i have a friend selling her 85 XJS .. it has sat now for about 4 years .. new rebuilt transmission when parked no rust at all nice interior. She was driving back from shopping when dark smoke came outorf exhaust and loss of power with overheat no symptoms before she limped home replenishing water every mile or so and had car towed to where it is now . she says it will start fine but idle roughly .. i thing it can be bought for under $500.00 from her . I am a pretty good mechanic ( I keep an 85 Alfa 2.0 liter Running) and can trouble shoot l jet systems pretty well . but the v 12 is a bit more complex she says she thinks that she may have cracked a head but that was diagnosis from local chevy mechanics based on her description of failure . any thought of what i may be getting into ? I will be able to look at car in about two weeks but would like to know what to look for

Submitted by bonnettoboot@e… on Sun, 09/04/2011 - 10:53

The dark smoke, and the lack of overheating suggests a fuel problem. Have you checked the engine oil level? do so and smell it to see if it is contaminated with gasoline!

Submitted by dougdwyer1@com… on Sun, 09/04/2011 - 00:52

The engine is just the beginning. I can virtually guarantee that a 26 year old XJS is gonna need LOTS of other repairs...even more so after sitting for four years.

The Jag V12 will tolerate just about anything except overheating. My gut feeling is taht this one is "hurt". Listening to it run, a compression test, hydro-carbon test would confirm.

You can probably go out and buy a very nice condition XJS, in *good running condition*, for less money than you'll spend bring this car back from the dead.

OTOH If you like to tinker and have a big chunk of money, go for it ! There's a lot of satisfaction in a good project.

Cheers
DD

Submitted by browder@nuventrs.com on Sat, 09/03/2011 - 10:59

You likely are talking about a lot of time and money with that V12, none of those symptoms that you describe sound good, so I know that I will upset the purists, but get a conversion kit from John's and slap a nice reliable small block Chevy V8 in that puppy and you will have a nice driver for less money than pouring $$$$ into a V12.... I know, I have one ;-)