craig_vette

My tires are getting low pressure warnings. Last night it started with the RR tire which I promptly filled up to 30 psi. This morning, however, it's back down to 22 PSI and two other tires are at 26 PSI.

Does this mean my TPMS are going bad? They are 16 years old. I haven't had time to check each tire with a manual gauge (at work currently), but I find it hard to believe that I'm losing air all at once.

Any thoughts? THanks.

CaseyJones

Possibly, but I'd check the pressure with a gauge to be sure that you don;t have other issues, such as leaking beads (my chrome aftermarket Speedlines were leaking at the bead due to corrosion) or the valve itself.

c5vetteguy

I doubt your problem is failing TPM sensors - they are battery operated and either work or don't. As Casey said, check your pressures with a gauge. If that coincides with your digital display (within a pound or two) then you have a leak at the bead or valve stem which is the TPMS itself. If you managed to get 16 years out your TPMS then that should be a record! They usually last 8-10 years, although some have made it longer.

Jeff T.

Definitely time for new TPMS...

Rico7142

Also probably you have a leak somewhere as stated earlier

rrwirsi

I had new tires put on new wheels 2 months ago. Last month I had a low pressure warning on one tire. Before calling the shop where I bought the tires, I tightened the valve stem nut that is outside of the wheel. Fixed the problem.

craig_vette

So I checked it with a manual guage and sure enough, it's reading low too at 25PSI. The other tires are all reading normally at 28-30PSI. I'll tighten the valve nut that extends to the outside and refill the tire tonight. We'll see what it does in the morning.

To figure out if its just a loose valve stem, would I try a kit like this?

Terry M.

I just had this happen tonight. Tires are new a month ago. Turned out to be a gasket around the valve stem was bad. A $5 fix

MikeWyatt

TPMS Sensors have a 10-year battery life. Mine failed at 11 years-6 months from production date; the symptoms were a low reading, a normal reading, then a high reading. I changed them and of course that solved the problem. Was it a faulty gasket?? maybe- but it was time.

If your car is 16 years old- somebody likely changed them once already- so it's not likely the TPMS.

Vetteman Jack

Take it one step at a time beginning with the sensor nuts. Go from there.

craig_vette

I jsut got back from O'Reillys and unfortunately they didn't have a quick-tool that would tighten the nut. I tried with a set of pliers but the rim is obstructing access. I was only able to turn it about half a turn. Anybody know what size socket I'll need? I'l have to get a deep socket b/c the valve stem prevents my short socket from getting to the nut.

Oh and yeah, it's a 2000 FRC with C6 wheels. Haven't had any problem for 3 months on new tires. I have my C5 TPMSs in my C6 wheels.

73Corvette

I'd tighten it a little bit and get a spray bottle with a little bit of soapy water in it and spray around the valve stem and see if it still leaking... if it is then repeat...
Valve stem needs to be at the bottom of the rotation...

Bill Vett

Also check each valve, some valve caps have a little "O" that sometimes gets jammed down in the valve and pushes against the shrader valve making it leak air.

craig_vette

This morning it was at 28PSI (last night it was at 30 after refill), so it seems to be leaking slower after tightening the nut with the pliers. I'll purchase a 12mm deep socket today and try tightening it fully and hopefully that's it. Appreciate all the help.

craig_vette

The DIC says "Rear Right" tire is low but it's actually the Driver side (left, correct? on the rear that's the low one (yes, I've checked all to be sure). Does this mean the DIC is wrong? Or does this mean the tire dealer inadvertently mismatched the TPMSs when he took them out of the C5 wheels and put them into my C6 wheels.

(I have C6 wheels on a C5)

c5vetteguy

More than likely. Just relearn the TPMS according to your owner's manual. Easy to do.