twister

Now since we are in single digits here on East Coast, I get every morning "low tire pressure" warning until approx 10 min of driving while tires "warm up" I understand, this is plain physics and material properies change at temperature extremes. But it makes me wonder, couldn't they test it in Japan or here in US over the various temperature points to set tire pressure limits accordingly not to trigger it at very cold?

Anybody else experiencing the same in the morning at extreme cold when low tire pressure warning stays for 5-10 minutes? Could it be that in my case the actuall tire pressure is close to trigger alarm threshold and cold temperature just pushes it over the limit?

marshmallo

I got the TP warning this morning and I thought I was right at the
edge just because it was cold, but my front right tire was in fact
at 25psi

GreatSmile

It didn't do it on mine this morning and we had 9 degree when I left the house. You might want to recheck your pressure. Once you have all pressure checked and re-intialized the sensors, that should take care of it.

Jace7

Twist, you have nitrogen right?
if not, get it, that is the first thing and will probalby fix.
If you already do, it shouldn't fluctuate more than 2 lbs. even if it was 10 in the morning and 50 in the day...

twister

Don't have nitrogen where do I even get it?

I called my dealership and they told me its a normal thing to get the warning which goes away afterwards in cold weather. But, I don't buy that. What is the pressure supposed to be, 32 or something like that? Probably will have to fill those puppies up and re-init TP.

Off-topic, Jace I see you sold your nightvisioned 550i? Now your are back from Jace007 to a regular Jace7

Jace7

my tires have the green caps on the air valve. My dealership fills mine every time, and they originally put nitrogen in them at purchase.
It's much better and more consistant.
It's what goes in airplane tires for a obvious reason. MORE stable and more constant. wouldnt want the pressure flucuating at -150 degrees when your flying...

try it out, you'll notice a difference, not in ride, but in consistancy and relaibility.

marshmallo

While I was filling my low pressure tire in 16 degree weather I gave
some more thought about this thread. You might want to make sure
ALL the tires are OK just in case a single tire is marginal and is triggering
the warning. In my case one tire was at 25psi while the other 3 were
at 32psi. I hear that is a very undesirable condition for an AWD car...

GFC350

Ive had this problem before in cold weather. It ended up that one of my tires was low on air. I filled it up and it was fine. Just coincidence that it happened on a cold morning. Dealer checked it out during an oil change. Found a nail, patched it from the inside and its fine now. Since then, after a cold morning again, low pressure once again on one of the tires. Havent gotten a chance to check for nails yet. Just my luck, I guess......

larrs

Forgetting about the nitrogen mentioned above, a tire inflated with plain old air will lose about 1 psi of pressure for each drop of 10 degrees in temperature. Also, tires typically lose pressure slowly over time (I've read that 1 psi per month is normal). So ... let's say you (or the dealer) set the pressure at 32psi two months ago, when the temp was 40 degrees. Now, two months later, and 30 or more degrees colder, the pressure is down around 27, probably enough to trigger the warning. Once you drive for a while, the tire heats up and the pressure increases (this is why you need to check and adjust pressure when the tires are cold), and the warning turns off.

My opinion is that you should set the cold pressure to correspond to the typical temperature. If you want the tires at 32 psi when it's 10 degrees outside, then on a 40 degree day you would set the pressure at 35 psi (before driving the car).

I think the TPMS is working as it should. It's telling you that the pressure has dropped more than 5 psi below the calibrated pressure. Time to add air to the tires.

clexusking

They really should test those pesky tire pressure lights better so they never come on!

SGT

I have my tires at 40 psi during winter and I never get the low pressure warning.

gsCrazy

iTrader: (1)

is the ride harsh with 40 psi??? i usually put 31 psi in my 2gs and even when i have it only 2 psi higher at 33 the ride is noticeably harsher...

SGT

I don't notice any difference than when I used to have it at 35 psi. Then again, maybe it's just me.

Jace7

it is.

just kidding.

Wronglane

About a month ago,my wife told me the warning light came on.The next day the tire was very very low,almost flat.I filled it with air and noticed that it was losing air through the valve stem.She took it to th e dealer and they replaced the stem in the valve.......problem solved.

Every two weeks or so,I do check pressure,and they typically need some,especially since the cold weather has setteled in.....no big deal ,it's normal. Last week,when I checked pressure,three tires were at 30 PSI which never triggered the warning light(not sure of when the light should be triggered). Anyway,I run my tires at 44 PSI for better mileage and also due to the fact that tires will lose some of their air.