My BMW e90 eats 4 litres of oil every 4 weeks

[CR_bm_e90]

My e90 eats 4 litres of oil throughout the course of 4 weeks I know 100% this is not at all normal...I know my car is definitely burning it as I get smoke through acceleration and gear changes especially at any speed...any ideas what could be causing it and is there any easy way of finding out why its going through so much ...any help or advice is appreciated...many thanks

[Tyre Smoke]

Mileage?

Engine is on it's way by the sound of things. The cat must be full of carbon

[ClaphamGT3]

Too little info to be really definitive here but one possibility may be a blocked oil breather

[CR_bm_e90]

Thanks for the reply
Mileage is 105447 and it's a 2008 model so just under average mileage for the year of the car

[ClaphamGT3]

Petrol? Diesel? Lots of short journeys? Regularly serviced?

[CR_bm_e90]

The car on 1st start up of the day is a nightmare smokes a bit and it's very fumy ...when it's running seems to idle ok .. ... don't really know what else to say as the main problem is the oil consumption and obviously I have a big fuel consumption also ..

[CR_bm_e90]

Bmw e90...2008 ...318i m sport ...petrol
Car is used as a general run about averages about 30 miles a day ..school run about 12 miles each way ...into town etc
Yeah its been regularly serviced as its actually on finance which I took out over 3 years and I have a year left

[RichB]

Might be ring or two gone, probably needs a rebore, new pistons, may as well do full engine rebuild (or scrap it).

[CR_bm_e90]

So the problem is obviously bad and not going to be a simple problem to fix ?

[Elliot2000]

If it’s poor starting, good chance injectors are leaking overnight , washing the bores and slowly diluting your oil with petrol. Open the oil cap and see if it smells of petroleum fumes.

Diluted thin oil and washed bores will cause massive oil consumption

Get it checked by someone who knows these engines well, but my best guess would be it will need injectors replaced or reconditioned. If you rev it up to the red line does it pop and crackle as the revs drop back to idle? That will be a sign that it’s overfuelling anyway

It could also be plenty of other things- but the rough running on cold starts sort of points in that direction.

Edited by Elliot2000 on Sunday 25th August 19:59

[Tyre Smoke]

Sounds like it could be injectors leaking down. But I would expect tappety rattle too.

Either way, doesn't sound cheap.

[SD_1]

I had an Astra do this years ago, mechanic diagnosed it as either piston rings or valve seals. It went through a litre every 100 miles and turned the spark plugs so black the car ran like utter crap unless you took them out and cleaned them.

Bottom line was that it would be a huge job to sort, and wasn't worth it on a cheap old car.

[Quavers]

Petrol BMW - valve stem seals will be the issue - or part of the issue.

[Touring442]

As it's a 2008 N43, the best cure is to get rid of it ASAFP. They are known for ring wear as was the POS N46 before it.