I purchased a 2000 S-type a couple months back and finally was able to bring it home and start working on it. When I purchased it I knew that the engine wasn't running. I posted in the past about installing a GM LS3 engine, because that is still what I want to do, but I figured I'd find out what broke first.

- The car has 92K miles on it
- 6 of the 8 cylinders have 120psi compression (spec is 140 to 150 I believe.)
- 2 cylinders have no compression: 2B and 3B. Driver side of engine, middle two cylinders)
- All of the spark plugs are very black and wet with some oil/gas smell
- Every spark plug has a little oil around the base of them. (leaky valve covers)
- No water in the oil, Oil looks clean.
- Engine still starts and runs but has very little power.
- No noise from the engine like a bad rod bearing or bent valves.

Anyone want to speculate what the problems is?

I'm betting on a blown head gasket between the 2 cylinders?

Thanks.

 

This morning I did a cylinder pressure test. Air is leaking out of 2B into 3B.

I am wondering if a head gasket failure between cylinders a common thing for Jaguar engines?

 

Get the head off and prove it! I think you've diagnosed it. In days of yore when I used to whip off heads with impunity, I always "skimmed" the head using a big sheet of new blockboard and a full sheet of fine emery cloth by pinning the emery to the board with drawing pins, the moving the head back and forth with as even pressure as poss. on the emery. Checking every few strokes you could see the minute distortions in the head surface as the new bare metal became exposed. When clear, I would then turn attention to the block top. If I could get the head studs out, I'd give the same emery attention to that. If studs were totally jammed, I'd clean up the block top as far as poss. with rags and petrol, and hard crud being scraped off with a piece of hard wood.
Reassy was then with a new gasket (being sure to have the same thickness as the original) using Blue-Hylomar on block top, both sides of gasket and head. Braces and belt if you like. Sure thing, it sounds crude, but it always worked for me!
Best wishes for a fix,
Leedsman.
(Oh, look out for bent valves too, you never know...)

 

Joe, how did the cooling system look? I'm wondering if the motor was overheated, or if there is a potentially warped or cracked head. A head gasket shouldn't be that big a deal to do.

George

 

The leakdown test should have told you, you have to find out where the air is going.

As to your question about the head gasket, not common. I'd GUESS it's more likely dropped intake valve seats from overheating. One real easy way to verify that is by checking the valve clearances. Dropped seat equals extremely large clearance.

You don't need a feeler gauge to tell the difference, you can usually do it with a 7 iron.

 

The anti-freeze in the reservoir look to be the normal yellow color with just a tinge of brown.
I have started to tear the car apart in my driveway, but the weather isn't cooperating, so I am not making fast progress. I hope to get the engine out by early next week. Then I'll be able to tear into it and see what went wrong.

Should there be a prize to whomever guesses what went wrong?

 

Of course there should be a prize Tijoe: a bag of dolly mixtures. Or Smarties even better.
Leedsman.