3.6 - Head Gaskets ( Chris Burdo,  March 25, 2004 )

From Tom Carson, 2004-03-25

If you don't yet have a factory shop manual, get one before doing the job.

Remove the bonnet, making sure it already has aligning holes drilled in the hinge plates before doing so.  You use a pin in the holes to line up the hood when you reinstall it, thus regaining the current alignment.  It's extremely easy to remove the bonnet.

Be prepared for a couple of tough spots:

1) It is quite common for the upper timing chain adjuster to be stuck fast.  You need to free it up so you can release the tension on the upper chain.  Get some PB Blaster, and think about buying an adjusting tool.  The factory tool is not essential, since many others have talked about homemade versions...or cobbled together get-ups that have worked.  I bought a tool, and almost trashed it trying to get that blankety-blank adjuster to turn.  That little adjusting wheel in there is easy to trash as well.  Remain calm.  There are some pretty effective techniques for ultimately loosening the adjuster...which you will no doubt hear  about.  One good one is to get an already trashed little adjuster wheel, cut a notch in it, and use a cold chisel and hammer to tap it back and forth.

2) The head may well be stuck fast to the block and studs.  I've experienced it both ways (stuck and not stuck).  Anyway, I used a  cherry picker engine hoist to lift the head (and on the stuck head, the entire front end of the car!).  The cherry picker is very easily controlled, and no strain to you or your friends.  Less chance of dropping something heavy in the engine bay or on the fender.  For a stuck head, the neat trick was to use a bottle jack.  There's an overhanging lip on the head, as well as a surface at the base of the block.  The jack fits nicely in there and you can then ensure the head comes up using hydraulics.  Again, no drama.  It just comes up very gently.

After the head is off, then, obviously, clean everything very thoroughly and have a close look for problems.  Be careful when cleaning, to avoid scratching the exposed surfaces.  I used plenty of PB Blaster  and a regular wire wheel on my electric drill.  The goal is 100% spotless.

I installed the new head gasket without any sealant.  You'll get both opinions.  Mine has been fine for about 30,000 miles now.

You might also consider getting the head rebuilt while it's off.  As I recall, mine cost about $1,100 (7 years ago), but I needed new valve seats..which adds dramatically to the cost.  I suggest rebuilding the head because on an overhead cam engine, the head is more than half the show.  My car burns no oil, is strong, starts instantaneously.



From Paul Saltwick, 2004-03-25

The metal gasket does seal, but the surface of the
head and block must be perfect.  It is a mistake to "just"
replace a leaking metal gasket, you also need to find and fix the problem.
Also consider that the source of the leak may be the front timing cover gasket
while you are hunting. Lay the head gasket over the face of the head and
inspect the edges of the water passages, sometimes they corrode past the gasket
edge and need to be welded.  The amount of gunk built up on the back of the intake
valves will give you an idea about the condition of the valve guides. 

I would have the head measured and skimmed while it is off and
I would test the valves for leakage and adjust the valve clearances before
replacing the head. If you are using the metal gasket, you need to tell the
machinist that you need a smooth surface with no machine marks.  Then hang
the gasket by a string and spray two or three thin coats of Permatex Copper Coat spray. 

There are aftermarket composite gaskets available from Terry's, VSE, Rob Beere, etc..
They are more expensive, will alter your compression ratio and, in theory, will seal
more imperfections. I have never had a problem with a metal head gasket that was
installed correctly. 

Be careful about bending valves when handling the head, remove the cams or
loosen the caps. Rest the assembled head on three 2X4's to prevent bending
valves while setting clearances. Inspect the studs for corrosion, there should
be a special dowel stud in the second exhaust position. Replacing the studs is
always a good idea.  Your engine probably had lifting brackets and longer studs
in four positions.  Make sure the studs are fully installed and measure the
exposed thread and compare it with the acorn nut depth before torquing the head.
Follow the pattern and torque it down in three steps.