Lost of pressure

[teog60]

Hi all,
few days ago, It appeared a warning about lost of pressure in the Left Rear tyre.
I checked everything and I restored the correct pressure (2.4 bar on the front, 2.9 on the rear), and I reset the system.

Yesterday, after a light car-wash, It appeared a new warning about lost of pressure, but in this case: ALL THE TYRES.

Any idea??
Cheers

PS: 296 rims!!!

[ManiacGT]

Clearly, as you've pointed out 296 rims in your message, you're concerned its the wheels. So, first thing I don't really need to tell you is go to a garage and have the wheels checked to allay any fears.

On topic however, if you've got an error showing on one wheel one time then all wheels the next time, its likely an electrical issue unless you've driven through a road covered in nails.

Have it back to a dealer and have them check the cars own error codes.

[Mr. ///M3 RD]

Get a good pressure gauge and check the air pressure (I believe in "seeing is believing" ~ too many times the electronic feedback was not right in my experience).

Having said that, definitely a great loss in air pressure points to wheel crack, make sure they use a water bath to check your rim if you suspect a crack.

~ small air pressure loss here and again ... Points to a hairline crack (very tiny crack).

~ major air pressure loss ... Points to a open crack (hairline crack opens up and let's air escape).

Hope this helps.

PS. Note however that major ambient temperature changes will affect all four tires and having a good pressure gauge will help you out here. I have one that is a compressor and pressure gauge, the kind of gauge that is part of the air supply hose giving you real pressure feedback with dial graduations of 2 PSIG. Money well spend for a small portable one you keep in your garage. The photo below shows mine I think I paid $42- there are several types on the market ... you may even get one that BMW sells for the M3's



HERE IS ONE FOR SALE ---> CLICK TO OPEN

[teog60]

I can't believe that every 4 rims are cracked in the same time! (I hope that this is impossible).
I think is an electrical mistake.

I'll for changhing tyres next week (In Italy is mandatory to use M+S tyres in winter), and I try to test the pressure-check system with the winter rims (17") and tyres...

Cheers

[CeEl]

Originally Posted by teog60

I can't believe that every 4 rims are cracked in the same time! (I hope that this is impossible).
I think is an electrical mistake.

I'll for changhing tyres next week (In Italy is mandatory to use M+S tyres in winter), and I try to test the pressure-check system with the winter rims (17") and tyres...

Cheers

Not sure about the Euro spec cars, but in the US, you have to reset the TPMS after you change tire pressure ...