oil in the expansion tank?

[tappyt]

hi guys and gals....new to the forum....but not new to the beemers...had 2 525s and now just about to purchase my first 325i....my question is i have oil in my expansion tank and at first nearly had a hissing fit thiking oh nooo my head gasket has gone but was then told it could be the oil cooler mixing oil in with the water...now bear with me now....there is an oil leak coming from right where the oil filter is, right where the pipes run to the oil cooler radiator and its worse after its been driven but seems to slow when coming to a stop....the car still pulls well and has no white smoke on start up just a slight puff of blue but not a massive cloud....radiator fans cut in ok and it isnt over heating so can anyone help by telling me if the infomation i have been given on the fact that the oil cooler part of the system can leak oil into the expation tank and cause sludge there is true or not or am i looking at a head gasket job.....hope its just the oil cooler gasket as its not too expensive from a main dealer...any help or advice will be gratefully appreciated..thanks guys

[wildeian]

The oil cooler uses air-flow to cool the oil, not water.

I don't see how this could be the cause, although oil in the header tank doesn't necessarily mean head gasket.

Have you tried flushing the coolant?

[tappyt]

not as yet....i am planning on doing that though but after i get the oil leak fixed....it was a mechanic i know on a personal basis that told me this after i spoke to him about the problem with the oil in the water and then about the oil leak and straight away he said that where the oil is leaking out of the gasket joing the oil filter to the head it may be passing into one of the water ducts...or even the casing which the oil filter attatches too may even be cracked or pourus due to it being so close to the exhaust manifold and be getting in from there....engine still pulls strongley though so what else do you thik it could be.....any idears

[tappyt]

Anyone got any thought on what else causes oil to get into the expansion tank

[Brianmoooore]

Anyone got any thought on what else causes oil to get into the expansion tank

Yes! On a 325, I'd put money on the problem being a cracked head around and through either of the two rearmost cam bearing journals.

[Brianmoooore]

Could also be the result of insufficient flushing after a recent replacement of a cracked head of course.

[tappyt]

its a1990 m20 325 i belive....strange that it pulls so well....the oil lights are on both on the dash and the roof display but thought this was down to the oil leak......would a compresion test find these cracks...also what should a good compresion reading be on these old girls???......so if its cracked then its a new head i take it...is this a bitch of a job on these lumps??

[tappyt]

to be fair it doesnt look like its had a new head put on anytime....its a bit of a dog at the moment but its been family owned since new and its only done 110000 miles full service history which is not bad considering she is 17 years old now...and it only cost me.........WAIT FOR IT......£150.....but she hasnt been polished for i would say about 2/3 years and the LADY who owned it of corse checked the oil every week(NOT) but heh i like a chalenge..wink wink

[tappyt]

so we can definatly rule out the leaky oil filter housing?????

[Brianmoooore]

The cracks are nowhere near the combustion chambers - it's the bearing journals for the cam that crack.
Will have no effect on performance at all.
I hope you mean the oil service light on the dash, not the oil pressure light!

[tappyt]

yes sorry the oil service light.....so is the problem with the cracked journals terminal......what other symptoms would i be getting as the engine is not tappety......in regards to the copression though what sort of readings shoul i be getting on a healthy engine as im gunna test it myself and se whats what

[Brianmoooore]

The only symptoms, until secondary symptoms start to show up due to overheating/lack of lubrication, are oil in the water and water in the oil.

[daimlerman]

tappyt,I had this problem a while back,engine ran well just as you say,but it was mixing its oil and water.Try removing the rocker cover and have a look at the two rearmost cam journals,with the engine running you may be able to see the crack.I have not been able to find anyone who is prepared to weld such a crack up,the next time I need to do this I will pay up for an exchange head with GSF.The cost of buying and recondishoning(?)a s/h head is almost as much and that way you get a warrenty.

[BM_Jay]

I just had to change my head as I had the same issue, oil in the water tank. Craked head.