Z4MC - Normal to get TPM warning at cold weather?

[Erhan]

Last night on my way home, right after starting the car, yellow tire pressure monitor warning came up. Tires were looking OK. It was around 25-30F. I have the stock tires & wheels.

I checked the tires this morning too, they looked good. I didn't run the car today though.

Just want to check, if it was due to cold weather... any inputs?

thanks.

[GeorgeT]

You need to check the pressure in your tires. When the air in your tires cool, it contracts and thepressure is lower. I get this warning almost every winter when it turns cold and the pressure is usually down 20%-25%.

[F360C]

Did you actually even check the pressures? If if by saying they "looked ok" are you just meaning that you think they visually look okay?

[Erhan]

Originally Posted by F360C

Did you actually even check the pressures? If if by saying they "looked ok" are you just meaning that you think they visually look okay?

Yes I mean visually OK. In other words, they were not flat or substantially deflated.

[Matty C]

Yes change in Temp will change your tire pressure. Also hitting a pothole can trigger this. Carry a tire pressure gauge with you and check the pressure at least 4 times a year.

[Huz-Z]

I suspect that your tires are just slightly low on air. In warmer months, the pressure remains high enough so the sensor is not activated. But now that its cooling off, the pressure is falling just below the threshold.

Huzz

[Rick Hunter]

Very normal.

Check pressures and adjust.

[AWM3]

You have an air pump with a built in pressure gauge in your car under that ugly hump over the battery in the trunk. If you wanted to you could have hooked up the pump that comes with the car and checked the pressures right there. They probably are all low. That wouldn't be much fun in a parking lot in 25 degree weather. But you have everything you need right there in the car already.

[jmillet]

Originally Posted by erhanh

Last night on my way home, right after starting the car, yellow tire pressure monitor warning came up. Tires were looking OK. It was around 25-30F. I have the stock tires & wheels.
I checked the tires this morning too, they looked good. I didn't run the car today though.
Just want to check, if it was due to cold weather... any inputs?
thanks.

Shame on you
Invest $20 in a good analog, 0-60psi, straight chuck tire pressure gauge. http://www.getagauge.com/Accu-Gage-HSeries.cfm
I run my fronts at 32 psi and rears at 30psi. Before departing for Astoria last Wednesday I checked pressures and found the fronts at 28psi and the rears at 26psi with no warning light.
Ambient temperatures as well as elevation have a significant impact on tire pressure. In August I drove from sea level (Seattle) to Paradise on Mount Rainer (5000 feet) and my warning light came on.

[Erhan]

Thanks for all the replies.. Will check and pump up the pressure. Hope I won't forget to deflate them when the summer comes

[AusTTin Bob]

Could well be just the cold weather. My TPMS light has come on exactly twice since I got my car in June - on the two coldest days so of the year so far. Where I park overnight, the morning sun shines on the front right tire while the others are in the shade. So when I start up, the computer feels that one tire having higher pressure than the others. It straightens itself out by the time I've gotten to work.

[pungo]

The cold causes your tires to contract and you’ll lose about 1 pound of air pressure for every 10 degree Fahrenheit drop in temperature. I check mine each month getting in to winter and usually need to add a couple of psi.

I think the system measures the circumference of all the tires when you calibrate it. Then will error if it finds any difference between tires. If they all loose the same amount, I don't think it will detect it. A better system would actually measure the psi in each tire and give an error when it found any or all to be off from the recommended psi.

[epbrown]

Originally Posted by pungo

I think the system measures the circumference of all the tires when you calibrate it.

This is only on 2003-2006 Z4s; from 2007+, there are actual pressure sensors in each tire.

It's the cold - my Smart Fortwo did the same thing as soon as we got sub-freezing temps here in Chicago. I stopped to top them off at the local Shell station and found there was a line of people waiting to do the same thing, all of them with newer German cars.

[Erhan]

I checked the pressures over the weekend with the M mobility kit, and all of them were 30.5psi... But I still have the damn warning light. I guess I'll buy the tire gauge Jim suggested. Maybe the M mobility kit is not accurate? Or maybe the sensor is malfunctioning.

[GP20]

I might be stating the obvious, but did you try re-setting the pressure monitor and see what happens?

[Erhan]

Originally Posted by GP20

I might be stating the obvious, but did you try re-setting the pressure monitor and see what happens?

Yeah several times.

[xJxDx0926]

Originally Posted by F360C

Did you actually even check the pressures? If if by saying they "looked ok" are you just meaning that you think they visually look okay?

Originally Posted by erhanh

Yes I mean visually OK. In other words, they were not flat or substantially deflated.

Even if they visually look ok we have run flat tires you are not going to notice. My light came on last friday night and they were at 27PSI.

Just fill it up press the reset button drive around a bit and it will go away.

[Erhan]

Originally Posted by xJxDx0926

Even if they visually look ok we have run flat tires you are not going to notice. My light came on last friday night and they were at 27PSI.

Just fill it up press the reset button drive around a bit and it will go away.

Z4 Ms do not have run flat tires. Now the weather is 45-50F and the light is went away..

Interesting part is, when I checked the tire pressures with M mobility kit, all were 30.5psi...