Valve cover leak at timing cover

[MarcD]

Replaced the gasket while I had the cover off, now I have a significant leak where the head meets the timing cover. Top side by the water neck. I think I know the answer to this but I'd rather not send the cover to the machine shop to have a couple thousandths taken off. The cover is also out of square left to right which I found strange. 

 

I want to use a little RTV under the valve cover gasket at that joint. My friends say that's trashy and I should fix it the right way.  I see blunt has a silicone gasket that looks like it's thick enough to take up the space, so that's option 2. Has anyone used this silicon gasket with any success?  Or should I just pull the cover and machine it to the correct height? 

[visionaut]

Try a thicker gasket. And if you need a sealer, don’t use RTV..

 

https://www.bmw2002faq.com/forums/topic/131372-valve-cover-gasket-saga/

[Stevenc22]

Absolutely throw  blob of RTV (Honda Bond is my fav) on the timing cover groves. It will help.

[MarcD]

31 minutes ago, Stevenc22 said:

Absolutely throw  blob of RTV (Honda Bond is my fav) on the timing cover groves. It will help.

 

I don't have any Hondabond but I do have some Yammabond! 

[kbmb02]

2 hours ago, MarcD said:

Replaced the gasket while I had the cover off, now I have a significant leak where the head meets the timing cover.

 

Add: There's a recommended method-sequence for tightening the (8) bolts of the upper timing cover which gets it to seal (I believe the BMW blue book makes note of it). -KB

[tech71]

3 hours ago, MarcD said:

 Or should I just pull the cover and machine it to the correct height? 

Which is what? Thats normally done when head is surfaced and cover is attached.

If it didn't leak before should be able to seal it without doing that.

 

3 hours ago, MarcD said:

now I have a significant leak where the head meets the timing cover. Top side by the water neck.

Not sure I'm following you there, a pic is not that hard to post and so very helpful

 

3 hours ago, MarcD said:

My friends say that's trashy and I should fix it the right way.

Phhft! ( snort of derision )Tell them to get bent, fixing it the right way is stopping the leak with minimum effort.

 

3 hours ago, MarcD said:

The cover is also out of square left to right which I found strange. 

Huh? Again... would a pic kill you?😉

Try a small bead of Dirko or similar across the interfaces first.

Tighten the valve cover nuts in a diametrically opposed pattern

Edited August 20, 2023 by tech71

[Buckeye]

3 hours ago, MarcD said:

I want to use a little RTV under the valve cover gasket at that joint. My friends say that's trashy and I should fix it the right way. 

You have good friend and should listen to him or her. Otherwise six months from now we will see a post from you wanting to know how to eliminate oil leaks. Do it right the 1st time and be done with it.

+1 what kbmb02 said

[FunElan]

Mine does this and I consider it rust prevention at this point

[MarcD]

13 minutes ago, FunElan said:

Mine does this and I consider it rust prevention at this point

 

When the drops on the garage floor go from brown to black, that's how you know it's time to change the oil. 

 

2 hours ago, tech71 said:

Again... would a pic kill you?😉

 

It's hot out there, man. Real hot. Humid too. 7 men lost their lives taking these pictures. 

 

I think there is some slop in the mounting holes of the cover. I really want to loosen the bolts and see if I can line it back up with the mounting boss but the timing cover doesn't leak so it goes against my better judgement. 

 

 In hindsight I didn't need to remove the valve cover to install the header and replace the studs. Dumb. 

 

[Son of Marty]

I think you can get that top seam to line up better if you remove the cover and put a bb sized dab of rtv where the cover, head gasket, and block intersect then hand tighten the 6 bolts into the head, I use a 1/4 drive socket with a extension that I turn by hand, no handle,  tighten the 2 downward bolts then tighten the other 6 bolts and it may bring that gap down to where the gasket will seal. If not then you could try the rtv on the gasket at the gap or fix it right by having the cover machined down. To do that with the valve cover and gasket removed take a single edge razor blade slide it as flat as you can along the head and scribe a line on both side of the front cover right at the head and then get a machinist to cut the cover to that line or better yet transfer that measurement to the bottom and cut there.

Edited August 20, 2023 by Son of Marty

[tech71]

1 hour ago, MarcD said:

I think there is some slop in the mounting holes of the cover. I really want to loosen the bolts and see if I can line it back up with the mounting boss but the timing cover doesn't leak so it goes against my better judgement.

It kinda looks glued in place, loosening the bolts and trying to move it around will probably make it leak.

Might as well get new upper timing cover gaskets and take the upper cover off completely.

It didn't leak before install of a new valve cover gasket right?

Still got the old gasket?

 

[Hans]

Good luck getting that thing machined perfectly square. Been there, threw it out.

When tightening those bolts, put the main cover on loose and push down hard on it.

I'd  get s thick top gasket and goop it first.

Edited August 21, 2023 by Hans

[tech71]

2 hours ago, Hans said:

Good luck getting that thing machined perfectly square. Been there, threw it out.

I had better results than machine shop with a sheet of aluminum oxide taped to a piece of plate glass.