I didn’t write this for yall, as most of you guys have obviously not experienced leaking valve cover gaskets. (yet) I figured maybe some of you guys doing your swaps could save a lot of trouble for yourself down the road.
This is a “your thoughts” thread. I’m not saying this is how to do it (Tho This is what I’ve done).
(For the remainder of the thread VCG – Valve Cover Gasket. RVCG – Specifying the REAR Valve Cover Gasket, FVCG – You are a moron if you need this definition)
It’s obvious Toyota’s implementation for the v6’s doesn’t work. Blame whatever you want, but there is no arguing the fact that it simply does not work. Worse, nearly every engine has a VCG leaking to some extinct, almost EVER engine will have the RVCG leaking over time.
IMHO it’s from a culmination of two things:
1) I don’t like the groove style VCG. The flat engine’s use corker, rubber”ish”, or rubber/steel core gaskets & have less problems. Not only that, but it is advantageous in that if it is ever replaced (for any reason) you simply use a tube of gasket maker & the seal is nearly indefinite. When applied correctly, they won’t leak until you break the seal!
2) Improper valve cover gasket bolt torque. Even tho the rubber gasket provides some tension on the cylinder head bolts, the spec is 4.3-5.75ft-lb. They easily get loose, or are extremely over tightened when repaired.
3) 1 & 2 are compounded by the huge rearward angle the v6’s are tilted at.
So I’m sick of it. Sick of hearing about it. Sick of most of us considering it a “routine maintenance” item that should be replaced every time someone is going near them. “Oh well you’re getting X done, Have them do the VCG’s before they start to leak!” etc.
Here’s how I think we deal with it once & solve it for the last damn time.
Ultra Black RTV. RTV is *the* gasket “brand” of choice by everyone. Ultra Black is a premium line, and Permatex’s most oil resistant RTV gasket. Even better. It is apply & go. (Non-premium RTV’s need time to setup when mounted & some need to be re-torqued.) It could take 2 tubes. I used 1.
Thread Locker (Medium – Loc-tite & Permatex Blue)
Acetone, Paper towels, Q-tips. (Ya, ya Alcohol works, Acetone just eats oil so much faster tho! Ventilated area for both)
Scraper (or something with a flat edge you can level with)
1) Clean the gasket mating surfaces with Acetone. I find you can push paper towels through the groove, but a few Q-tips make very short work of it & you can be sure you’ve cleaned it thoroughly.
2) Completely fill the groove with RTV & scrape it flat so that it’s a flush surface.
3) Run your tap down the threads of the valve cover bolt holes. This will clean the threads up.
4) (After the RTV has cured – 24 hours) Apply your “normal” 1/4″ bead of RTV as a normal application.
5) (IMMEDIATELY) Put valve cover on & bolt it down. Since we’re no longer using a “light pressure to seal” gasket. Torque the valve covers down to say 18-20ft-lb.
Using online calculators: The stock bolt & hole threads have a Recommended Torque of 15.2 ft-lb & Maximum Torque of 20.2 ft-lb (Not freaking 4-5ft-lb!?)
I don’t think it would be wise to drill & tap for a larger size, though someone could. It’d be hard to drill large enough to have good threads, without having some huge bolt running down it. (I just don’t think there is any reason for like an M10. Those would hold 40-50ft-lb! That’s above the head gasket range!)