Blew up the motor in my 2000 XJR. Have zero compression in one cylinder. I don't think the expense of a rebuild is worth it compared to what the car is worth.
The one thing that I of course though of was a 350 swap, and was wondering from those who have done it what sort of cost I might expect going that route.

You need to talk to Andrew and Jaguar Specialties as he has kits to make it much easier and will guide you in the process. PS. you do NOT want an old school 350, what you want is a modern General Motors LS V8. An LS is modern fuel injection, great power, light weight, good mileage. If you ever put a old school 350 it will decrease the value to a very low level, whereas a LS swap will increase your car's value.


Andrew Andrew@jaguarspecialties.com
(408) 839-5569
P.O. Box 320957
Los Gatos CA 95032
United States of America

I could be wrong, but I doubt the cost of buying and installing a new engine, with all of the necessary extras (new transmission, custom mounts, driveshaft, electronics, tuning, etc.) is going to be cheaper than just taking apart the stock engine and replacing some parts. Neither option is fun, but I think repairing the stock engine is the lesser of two evils.

Your first task should be determining the exact issue with your stock engine. Might be worth buying a cheap bore cam that you can snake down into the spark plug hole. That way you can get a look inside the cylinder without taking anything (major) apart.

A modern LS in an XJR will INCREASE the cars value??? er, no, I think not. Nice try though. Fix the car. It's a Jaguar XJR not a Camaro. By the time you plow through all the stuff it takes to "properly" convert it you could have picked up a used 4.0 or fixed the one you have or taken the money and bought something else to drive.

Just looked at your other thread and you say the car overheated and has 0psi on one cyl, yet you didn't check the other side. Could very well be a head gasket on the 0psi side after the overheat. I would much rather change out a head gasket then attempt a complete drivetrain swap.

The conversion kit is about $2K. The donor LS1 engine/transmission is $2-4K. Then there is the labor. Fun project, not an economical one. Rebuild your engine. Even if you pay for it and don't do it yourself it's probably 1/2 the cost.

Swap kit is a joke, LS stuff not so cheap, tons of incidentals, and a profound comprehension of the X308 wiring and LSX wiring required if you want to execute a swap with more grace that some "suggestions" from a manual.

A lot of my LS swap is riding on principle and pride, not sense. It's the way of man!

I'm sorry to hear about your engine woes, I know you've not had the car that long too. I would go with another XJR engine personally, but before you put it in the car and whilst you have easy access to it take the opportunity to address all the problems the engine can suffer. That's what I did with my 4.0 N/A engine, and it's survived two cars now and is sat on a pallet waiting to run again. It's bombproof.

Hopefully it was just the weak orginal head gasket. it's not so big issue that you have to change the whole engine. The same has happened to many others. It's time to go for 4.2 style MLS gaskets.

+1
If I were buying an x308 now and had the choice for the same price between an oe engine and an LS it would be an easy hands down decision for the oe. The other screams new batch of headaches to me, as if this car didn't already have enough mechanical/electrical challenges...

I've never heard of any modifications that actually add value to a car. I wish it were true, my $9k suabru would be worth $30 grand if that were the case.
I always laugh at craigslist listing for cars that are way over book because they thing the modifications they've done increase the value of the car.

Yeah, I was just curious of the cost as I new it was an option.
I'm back at it again I'm going to see if I can't figure out what is wrong. I've drained the oil and there was no coolant in it, an no metal filings either which is good news for the bottom end. Perhaps a valve is stuck open?

I drained the oil and there was no coolant in it, it could still be the head gasket but I'm not so sure now. Perhaps a valve is stuck open. I'm going to pull the head and see what I find.

Yeah its probably not cost effect for the LS swap, like I said I was just curious as to what it might cost. I thing a rebuild is out of the question too, I image that would probably be in the neighborhood of $5k, I only paid $4k for the car so not worth it either.

Wanna sell me that bombproof engine? how much? lol

Not so sure its the head gasket, not coolant in the oil. I know that doesn't mean its not the head gasket, it could have broken not near a coolant passage, I'm thinking a valve could be stuck open. Still playing with it to try and see if I can find out anything.

Gentlemen .... thanks for walking Mr OUScooby out of that plan. I have a little Jag driver but I am a also Vette person, the actual thing I found interesting was that they even make a conversion kit for such a thing. We are talking two different engine types and more importantly performance types. Both are great cars but the difference between any L series and AJ series is like noon and midnight.

I grew up building cars in the sixties with the model "any engine in any car" , but in this case not so much. If I pop the hood on my Corvette and look at the suspension and look at the precision of a Jag suspension they are not meant to date in public.

Think of the weight difference, think of the torque vs hp curves, I am at 1760 rpm at 75 mph, Vettes are all torque low rpm engines. Each type car is a work of mechanical art built on totally different design philosophy.

I think the original question was will a small block chevy engine (before it moved to the L series discussion) work correctly as a retrofit in an XJR. My humble opinion is no.

To address the problem at hand the first thing one would need to know is why is one cylinder showing 0 compression. It does not take a lot of lost clearance on an exhaust valve to get zero compression. If it is not a turbo, it could be a problem with the VVT, could be a retainer clip on a spring.. on and on are the options. My simple suggestion is to take the valve cover off and look at the cylinder that is the problem. This could, and hopefully is, nothing more than a head job.

Best to all

XJR's don't have Variable Valve Timing. That's an easy one to rule out. 😉. Here's hoping you find something obvious!

I couldn't sell you my engine scooby, the postage to the USA would be crazy! :P
But I'm saving it for future endeavours anyway, it's a special engine.
Yours really could just be a head gasket failure, make sure you use OEM+ stuff when putting it back together though. I used pattern part valve cover seals once and they leaked like crazy, fitted OEM and they were fine.

eBay a used engine with lower miles and install it... Way cheaper in the end