Replacing head gaskets on a 4.1 litre engine

[jlinde]

I am helping a fellow with going through things on his 86 to 90 Eldorados and Sevilles.

For the moment I am working with his 86 Eldorado Biarritz with the 4.1 litre engine.

So far I have just taken the transmission out because it slips and it is left to a trans shop.

The car has only 80000 miles on it but I am thinking of replacing the head and intake gaskets

when the engine is out. It is not leaking water so far but some oil around the intake manifold.

Normally it would be a simple procedure to take the heads off but in this case I feel very unsure

of what will happen to the liners -are they more or less loose = moving around when the heads are off.

I have the shop manual for 86 but I do not see any description of what will happen.

So I just wonder -is it it just to take the heads off and replace the gaskets and put it together again?

And no problems with the liners?

/Jan L.

[KHE]

You would need to replace the o-rings at the top and bottom of the cylinders. Removing the heads would also require removal of the rocker arms and pushrods. Once you had it back together, you would need to set the valve lash. I'm not sure how difficult that would be (if the engine had to come out) for the 4.1 that is mounted transversly as in the 1986 Eldorado. If it were a RWD car or an Eldorado/Seville up through 1985, it wouldn't be that bad of a job. EDIT: I saw the engine is out of the car so that will make accessing the rear head easier.

I would suggest replacing the intake gasket and leave the head gaskets alone - The reason being the intake gaskets are leaking slightly but the head gaskets are not. I don't like tearing into an engine when there's nothing wrong.

Use the GM Engine sealer - part no. 88861417 for the 2.65 oz. tube which is more than enough to do the front and rear of the intake. There is no direct equivalent for this product in the aftermarket. It is expensive but you will not have any leaks.

[Ranger]

When I replaced the HG's on my '83 Eldo I do not recall the cylinder liners moving at all and I did not replace the O rings at the bottom. It's been a long time, but I don't recall needing to adjust valve lash. I do recall some type of metal tab of some sort that spanned two lifters each. If you remove one bolt at a time they will break from uneven pressure. They are very brittle. Alternate one turn at a time on each bolt.

I do recall the need for RTV at the four corners of the intake manifold where it meets the heads.

[KHE]

The latest practice is to not use the rubber seals on the flat portion of the engine block - they will eventtually leak oil. Run a 3/16" bead of GM engine sealer (88861417) across the flat portions of the block where the intake interfaces - front and rear or in this cast, left and right since it is a transverse engine.

It is also advisable to use an automatic prick punch to add dimples to the manifold and the block where the sealant contacts before applying the sealant. The dimples give the sealer something to bite to so it won't be forced out over time. This will assure a leak free seal. The dimples are to be ONLY on the block (and the corresponding surfaces of the manifold where the sealer will be applied.

[KHE]

When I replaced the HG's on my '83 Eldo I do not recall the cylinder liners moving at all and I did not replace the O rings at the bottom. It's been a long time, but I don't recall needing to adjust valve lash. I do recall some type of metal tab of some sort that spanned two lifters each. If you remove one bolt at a time they will break from uneven pressure. They are very brittle. Alternate one turn at a time on each bolt.

I do recall the need for RTV at the four corners of the intake manifold where it meets the heads.

Larry,

You must have had to set the valve lash if you removed the rocker arms. The rockers and pushrods need to come out in order to remove the head.

[Ranger]

I did remove the rockers Kevin, but I don't recall doing anything more than just bolting them back down. I thought they where self adjusting, but like I said, it was many, many moons ago.