2.9 Valve cover question

[LonesomeSTX]

While I am at it, I also have a valve cover question for my 87 2.9. I know they are prone to leak. I have read the tech articles and have taken all the steps I know to take. I used the higher quality FelPro gasket, retorqued the bolts after about 100 miles, and made sure the lip was straight when I reinstalled them. Yet, the damn things still leak. What did I forget?

 

[drsvox]

RTV sealant?

 

[adsm08]

Did you use the rubber gaskets, or the cork ones?

 

[RonD]

I only use rubber if I know I will be removing the valve covers often.

Cork is the only way to fly, IMO.
It swells over time helping to seal any future gaps


The oil in the valve covers is not under any pressure if PCV Valve is working well.
If it's not then you are adding pressure inside the valve covers which will promote leaks.
So make sure PCV Valve is working as it should.

The oil sits at the lower edge and back of valve covers until it drains back into the oil pan.
If that's where it is leaking from then valve cover could be warped

 

[LonesomeSTX]

I got the rubber FelPro gaskets that were recommended in the tech articles I read. I checked the valve covers before I re installed them. They looked straight.

 

[drsvox]

I agree w/ Ron on cork being the way to go. Were I you, I'd switch over to cork and use RTV on both surfaces. See if that stops the leaks.

Also, not sure if they'd help much but maybe consider using spreaders...?

 

[LonesomeSTX]

I have spreaders on there already. I read that the rubber Felpro gasket is what you are supposed to use that will stop the leak. I am pretty annoyed that I could have went the cheaper route and then better off.

 

[ranger]

I replaced mine with cork awhile ago and mine still leak. I have just learned to deal with it. usually change my oil before i have to add anymore.

 

[RonD]

The bolt holes in the valve cover will be bent down from past tightening, it's just thin steel, so when re-tightening they don't provide as much pressure between the holes as when new.
I would recommend straightening them, doesn't take much, but can make a world of difference.
Put something flat under the valve cover lip and tap it straight
Spreaders are OK, but if valve cover is bent it won't help.

Don't over tighten the bolts, it deforms the metal between the bolts, as said this is not a "pressure" area seal, it's just gravity pulling on the oil so a soft snug seal is fine.

The head surface the gasket seals will be straight, just make sure it is clean, run your finger over the surface to make sure, but this is a ground casting surface so stays pretty straight.
You can put a light on the exhaust manifold side and put a straight edge on valve cover seat surface to make sure there is no "dip" or deformity.

The valve cover side won't be straight, even after tapping it straight, I put sealant on the valve cover then place the gasket on it, then install it.
If the intake manifold overlaps under the valve cover you can put a dab of sealant where head and manifold surfaces meet, but just a dab.

Not sure for the 2.9l but you can get aluminum valve covers that don't bend, and look nicer

 

[LonesomeSTX]

I have done that many times to old stamped valve covers like these. I spent a fair amount of time doing just that when I had them off. But I could have made a mistake.