XJS Oil Leaks

SHHHHH! Whisper.

I don't want to say it too loud........ but I'm one of those dreaded dealer guys.
And an information hound. Almost as bad as George. :-)

Good luck!

Steven- Thank you very much. I suspected that this was such a common problem that Jaguar had to come up with a good fix. BTW, how do you get access to Jaguar's Technical Bulletins? They sure would come in handy from time-to-time. -Gary

Edited on 2012-10-15 13:30:03

Here is the Bulletin listing the much improved laminated gaskets for the V12. These included the sump, sandwich plate, cam covers and also the oil filter adapter to block if necessary. I've seen more than a few of these cars with very minimal leakage years after the laminated gaskets were installed.
There are also other gaskets listed that you may not need. Also, some of the new [well, new back when] bolts may not be available for Jaguar any more. You should be able to find flange headed bolts somewhere at a hardware supplier if you come up short. The flanged bolts eliminate the separate serrated washer on each bolt; and they don't loosen like the originals were prone to.

One other thing to look into is the small oil pressure light switch, it's mounted at the rear of the engine just to the right of the larger oil pressure GAUGE transmitter. It can fracture and leak like a stuck pig. Of course it leaks right down the back of the engine and people ASSUME it is the sump that is leaking so bad. Granted it usually is leaking, but it's not always the worst of the leak. Many times the oil light switch is.

Good luck!

Gary before I did anything I would check that the filter is tight--

Phillip- Thanks for the advice. I generally run 20w50 Castrol oil in all my Jaguars, but I just purchased the 1990 XJS convertible a couple of weeks ago and do not know what kind of oil was being used by the previous owner. I am now suspecting some foul play on the part of the seller. He showed me where the car had been stored and even pointed out a very small oil stain on the garage floor. He claimed that the car never dripped more than a couple of drops of oil when it was driven and my own inspection did not reveal any obvious problems. However, after driving it on two long highway trips on successive weekends, the oil is just gushing out of this car in muliple locations, both up high from the covers and down low by both the pan and rear seal. When I took this car for the test drive before I bought it, I did not notice any burnt oil smell. After 500 miles at highway speed, however, the car needed a quart of oil and the burnt oil smell is over-powering. So there is an obvious issue and I suspect that I will be replacing essentially every gasket in the whole engine. That is why I am asking for advise about recent developments on how to properly seal a V12 Jaguar engine. Have any new types of seals been developed? Are there any new sealants which are more effective than the old ones available 30 years ago? I re-sealed my 1990 XJS coupe about 10 years ago with dry OEM seals, but they are now starting to fail again after only 20,000 miles of summer driving over those ten years. So if I am going to tear apart another V12 Jaguar engine, I want to know the latest and greatest tricks about putting it back together so even 20 years and 50,000 miles of driving will not re-open the seals. -Gary

Gary, the first thing that I would do is change the oil to non-synthetic 20w40, if you haven't done so. Next I would have a garage pressure wash the engine and add a florescent dye in the oil.
He will ask you to drive it for about 20 miles and return for an inspection.
You may find only one spot or you mar find several spots that need new seals/gaskets.
I understand that when Ford took over Jaguar years ago, one of the first things that they did was designed a complete new set of gaskets throughout.
Good luck.