I have an opportunity to buy a 1998 XK8 for a fraction of it's book value but............it needs an engine (tensioner disaster). The seller has indicated he will include a 3.9 V8 from a 2002 Lincoln LS to replace the Jaguar 4 litre unit. It appears that a 3.9 V8 from a Lincoln LS is basically the same engine.

This may sound stupid, and will drive the purists crazy. Although the car is solid and looks great, it isn't worth the thousands of dollars required to replace the Jaguar engine. In this regard, has anyone ever installed a Lincoln LS engine into an XK8? If so, is it a relatively simple procedure assuming the engine control unit from the Lincoln is included? I realize the traction control and stability systems would probably never interchange with another engine management control unit but it would seem the swap should work.

 

I can't comment on the viability of this engine swap but I can give you my advice.

DON"T DO IT!


It it was financially viable the present owner would do it.

If it was a reasonable thing to do the previous owner would have done it.

Unless you have specific written instructions on how to do it you can drive yourself crazy dealing with dozens of small but critical unforeseen problems.

I tell you this as one who has re engined 2 Jags in the past. I had the benefit of professional manuals written by those who had previously sorted out all the problems. I was then an advanced amateur in the automotive arts and it was fun but never financially practical.

 

I've heard of someone doing the Lincoln swap, but no specific details. I bet it will be a headache, and you will lose power with the swap also. A better swap (if you don't want to use a replacement Jaguar V8) is a Chevy LS series motor with one of the swap kits that is available.

 

Purist has nothing to do with it, you might as well replace the car now as to try to put this engine in it, you will save money and time. Nothing matches up with these, they are not even the same engine mounts. If you have a racing and machine shop, you might be able to make it work eventually. I suggest finding a good used engine from a similar car, they are out there. Some of the Techs that post here know where they are. These engines are so integrated, nothing will get them straight with a foreign engine sitting in there. The tranny will never shift, the instruments will be haywire, the fuel system will just laugh when you turn the key and so on.

 

The only suitable donor here is a similar year XJ8, (which doesn't hold its value nearly as well, AND there seem to be plenty of neglected examples out there for cheap).

Other than that, LS swap it.

Rake care,

George

 

Sounds like a nightmare so I will look into the chevy option. Had a couple of XJ models with conversions and they were sweet running cars with no issues. Driving an XJ from the early eighties was always a gamble but Chevy power made them much more reliable and stronger too.

 

Early 80's electrics in the XJ's were straightforward with none of the engine management and network issues of the model you're now considering.

Graham