lokitoff

I bought a new IS 250 F-sport 2 weeks ago and the tire indicator drives me crazy. The low tire pressure light on twice in a week. I added up to 36pis (Recommended Pressure) and all tires went down after a few days. I went back to Lexus today for tire pressure. Every tire is okay but tire pressure is low only. Anyone has the same problem as me? Btw, my gas indicator did not rise up after I filled gas. The indicator started to rise up after I drove about 2 miles. Is that normal for a new car???? I need helps from you guys!!!

NebulaIS

I think I've read other users saying their fuel gauge would rise up slowly after filling. I haven't had that particular problem.

Can you clarify? You went to Lexus and the tires are OK but the INDICATOR is saying they are low? When you refilled did you use air or nitrogen?

lokitoff

I refilled on last Sat with air and low tire pressure light on today when I started my car. For the gas indicator, I refilled my gas and it did not rise up slowly until I drove about 2 miles.

NebulaIS

The gas I don't think is a big issue but worth mentioning to the dealership. Have you manually checked your tire pressure with a gauge? If you top it up with air and the ACTUAL pressure goes down then it's an issue with the tire or maybe your rim is damaged....if you topped up the air and the ACTUAL pressure is fine but the TPMS is going off then it's a sensor issue. Either way the dealership can help.

lokitoff

Today I went to Lexus and the dealership checked all the tires. There is no problem about the tires but my tire indicator shows the pressure decreases a bit after a few days.

lokitoff

The dealership pop the tire up to 40 pis but the recommended pressure is 36 pis. It is kind of wried

Dark9t316

Lower temperature will make your tire pressure go down, for every 10 degrees F, you lose about 2%. Not sure why the dealer overinflated your tires...

NebulaIS

Ya man sounds like they need to recalibrate it. Even with nitrogen filled tires the pressure will still fluctuate based on outside temp and tire temp...but the system is designed so that under normal conditions the TPMS warning shouldn't go off. I think mine are 35-36 cold and 40-41 after driving...outdoor temp has fluctuated from -5 to +25 Celsius (like it always does in Canada) and I've had no issues with my TPMS. You're in Cali so outside temp should have nothing to do with this...

lokitoff

Ya I think mine have nth to do with the temp right now. But I don't know why the dealership overinflated my tires either

steco

iTrader: (2)

did you check your tires for small nails that might let air out slowly over night? that's might be the problem why the tires are loosing pressure.

lokitoff

I checked with the dealership today. There is no nail actually and every tire is normal, but mine tire pressure keep decreasing down by a bit

Dark9t316

Try old fashioned manual gauge test to see if something is wrong with your TPMS