Oil Leaking from Head.

[Mikey J]

Hey all, I have a 1990 325is with 150,000 miles on it. The car runs like a champ. I changed the oil last fall just before storing it for the winter. I ran the car several times in my garage over the winter. About a month ago I discovered a big oil leak coming from between the head and the block between the #3 and #4 cylinders. So I figured that the head gasket has let go and needed to be replaced. I did a compression check prior to tearing it apart and all cylinders were between 160 and 165.

I pulled the engine and changed out all the old seals and gaskets to resolve some old oil seepage issues. I used Victor Reinz seals and head gasket and new head bolts. I torqued the head back down as per the Bently Manual 1st stage 22 ft lbs second stage torque 90 degrees followed by the third stage being another 90 degrees. All went well and the engine went back in. I have since put 250 miles on it and everything was fine no leaks.

The other day I was checking for any leaks and discovered a new oil leak coming from between the head and the cylinder block at the very rear of the engine at the #6 cylinder on the passengers side. New leak at a different location form the original problem. Not too happy at this point!!!

When I installed the head gasket I didn't coat the gasket with any sealant as I have seen some guys do. The car has never been overheated in its life, so I didn't check the head for any warpage, figured it was ok. Kicking myself in the ass at this point!!!

Is there anything i can do to stop this leak i.e. oil additive, or am I going to have to pull the head again and change the head gasket? If it comes to that I will be checking the head for warpage.

There is no coolant in the oil and no loss of coolant thus far.

[jlevie]

First make darn sure that the leak is truly from the head gasket. Leaking valve cover gasket or bungs could like like a leak from the head. If it is from the head, pull the head and have a shop check it for warp. In my experience a used head always has enough warp to justify at least a minimal surfacing cut (~0.005").

At 150k, I'd bet on the head needing new valve seals and needing to have the valves ground. Compression numbers might be good, but I'd bet on a leak down test revealing leaks at the exhaust valves.

[Mikey J]

The leak is definately coming from the head gasket. After taking a real close look it is definately seaping between the gasket and the head. I recently switched oil from 10W30 to 5W30 oil. The thinner oil probably isn't helping matters, but shouldn't be the cause of the leak. It is looking more like having to pull the head and having it milled. I guess I will probably have the head redone seeing that I have to tear it apart again. I hate doing things twice. :(

[SpecM]

also, do not use a Victor-Reinz head gasket, as they are know to leak oil

use an OE gasket, or a Grotze or Elring-Klinger (not sure about the spelling there haha)

and 5w30 is way too thin for an m20. use 15w40, 15w50 or 20w50.

[Mikey J]

Thanks for the info on Victor Reinz. I will be going OE on the head gasket. I just really hate having to do this job twice. Well I won't be pulling the engine this time. All the other seals and gaskets are not leaking, so I will just pull the head in place and have it rebuilt while I have it apart. I will be going to a 15W40 oil. I thought that being in a cold climate in northern canada the thinner oil would work better, but as I don't drive the car during the winter months, there is no sense in using a thinner oil.