I inherited a 2008 Jeep Grand Cherokee from my late father and it seems like whenever the temperature overnight drops below a certain level, in the morning the low tire pressure light pops on. I never encountered this problem with any other car I owned, is this something inherent to SUV’s with all wheel drive?
It’s usually caused by the alloy wheels corroding at the beads, or the alloy wheels becoming porous.
A tire shop should be able to locate the leaks and fix the problem.
Set the tire pressure when the tires are cold, if you set the tire pressure when the tires are hot the warning light will be on the next day when the tires are cold.
What is the pressure in the morning? Do you have a good gauge?
Some of the TPMSs are horribly sensitive.
The “problem” is not inherent to SUVs with AWD. It is inherent to pressurized air. The rule of thumb is loss of 1 PSI for every 10 degree F drop in ambient air temperature. The 2010 Kia is my first vehicle with TPMS and it seems a bit oversensitive. The light will come on at 29 PSI which is only 3 less than the recommended 32 PSI. I got a good laugh out of the football “deflate gate” cheating accusations. The balls were inflated to the 12 PSI minimum in a 60F building then transferred to a 30F outdoor stadium. They soon dropped to an “illegal” 9 PSI. I guess Mother Nature should have been accused of cheating.
sgtrock21: actually that rule is only approximate. It varies with initial pressure and temperature.
If you start at 12 PSI, it drops about 0.5 PSI for a drop in temperature of 10ºF.
smokie: As stated above set you tire pressure when the tires are cold. I usually set them 2 PSI high to gain some margin, and also to help fuel economy.
Teste’s comment would apply if you have to add air to keep the proper pressure.
You may also want to check the owner’s manual (or the dealer) to see if there’s an “initialization” procedure for establishing a reference baseline for the computer on your Jeep. My car has one, and I need to “reinitialize” the TPMS system every time I get new tires. It’s generally a very simple procedure performed while sitting in the driver’s seat.