Why do some people not recommend RTV use on valve cover gasket?

[BoyYota]

I'm about to do my valve cover gasket set and I have differing opinions on whether or not to use silicone. I heard that it's the 'old-school' way and my brother-in-law says he doesn't use it and doesn't have any problems.

[Kiwi-Corolla]

The rubber valve cover gasket doesn't require any RTV sealant. As long as the gasket is brand new and/or in excellent condition, it will make a perfect seal. The only thing I'd suggest is that you smear a very thin layer of engine oil around the gasket before reinstalling the valve cover. You shouldn't have any problems with leakage whatsoever if the nuts are torqued correctly

[demonics12]

i just dont do anything the factory doesnt do for assembly

[speedy25]

Most people who have a tube of silicone sealer use it incorrectly! Anytime you see blobs on the outside of a gasketed area, there will be the same blobs on the inside. These blobs can go anywhere when they fall off and wreak havoc. Learn to put it on sparingly on anything that requires it.

The only time you need it on a valve cover gasket would be on the bottom of the "arch" where the cam sprocket is. Most people use none. I go either way depending on what the gasket does. Some seal well with no sealer and some need a little.

Make sure you got the WHOLE kit with the spark plug seals and cover grommets. They get hard as a rock and dont seal properly with age.

-SP

[BoyYota]

Yes speedy, I do believe I caked it on a bit much and indeed already had one of those silicone bits go in my engine. I ripped it the other day to 45 on first and shortly after the shift the car jerked and rumbled for a moment and I seriously thought the thing was busted for good. In hindsight I used a bit too much of that silicone and I think that's what it was. I was seriously concerned, and noticed the grommet rubber falling apart on the outside, but I took off the bolts today and the grommets are holding fine under the metal covers. They're already stuck good to the valve cover. I'm going to keep driving it as is and hope no more clumps of silicone get sucked through. I was planning on taking off the head and having valve work done to see if I can stop burning a quart every couple of days anyway, but not for another couple of weeks at least.

[speedy25]

Valve work wont stop the oil burning. Oil gets into the combustion chamber through-

Valve seals
Past rings
defects in PCV system, or PCV system overwhelmed by excessive blowby (rings)

You can test for ring leakage with a leakdown test. It will also tell you if you need valve seat renewal as well.

-SP

[BoyYota]

Valve seal/guide work is what I meant by valve work.

[PatrickGSR94]

I put some Permatex Ultra Grey on the corners of my 7A-FE where it goes over the distributor and camshaft. Honda calls for it on the corners only on my Integra and I've had no problems for nearly 300K miles, so I put some on the Corolla's gasket (corners only) also.