. Also, because the tires are so fat (wide at least) they tend to trammel a bit and even when tire pressures are ok -- which I have confirmed by actually checking them -- the car, both cars in fact, are quite active in this regard. More than once I have pulled over in the Boxster or the 996 convinced of a low tire only to find the tire pressures ok.

With TPMS then one gets an early warning of something amiss. The risk of a blow out is reduced, which is why this system was mandated in the first place, to give drivers an early warning of a low tire before it progressed to a tire failure.

Yes, the cost is not insignificant. Perhaps had I gone through one TMPS replacement with my Cayman S I might feel differently now but I didn't so I don't.

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Bobtesa
Bottom line: I am going to live dangerously w/o TPMS and with an obnoxious warning. At $600 for a set, plus remounting and balancing wheels, about $800 total, I think I can live like we all used to w/o TPMS

Doesn't need to cost $800 as it would cost at a Porsche Dealership. See my post from last year..
[pedrosboard.com]

Guenter, thankst for the reference to your earlier post. I assume these are after market sensors, but that is ok if they are good. I also assume that they are a newer type that screws into the valve rather than needing to remove, remount, and balance the wheels. Is that the case? Please let me know where I can get these units. Thanks, Bob

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Bobtesa
Guenter, thankst for the reference to your earlier post. I assume these are after market sensors, but that is ok if they are good. I also assume that they are a newer type that screws into the valve rather than needing to remove, remount, and balance the wheels. Is that the case? Please let me know where I can get these units. Thanks, Bob

Here's where they were purchased. You may have to reselect your model year. I believe his (2006 997) required the 433 MHz version.
[www.titantpms.com]

You can't replace the sensors from outside the wheel. The mechanic deflated the tires, broke the bead at the valve stem, reached in and replaced the sensors without moving the tire around. Then he just pumped up the tires. Since the position of the tires stayed the same, there was no rebalancing required. Total price, parts and labour was $355 + tax. So your US price will likely be a bit less.

I see no reason why it shouldn't work.

Word of caution. Follow the instructions for letting the system "learn/recognize" the new sensors. Once installed you'll have to drive a few miles before the system reads the new sensors. Once that happens, everything will work like normal again.