[h018871]

Just driving around I've noticed that the front right tire pressure gets 2 to 4 psi higher than the others....even though they all start out the same. I suspect it is because the auxiliary radiator vents onto that tire. The other side is the auxiliary inter-cooler which doesn't have much heat when just driving around.
The tires are even when at the track. I suspect there is less influence from the coolers and more from turning and heat from the brakes. Plus more heat will be coming out of the inter-cooler

the aux coolers do get heat out of the engine compartment as they should

[Vigilante375]

Only thing I've noticed is that my right rear keeps a constant 1 or 2 higher than the others.

Also, this is my first vehicle that shows the PSI on each tire. I found out that when you move tires around, the PSI on the DIC follows that tire. So if you're left rear shows 35 and your right rear shows 38, it's actually the opposite (physically).

Like I said, I never thought about it until I seen it a while back.

[DFW_Muscle]

Originally Posted by h018871

Just driving around I've noticed that the front right tire pressure gets 2 to 4 psi higher than the others....even though they all start out the same. I suspect it is because the auxiliary radiator vents onto that tire. The other side is the auxiliary inter-cooler which doesn't have much heat when just driving around.
The tires are even when at the track. I suspect there is less influence from the coolers and more from turning and heat from the brakes. Plus more heat will be coming out of the inter-cooler

the aux coolers do get heat out of the engine compartment as they should

I would say your theory is plausible. My thoughts on this are:

Our TPMS system is sensitive to electrical interference and it doesn't take much for one or two transmissions between the wheel sensor and receiver to be missed. It seems that they ping about once every 20 seconds. The receiver is located in the trunk where there is a lot of electrical gear located. I notice this as sometimes the pressure one one side goes up gradually, 1psi at a time, while the other side will lag behind, but then go up 2-3psi at once. Usually it is the LF on my car that lags. I also have brand new OEM sensors so they batteries are good.

I also notice that our front tires rise quicker than the rear, which I assume is because they are seeing more friction as a result of steering input. I keep my rear tires about 4psi lower than the fronts, but, all tires will increase about 4-5psi before reaching steady state after a long drive.

Do your wheels eventually level off at the same pressure?

Originally Posted by Vigilante375

I found out that when you move tires around, the PSI on the DIC follows that tire. So if you're left rear shows 35 and your right rear shows 38, it's actually the opposite (physically).

Like I said, I never thought about it until I seen it a while back.

Each wheel has a sensor in it that is "paired" to the receiver and set to a specific corner. The pairing procedure is in the manual (or you can buy the $10 tool on Amazon), in case you rotate tires or swap wheels, etc. Unless you reprogram, or repair the system, the receiver is still reporting the pressure based on the last known (programmed) position. It would have no other way to know you physically moved the sensor to a new corner, as the data transmission from the sensor is a simple radio signal operating at 433 mHz.

[Stephen12ZL1]

your theory is questionable because there are two aux radiators (one on each side) that exit exactly the same way. My car does not exhibit this air pressure weirdness on the street or on the track.

[ohsmily]

My car's tires increase pressure (heat) at the same rate when street driving. 2019 ZL1 1LE A10. I reset my TPMS sensors relatively frequently because I go back and forth between track and street tires.

[Tricksta]

my right rear shows about 3psi lower at all times

[Sakudog]

Originally Posted by h018871

Just driving around I've noticed that the front right tire pressure gets 2 to 4 psi higher than the others....even though they all start out the same. I suspect it is because the auxiliary radiator vents onto that tire. The other side is the auxiliary inter-cooler which doesn't have much heat when just driving around.
The tires are even when at the track. I suspect there is less influence from the coolers and more from turning and heat from the brakes. Plus more heat will be coming out of the inter-cooler

the aux coolers do get heat out of the engine compartment as they should

Have you swapped FR and FL tires, reset the TMPS and seen the same results?

[h018871]

I've reset the TPMS sensors with the orange box.
Good suggestion to swap side to side to see what happens. I'll do that after track day on Monday. Car has the track tires on it now (no 433 sensors yet).

The tires do not equal out after a long drive, right front is high. I should read the pressure with a gauge after a long ride, that'll confirm or eliminate a possible bad sensor.

The aux coolers are different, radiator and inter-cooler. Much different heat exchanging going on cruising around and flogging it at the track.

[gblaue]

Or, maybe your alignment maybe off. A little difference in toe can generate more tire heat, which can increase pressure.

[h018871]

I put the OE wheels with the 433MHz sensors back on the car, I also swapped the fronts left to right and reset the TPMS.
Everything is fine. All tires increase pressure and stabilize at a reasonable temperature. I guess they needed to be reset again??? I don't understand what difference that would make, but who cares......all is good now.
Thx to all for the feedback

[Biscuit.fr]

I have one ball lower than the other
Can tell a different friction when walking
I wonder if the temp is different from L to R,
But I can’t swap to check....
:-). :-)
(French humour)

Never had an issue on my Z, neither long distance nor track event.
All 4 tpms are fine

But Tx, the initial discussion was interesting
Happy that after reset everything is fine again

[ember1205]

Originally Posted by DFW_Muscle

Each wheel has a sensor in it that is "paired" to the receiver and set to a specific corner. The pairing procedure is in the manual (or you can buy the $10 tool on Amazon), in case you rotate tires or swap wheels, etc. Unless you reprogram, or repair the system, the receiver is still reporting the pressure based on the last known (programmed) position. It would have no other way to know you physically moved the sensor to a new corner, as the data transmission from the sensor is a simple radio signal operating at 433 mHz.

While that is seemingly true of how GM has implemented this feature, other cars may be different. My 2006 Acura TL required no special process when wheels were swapped / rotated and the system reported information based on position. I suspect that there are additional ways of possibly triangulating the signal to know exactly what corner it's coming from, but GM didn't add the extra antennas for it.

[Chutzpah]

Does anyone know where the TPMS module is located in the convertible? Sounds like it’s located in the back of the car somewhere in the Gen 6 (previous post)

I’m having intermittent loss of signal from the right front tire 20 minutes in, at continuous highway speeds. Doesn’t always happen and returns to normal once the speed is reduced. Could be self inflicted from a few electronics I’ve installed, but would like to check the connections on the module before I start shielding the after market stuff. If the fault happened when the car was stopped, it would be a heck of lot easier to isolate any interference. But, such is life.

[Vtor_ZL1]

Set pressure with good gauge, pressure goes up about equally all around.


Pressure gain also depends on alignment... or lack there of. If one tire is heating up that much more... get alignment chcked out.