2001 BMW 330 - Mystery leak

My motor oil level is always fine, but the mechanic says I have a big leak which has compromised my bushings. I want to replace my front lower control arms. He said he can’t warranty the job because of my oil leak.

did your mechanic show you where the oil was leaking from when it was on the lift? did he tell you where it was coming from and how much it would cost to fix? Do you see oil stains on the floor where you park or wet spots on the underside of the vehicle when you look under it? if none of these I would look for another mechanic. at least get a second opinion.


Would think the mechanic would want to fix the leak as well as replacing the control arms,

There are several locations where that engine may leak oil, but the BIG leak location is the gasket between the oil filter housing and the engine block. That is a $5 gasket that costs $200 to replace because a lot of stuff has to come off to get to it. All 6 cylinder BMWs of that vintage are prone to this leak. By now, some have had that gasket replaced twice. Any owner with a decent collection of tools and a place to work can do it themself, but you will kill a Saturday the first time you do one.

Well known leak area on the M54 engine. Also valve covers and oil pan.

Thank you for this excellent information. I will have the gasket examined

What confuses me is that my oil level on the dipstick is always good. So I don’t know why the mechanic is telling me I have a big oil leak. Is it possible to have an oil leak when the car never needs additional oil?

A cup of oil can make a pretty big mess and will not move the dipstick level much.


Thank you for explaining. Now what my mechanic is saying makes sense.