Hi everyone new here and looking for some help. I have a 1994 Jaguar XJS V12 convertible and my coolant is leaking into my oil. I am assuming my head gaskets are bad but was wondering if there is any oil cooler that could be bad or any other possible reason my coolant would leak into the other then a head gasket, cracked head, or cracked block. Any info on this would be extremely helpful. Thanks in advance.

 

Welcome to the forum Scott,

I've moved your question from General Tech Help to XJS forum. Members here with the same model will be able to help.

Please follow this link New Member Area - Intro a MUST - Jaguar Forums - Jaguar Enthusiasts Forum to the New Member Area - Intro a MUST forum and post some info about yourself and your vehicle for all members to see. In return you'll get a proper welcome and some useful advice about posting to the forum.

Graham

 

Welcome!

There is only one area, where coolant can enter your oil, and that is the engine itself. The oil cooler is an air-oil cooler rather than water-oil cooler.

Are you sure it is coolant? I mean, if you have slush on the oil filler cap, that doesn't really mean much. Are you losing coolant? There are loads of hoses it can leak from...

 

Yes im sure its coolant leaking into the oil because the coolant is empty and the oil is over full and extremely milky. The coolant isnt leaking on the ground and ive filled it with water twice.

 

You could pull the spark plugs (I know easier said than done! And I haven't even tackled a plug change yet) but that would allow you to do a compression test. I have a differential tester...you put 80psi in then on second gauge it says how many PSI the cylinder is holding. Of course the piston has to be at Top Dead Center so valves are closed for a compression test to work.

 

Bummer! That's unusal for a later 6.0L V12. If I was in you situation, I'd get a donor engine from a late V12 sedan. You can usually buy a complete running car for the price of a gasket set and the labor to change it. If there are complications, the labor could run away. With the V12 the chances of pricey complications is relatively high.

 

This is an engine out job to fix. It is allegedly just possible to remove the heads engine in, but more of a theoretical possibility than a real world one! An engine rebuild if you do the work yourself is not ruinously expensive, as it is unlikely that many parts will be needed. An under cover place to work is a must, in my view.
As a start, drain everything, remove the plugs, and find out which side of the V has the leak (ie the low compression). Then if you want to, having removed the engine from the car, you can just remove the head on that side. If you intend to keep the car, this is a great chance to clean up the engine bay, deal with any rust in its inaccessible places, refurb the front suspension and subframe, make the engine oiltight, etc etc.
Second hand 6 litre version of the V12 engine are not that easy to find, so rebuilding yours may be the best route. I would think that about 1000 USD for parts would be a fair budget, unless you have catastrophic damage to several cylinder sets, even if you have to buy a second hand liner, or have the head shaved.
Greg