BMW M30 engne oil leak

[magnus]

I have just aquired a classic with this engine. Problem is that it has the well known slight oil leak from the front of the block. I find that the leak does not start until the engine has been running for about 5 minutes and is continuous rather than "weepy" suggesting a pressure related problem. I am told that the problem is not uncommon. I would be most grateful for advice from any body who has had this problem and dealt with it

[jon.evans]

magnus said:

I would be most grateful for advice from any body who has had this problem and dealt with it

Hi Magnus,

There is a bracket on the front of the engine which holds the crank position sensor. One or both of the bolts that attach it will have worked loose. Because they screw through the timing chain cover, when they work loose they let oil leak out through the holes. Usually it isn't immediately obvious where the leak is coming from because the flywheel throws the oil all over the place.

Clean it all up first, then remove the accessible bolt and put a bit of thread lock on it. The other bolt can't be removed with the flywheel on so you'll just have to tighten that one.

Pics and procedure on my site here:

M30 oil leak fix

Jon