New valve cover gaskets and still leaking V6 4.3

[Lou C]

Ayuh,..... Coat the bolt threads with perfect seal,.....

Yep I did that too. Got a couple spare 4.3 intakes in my garage in case the original rots out under the thermostat. Still solid when I checked last time I changed the stat. Salt water never forgets

 

[Scott06]

Youre running hard your engine! I do max 3000
How about this leak at the intake Maybe??

I think u like to work on it more than use it

Over 3000 rpms all oil leaks seal up …

 

[Kubaat3lover]

Rear portside is moist with oil When touching… any ideas? Remove and silicone seal and check If its straight ?

 

[Lou C]

Have you determined if it’s coming from the intake or valve cover gaskets. Believe it or not I’ve never had a leak from either on mine but the valve covers (tin not plastic) and intake gaskets are different on the older pre Vortec models. I’m wondering if the sealing surface of the plastic ones can warp from heat….

 

[Scott06]

Rear portside is moist with oil When touching… any ideas? Remove and silicone seal and check If its straight ?

Take it off put rtv on both side of gasket and reinstall is cover cracked ? Are u using new seals on bolts in center of valve cover

 

[Kubaat3lover]

It’s difficult To determine if it’s from intake but from port side 99.999% it’s from valve covers .
Yes both seals and gaskets are new. Seals under bolts are dry, I will use talc to check intake on the steer side

 

[Kubaat3lover]

It was OK before but after tightening the bolt I can see seeping around it…. Loosened but still… could the seal be damaged? Come on I just turned 1/4 turn

 

[Scott Danforth]

I think you are chasing blowby coming out the breather

 

[Kubaat3lover]

Still chasing the leak, more on the starboard, less on port but still visible…. I will try chalk and the engine to find it

 

[Scott06]

I think you are chasing blowby coming out the breather

Agreed, a light coating of oil keeps corrosion at bay…

 

[Kubaat3lover]

Agree I like use fogging oil for that but if I’ve got oil drip and dirty bilge and dirty water there that’s something I like to fix ..

 

[Lou C]

Just wait till the steering actuator decides to leak. Now, THATS A MESS!!!
My old 4.3 really doesn’t leak oil surprisingly.

 

[Kubaat3lover]

Lucky You…. Oldie goldie!!

 

[Kubaat3lover]

Good old school trick with talk shows it’s manifolds… I forgot my inch sockets to retorque but already ordered new gaskets …

 

[Kubaat3lover]

Hi again short update, spent whole day chasing the leak… and it’s from the valve cover…. I don’t know why, retorqueing and still same… it’s leaking when 3000rpms and more, especially WOT…
When replacing I just cleaned with scotch pad to smooth the surface…
Any ideas? Check the covers on the glass flat surface ?

 

[Lou C]

That’s a good way to tell if they are warped.
Question for those more experienced than I, can you change the plastic ones for the old style tin covers? Mine have NEVER leaked!

 

[Scott06]

Any ideas? Check the covers on the glass flat surface ?

Yes check for flatness. Clean them off get new gaskets. Put RTV on both sides of the gaskets/around bolts and snug them down. Let the RTV set up overnight

 

[alldodge]

Ya know if your return oil galleys in the head are partially clogged could be another issue. Why it doesn't leak until your at high rpm

With cover off use something and probe them in the corners. There open and just drain back to the pan

 

[Kubaat3lover]

Can I reuse my gaskets? I’m not from US and it take a while for me to import it from US. This Fel-Pros are quite new…
@Scott06 , RTV around head bolts you mean on the rubber grommet?

@alldodge , you mean to clean this oil galleys? Where are they? Do you have a picture ?

Last winter when changin oil I’ve used engine oil additive to flush the engine, I use it in my cars from time to time to keep engine clean. Now my oil is so fresh but maybe some gunk clogged it? Thanks for the response guys !

 

[alldodge]

Yes you can reuse the gasket, might use some acetone to clean the oil off before applying RTV

The drains are in bottom corners of the head (left and right) on the exhaust manifold sides. Search GM head drain holes, pics will show up