Cometic Head Gasket

[Sick6]

I have an oil leak through my cometic head gaskets. I'm pulling the heads off (gn1's).
My options-
Install RJC gaskets (already have a set)
Reinstall Cometics with some sort of sealant (what kind?)
Install Felpros (part #?)

help me out...this is starting to suck

 

[PHANTASM]

i have never seen a head gasket leak oil.

you sure you are leaking from there and not somehwere else that is making it look like the head gasket?

 

[87we410877]

pull the intake first and re-seal that. Thats the only thing that could be leaking oil above the heads. If its the heads leaking oil you have bigger problems then gasket choice

 

[bilt2run]

Cometics , Hate them

I have said it one milllion times... cometics can leak (weap) oil. It wicks from the return at the rear of the head usually the pass side. I have had the same problem in the past and switched to RJC's with no problems

 

[BadAssGN]

I have said it one milllion times... cometics can leak (weap) oil. It wicks from the return at the rear of the head usually the pass side. I have had the same problem in the past and switched to RJC's with no problems

Some people don't realize just how smooth a surface these gaskets require....

Should be an almost mirror finish...

 

[oldtimer]

I have an oil leak through my cometic head gaskets. I'm pulling the heads off (gn1's).
My options-
Install RJC gaskets (already have a set)
Reinstall Cometics with some sort of sealant (what kind?)
Install Felpros (part #?)

help me out...this is starting to suck

Sick6 .... Go to the Stage 2 Tech Forum on this board. It's being discussed right now.

Go to the post " Head Gaskets ??? Cometics or 1007's

Some excellent info there

George

 

[Sick6]

I think I'm gonna go for the rjc's.... I already payed for them so might as well try them.

 

[hemi8]

Yes they can weep oil. I had to replace my driver's side head gasket last week because it was leaking oil, lots of oil (stock gasket, GN1's). Installed ARP head studs and Felpro 9441PT gaskets, no more leak. I pinpointed my leak by using UV light and engine oil dye.
M. Freeman
86 GN

 

[oldtimer]

Yes they can weep oil. I had to replace my driver's side head gasket last week because it was leaking oil, lots of oil (stock gasket, GN1's). Installed ARP head studs and Felpro 9441PT gaskets, no more leak. I pinpointed my leak by using UV light and engine oil dye.
M. Freeman
86 GN

Where specifically was the oil leaking from, at the joint in the heads where they meet the intake manifold end rails ?

I can't see any other place that they could leak oil to the outside of the engine.

George

 

[d0n_3d]

I just installed my cometics and I'm about ready to fire the engine for the first time in 3 months. I hope I get no surprises! I installed them dry with a cleaned and prepped surface and torqued the stud nuts 5 lb more than the usual. I heard these things can leak water but oil? Never heard that. If it leaks water then throw some GM cooling tablets in and it should stop.

 

[bilt2run]

RJC= no leaks, drips or errors

Mine leaked at the back near the firewall. They wick oil and follow the path of least resistance. I have seen some with no problems as well.

 

[slipstick]

My Cometics gaskets leak oil - both sides. This is a true statement.

 

[machinegun]

I have installed plenty of cometics and so far never had any leaking issues. However one thing I noticed in the above posts was people using Champion heads. Now I have never set up an aluminum headed gn1 with cometics, all of mine have been with iron headed engines. I actaully was not even going to use the cometics on my GN1 headed engine but the copper head gaskets.

 

[Sick6]

Where specifically was the oil leaking from, at the joint in the heads where they meet the intake manifold end rails ?

I can't see any other place that they could leak oil to the outside of the engine.

George

Think the rjc's with the silicone are gonna do the trick? I'll put some rtv on the seam after I torque the heads. Should I torque the heads to champion specs (65/75) or to rjc specs of 85

 

[Sick6]

Yes they can weep oil. I had to replace my driver's side head gasket last week because it was leaking oil, lots of oil (stock gasket, GN1's). Installed ARP head studs and Felpro 9441PT gaskets, no more leak. I pinpointed my leak by using UV light and engine oil dye.
M. Freeman
86 GN

sorry, wrong quote before

 

[3.8TransAM]

If installing Cometics on anything other than a 100% fresh engine rebuild, use Copperseal on them.

Brand new block/heads/etc, dry Cometics, sealed fine, no leaks.

Blew head gasket (ummm we'll just say lots or boost)

Reinstall dry after prepping everything carefully, leaked oil on both sides :-(

Tear down and reinstall, with everything cleaned and Copperseal sprayed on both sides, not a drop since. This also was told to me by Tom from Champion on the phone.

Also, use number two gasket maker for thread sealer it wont harden up if you let it sit for 16-24 hrs and then back the bolts off a qrtr turn to re torque them

later
Jeremy

 

[D's GN]

I installed a set of .060 cometics on my low mile stock bottom motor with GN1 aluminum heads and have no problems at all, I sprayed the gaskets with copper sealant and retorqued them once. If you intall them dry the finish on the block should be very smooth. I put in a couple of GM seal tabs just to avoid any possible leaks.