I picked up an 83 XJS convertible with 28,000 original miles on it. The interior and body is in near perfect condition other than the paint is crap and the vinyl top is deteriorating.
The down side is that it doesn't run. There is water (white foam) in the dipstick, so my first guess is probably a blown head gasket. These engines are prone to that, correct?
The first thing I plan to do is pull the plugs and do a compression test, then start pulling it apart, but I'd like to have a good manual as a guide. What is the easiest to get? What is the best? Anything I should know before I begin?

 

The factory manuals are the best. Paper versions come up on Ebay fairly often. CD versions are available from JDHT (Jaguar Daimler Heritage Trust) or from reputable Jaguar vendors. Counterfeit copies of the CDs are common on Ebay. If you have Vista the CD versions may not work.

The V12s (is that what you have?) are not really known for blowing head gaskets although it can and does happen. They are more known for dropping valve seats due to running too hot

The six cylinder engines are a bit more known for head gasket failures.

Cheers
DD

 

What about Chiltons manuals?
Yes, it's a V12. I'm only guessing it's a head gasket because there is water on the dipstick. It sat for awhile and won't turn over, so I figured I'd pull the plugs and put penetrating oil down the cylinders, then carefully work the motor loose after it has sat for a bit. Once I've got it free, I was going to do the compression test and see which bank is bad.
Either way I'd pull both sides as long as I'm in there. I figure it's easiest to pull off the hood for easiest access?

 

Pull the hood, yes. And you'll almost certainly need some sort of puller fixture to lift the heads off the studs. I think Motorcars LTD has them

Cheers
DD

 

A puller to remove the heads? Are they that heavy? Or are they just that difficult to get off?

 

It's not that they are so heavy. It's that the aluminum heads combined with steel studs results in so much corrosion that the heads become seized to the studs.

Some guys use a puller, others don't. Worth a try pulling them without spending any money to buy or fabricate a puller


http://www.motorcarsltd.com/HEAD_PULLER-12.html

Cheers
DD

 

Just how difficult is it to pull the entire engine? I may just bring it into my basement and rebuild it over the winter. I've rebuilt engines before, but I can't even SEE anything under the hood!

 

Hi Jamey

From what you say, you have the facilities to do engine rebuilds, so I would pull the engine out and rebuild. Either way, you have to do something with mayonnaise, (water), in the oil;the engine will soon be wrecked if this is not sorted out.

Reason you need a head puller is that like most traditional UK manufacturers, Jaguar uses head studs not bolts, so the head nuts easily come free leaving the heads to be pulled off the studs. With an open deck block, corrosion between steel stud and alloy head in the coolant "soup" means they glue themselves together. I would cost in a head-puller if I were you. Head studs are likely to be heavily corroded and in need of replacement.

Aworkshop manual is essential, and also a digital camera. Take pictures of everything before dismantling; you will find it a Godsend when reassembling. Workshop manuals never have a huge amount of detail on things like wiring and piping layouts, the phrase, "reassembly is a reverse of removal" is frequently seen !!! Can you remember ?

 

I'm actually very good at remembering this sort of stuff. I used to be the "engine guy" at a medium sized repair shop, but I really like the camera idea. My memory isn't as good as it used to be.
Thanks for the idea!

 

Pictures were a Godsend to me, but then I took 7 years to do the rebuild of my Mark 2. (1980-1987). It was film in those days too !

 

I agree, if you do not have decent repair manuals with good visuals, pictures will be your friend later on. Just be sure to take pictures step by step or in any major course changes

 

Some of the best manuals that I have come accross for these older XJ cars are;

*The guys who regularly contribute to these threads*.

Thanks for your continued support guys, you and we all know who you are.

We all appreciate it.