Left rear mysteriously losing pressure

[M8 JTD]

Hi all,

I collected my M4 on the 21st of June and have now covered just under 3500 happy miles.

One small issue though - Every week my left rear tyre consistently loses 0.2-0.3 BAR (3-4.5 PSI) more than the others.

I've checked the tyre thoroughly - no nails/nicks/punctures + put some washing-up liquid around the valve - no obvious bubbles/air escaping.

Anybody else experienced a similar issue? - Any suggestions?

Many thanks,
Joe

[myzmak]

Seal leak. (ie: around the rim). It isn't set properly (or there could be a nick on the rim, but that is less likely if it is new)

Put some water/soap around the rim and you should find a place it is leaking a bit.

[GrussGott]

I had this on my e93, oddly the same tire - it was never diagnosed ... was looked at by the dealership and a tire shop with nothing found. I replaced the tires and haven't had problems since (same wheels).

It was kind of a pain in the arse, but one of those things. Sorry can't be of more help.

[Neil McRae]

get the dealer to replace the tyre on warranty.

[M8 JTD]

Cheers guys

I'm already booked in at the dealer next Saturday to have the Electronic Service History re-loaded (the service history tab is missing in my idrive).

I'll get them to remove the tyre, check both wheel and tyre then re-fit/replace.

[nachob]

Originally Posted by myzmak

Seal leak. (ie: around the rim). It isn't set properly (or there could be a nick on the rim, but that is less likely if it is new)

Put some water/soap around the rim and you should find a place it is leaking a bit.

Yes, if you can't find leak on valve stem or nail the seal is bad. I had this happen once and noticed one of the long moulding nipples that are about 3/4" long was bent into the sealing area producing a slow leak. I took air out of tire and pushed against sidewall to free the little flash and reinflated. Solved. Another time valve was not seating correctly and slow leak. Soapy water and spray bottle will find it.

[myzmak]

Happened to me with some new wheels on my current ride. Posted all about my issues, but tire shop ruined the tires when installing and bead would not seal properly so leaked and leaked.

If it is just a minor leak you can get a sealer to keep the leak from happening.

[M3 n X5M]

I have solved two cars losing air like this so far by tightening the nut around the stem just a sixth of a turn or less with some nose tip pliers. Just a hair of increase in tightness.

If this does not work then reseat the tire.

Dealers stated it was too slow a leak to detect each time, and that they needed to keep it overnight. My fix was free...

[stressdoc]

Originally Posted by M3 n X5M

I have solved two cars losing air like this so far by tightening the nut around the stem just a sixth of a turn or less with some nose tip pliers. Just a hair of increase in tightness.

If this does not work then reseat the tire.

Dealers stated it was too slow a leak to detect each time, and that they needed to keep it overnight. My fix was free...

This. But first like others above suggest throw some soapy water on tire and look for bubbles.

[M8 JTD]

Thanks for all the comments/advice guys - very much appreciated.

My dealer successfully reloaded my ESH this morning - Service History tab now visible in the idrive + showing the correct date/mileage for my running in service.

Now the bad news, the issue with my left rear turned out to be a nail very close to the side. New tyre being fitted next week - dealer discounted tyre down to £220 + fitting for free so could have been worse.