[spydergear]

Hi All,

Tonight, I pulled my valve cover on my 1990 SPG to have a look at the timing chain, etc.

On my '85 I had to use 518 on the VC surfaces by the chain or it would leak oil. On this car, I don't really see any evidence of 518 or silicone. I'm wondering, maybe the Factory Manual's procedure to add silicone was for the older-style gasket with the separate little rubber half-moons. Much of what they tell you to do doesn't make sense with the new gasket, as you can't add silicone where there is now solid rubber.

What is the best practice here?

 

[AUSSIE900]

Best Practise would be to use a new VC gasket on refit . New gaskets can be done dry .
I only ever use 518 on them , never silicone , and i use the 518 when cheaping out and reusing the original gasket ,
Do so sparingly it really is a light smear .
if the old gasket is hard ( not supple ) or damaged in any way , replace it . If you have new one at hand ,,, Replace it .

 

[Jim Mesthene]

I use a whisper-thin coat of RTV everywhere.
I've never re-used a gasket.
They don't leak.

 

[jvanabra]

Back in the '90s a Saab mechanic friend told me he never used sealant, and I haven't since. I've not had one leak, ever. If it's a quality gasket and the VC is properly torqued, it really shouldn't be needed.

If I was doing this for pay, for customer's, I would probably follow Jim's advice, because it's easy and cheap and you don't want it coming back. For me, the concern is less about leaks and more about will it come off easily in a pinch.

 

[Jim Mesthene]

If unaided SAAB gaskets are so good, why do all the old 900s leak oil?

 

[jvanabra]

None of mine do or have. I did the '80's valve cover in 2007 when I replaced the engine with a younger 16v and it's still not leaking. My guess for Saab is the same as all the so-called leaky GM valve covers... people overtighten them and deform them. On the rare occasion I have had a c900 with a perpetually leaky valve cover, I have replaced it assuming it's deformed and solved the issue. My sample size is only 50 or 60 cars, but that seems a pretty good slice.

 

[Jim Mesthene]

SAAB suggests RTV on the V/C half-moons and in the gaps op the separation gasket, also top & bottom of timing cover and gable plate.
They didn't have as much faith as you. Later, they switched to recommending 518.
I'll take the belt and suspenders please.

 

[jvanabra]

Yep, all that is what Saab specified. I just don't do it, and don't appear to be missing anything as a result. The B2x5 motors use the same gasket and they go on dry, so it seems something in the reasoning changed.

 

[spydergear]

It is back together and it apparently does not leak. I did use a new Elring gasket and cleaned the cover. I also changed the rock-hard chain guide. This time, I used my torque wrench, after incrementally tightening all the bolts, to a final torque of 11 ft/lbs.

On my '85, as I remember, the gasket had to be stretched to fit, so probably not genuine or was a fake. I thought I was buying Elring, though. I also had a big mess of silicone to clean up with that VCG replacement.

With the SPG, I thought I might want to get back in there in the future sometime. So I did not use any sealer as suggested.
Definitely quieter, I think the guide was transferring chain noise to the valve cover.

Thanks for the suggestions, guys.