Valve Cover sealing

Peter Coomaraswamy

Peter Coomaraswamy

Well-Known Member
Site Donor $$
Messages
3,792
Reaction score
907
Location
Austin, TX
On all the BMW's I have owned- both 4 & 6 Cyl, the valve cover has always sealed pretty well without any additional goop. My friends 2800 is leaking pretty severely and before I use form-a-gasket or some such stuff (in conjunction with the regular gasket) I thought I would ask the forum opinion. Do the covers warp on these models particularly? I guess the cover would be pretty easy to locate if I needed another.

Thanks,
 
yes mine was warped - lower in the middle and higher on the ends, I taped a bunch of 150 grit sand paper onto the kitchen granite countertop while my wife was out and wet sanded it flat. I also block sanded the area a little where the oil cap fits on the filler neck. Leaks stopped with just the gasket and no goop.
 
Thanks Steve, my neighbor in the business park has a machine shop but unfortunately the mill needed is not in his shop. The cover did not "warp" as much as a PO must have bent it, this guy could tell by the structural ribbing inside and said it really should be milled on the right machine or it will always leak. I hear you with the don't goop it up comment because the previous monkey did goop it up and it still leaked. Anyhow, the good news is that this one (1971 2800) runs really strong and this is really the last piece of the puzzle.

-appreciate the help
 
I had a problem with the valve cover on my S38 engine in my M5.
It keep leaking down the back and dripping on the header.
I would take it off and check it and put it on a flat surface and get a new gasket and it still leaked. This went on for months.
This valve cover is thicker and has more ribs inside so less likely to warp.
There is an oil return pipe lower down the back of the block but right under the head. I replaced the o-ring in that. Still leaking. I was so frustrated!
I took it off again and got out my 20x head loupe and sat in a chair and looked at it very close up.
I finally detected the smallest crack near the back lower corner and determined it was opening up with heat expansion and leaking there.
I had it welded and it's fine now.
Just shows how minute something can be and cause problems.
 
I have determined with the help of a psychic, that the valve cover was torqued down with something caught under the rear side and that caused a "bend" in the cover that starts at the attaching bolt holes. Since I have an extra cover I decided I would experiment with a file AND, I will consult the same psychic to see if there are any cracks. Such a silly thing to cause such a nasty problem. At least the only thing besides the cover that needs to be removed is the washer bottle and a couple of vacuum lines-

Thanks, and I'll report if my low-tech solution is of any use.
 
it helped me to lay it on a flat surface and check for light under the edges, and also to press on the ends to see where it see-sawed etc.
 
You must log in or register to reply here.
Back
Top