E30 Zone

Are M20's known to use a bit of oil? Mine's doing 1L every 1600 miles on average. Power is still good and mpg too. No signs of blue smoke etc so the engine really isn't that bad, it just seems to use a bit of oil.

Any thoughts?

Probably not that unusual but personally i'd want to know why.

probably leaking rather than burning it up.

No drips on the drive but it does have a slight leak as it's wet around the block. Wouldn't have thought it would leak that much without leaving some on the drive?

Most likely a leak but if you say it doesnt leave stains on the drive then maybe its burning it through worn rings or valve stem seals.

How many miles has it done.

maybe the oil pressure switch ?

mine leaks a bit, you can find it wet around the block but it never leaves patches, the loss will happen when its running and hot, at higher oil pressures, so you will only leak on a run, when your still on the drive at idle you wont leak.

In my experience they don't use much. It suggests to me that you are losing it somehow.

where are the usual places to find leakages?

front of the block from either the cam seal (like mine) or the crank seal or the plastic bungs in the head, back of the block from the crank seal or plastic bungs.

I have found after 10+ years of ownership of e30 327i that oil use is somewhat related to the speed the car is driven at and the weight of oil that is used. Generally I will use about 1/2 a litre in 10,000kms. If the oil is say 5-40 synth it will use more than 15-50 synth over the same milage period.

Anyway.....1 litre in 2,000kms sounds too much. Check compression of the cylinders and if you have a few pots that are low check if its the head or rings. If its the head is a much easier fix.

bss325i wrote:Most likely a leak but if you say it doesnt leave stains on the drive then maybe its burning it through worn rings or valve stem seals.

How many miles has it done.

I was wondering about rings/stem seals but usually you'd see a bit of blue smoke and I'm getting none at all (that I can tell). Probably just leaking a bit as it is wet down there.

It's on 107k miles.

jermyns wrote: Check compression of the cylinders and if you have a few pots that are low check if its the head or rings. If its the head is a much easier fix.

TBH I'm quite tempted just to bin the B20 in favour of a B25 and have an extra 40bhp to boot. Best excuse I can think of for power upgrades! Although the more I think about it the more I think it's just a leak rather than actually losing oil. The sump guard is quite wet...

in that case clean the front of the engine off with some break cleaner and see if it comes back.

Yeah, I think I'll do a bit more investigation on this, I've got the cambelt to change so might have it all apart at the weekend and take a proper look