I am new so forgive my ignorance. I need to replace the engine in my 1998XJ8 and need to know what engines in AJ series are compatible. If it is feasible to replace with a 2001-2002 engine or must I stick with 1998-2000 series? Not very knowledgeable about jags, but would think their was a wider range of engine swap interchange then what I am seeing.

Thanks
Bill

 

Pretty sure anything from the X308 is compatible (98-03). In fact, that would be a better option since you'd have updated tensioners.

But, don't quote me on that. Wait for an expert to reply.

 

Hi there

I run a 1998 XJ8 4.0L (70,000 miles)

The previous owner didnt check the oil and threw a crank bearing. It now has a 2001 engine with 32,000 miles on it. It went straight in

Regards

 

You need to check if your VVT's are on the timing cover or the in the cam covers. Also, if you have 1 or 2 oil pressure sensors down by the oil filter housing. If those two areas match up, the engine will interchange. Most 98 models have the VVT's in the timing chain cover and will not interchange with the later model engines.

 

Being a noob I am having Nomenclature problems here, VVT I am guessing is Variable Valve Timing???. I am also guessing the issue centers around the 30 degree v. 48. Being a noob, I am just guessing. What is the easiest way to identify the VVT? I know this sounds bad but I have handle many engine swaps but not on a jag or such an advance engine. I was wondering if a donor vehicle including Wiring harness and ECU could be done to allow use of later model engines or would that be asking for a huge headache of a swap.(sounds like one to me) Thanks for info, It certianly has helped. Has not made me feel any better LOL! It also implies that not all 1998-2000 are compatible! yikes. Anyone sell a reasonably price overhaul kit? I might be sick lol.

Thanks
Bill

 

I'm sure Ken can sell you a good quality rebuilt engine to fit your car, and if you have that kind of money to invest then that's the best way to go.

If you choose a less expensive course, a tested and updated used engine is your next best route. You need an AJ26 engine, which limits your search to 1997-1998 XK8, and 1998 XJ8 ONLY. 1999 and later engines are not directly compatible: you can interchange a long block from the later AJ27 engine, but you'll have a significant amount of time, parts costs, and camshaft timing tools to acquirethat make this an impractical solution.

Similarly, installing a complete '99 and later engine along with the later wiring harnesses and ECM (engine controll module)is imprudent: you'd need the later ECM to control the later Variable Valve Timing system, but you might have communication problems with the '98 transmission and TCM (transmission control module). Thoseare specific to 1998 XJ8, as is the engine.

The term "rebuild kit" doesn't really apply to Jaguar V8 engines. You can't buy oversize crankshaft bearings, so a damaged crank means $1000 for a crank and bearings. If the cylinder bore lining is deteriorated or damaged, you'll have to purchase a bare sleeved block or find a machine shop to sleeve yours.

The cheapest of seven1998engines I found in Alabama is in Mobile for $2250, no mileage is listed. Get in touch with me privately if you want another option, I can deliver you a tested and updated engine for $2500 with trade. You can come to Ohio and drive it before you buy it if you want.

Blowby/ loss of compression, broken timing chains and smashed valves, overheating from failed water pumps and thermostats, and spun rod bearings are all significant concerns with these engines. Any used unit you purchase should have new secondary timing chain tensioners, water pump and thermostat replaced as a minimum. If you're lucky enough to find a super low mileage '97-'98 engine, you'll probably be paying enough money that you'll be better off where we started, buying a rebuilt from Ken.

 

Oh, it just get better and better! I need to check a few things on this one such as those mentioned on which version of AJ I have. I want get away from these nikisal liners and fix the tensioners. I looking for best alternatives even if I have to convert the complete drive train. I know cost vs. the value of the vehicle becomes the ultimate limiting factor in the end. I might have to go with a used motor sporting the same flaws. All and info welcome since it provides me a better base to make a good or sound choice. I want to th ank all that have responded so far. You have been a tremdous help.

Bill
Moulton, Alabama

 

Sorry to hear about your misfortune. With the old jags, we used to be able to drop the front suspension and change the bearings in situ, assuming things weren't too bad. I know tolerances are a lot tighter these days but has anyone given that a shot? Jag cranks are (were?) pretty stout. Would it be worth the effort?

 

I gotten a lot PM and emails which have laid out a lot options for me. Recommendations have range in the dollar amount of 1500 to 8000 and from difficult to highly difficult skill. Of course some of the lower end recommendations have qualifiers that may or may not apply.

More ground work is needed on my part. I don't have a leak down tester but I fixing to order one, need it anyway since fool with a bunch of old motors. I know that is a critical to making a proper assessment of my problems. While it has symptoms of Nikasil liner problems, it must be verified. It also shows no symptoms of excessive blowback or oil usage. I am working from worst case scenriao. I ll know more the condition of block/combustion chamber after doing a compression/leakdown test. The engine has 120k on it and if still has Gen I tensioners, I assume we have a miracle not to have jumped time already. I need to verify tensioners condition and type also. I ll get to work on my end.


I don't theorically see me spending more the 5000 to fix a vehicle whose value is not much more then that unless I plan on keeping this vehicle for a long time. Whether I want to keep the vehicle for several years or not, must be answered. I ll be discussing this with my wife over the weekend...after I get back from a hunting trip. Got to have your priorites right now . Gentleman, you have been very helpful and I thank you again. Not that I am closing the thread, any suggestion welcome still! I very gratefull for this help and any suggest or solution this community might offer.

Thank You
Bill

 

Hey there, have been on the search for recommendations and technical help with my 99 VDP. I purchased the car after my friends mother drove it till it stopped with no coolant in it. Needless to say the engine got very hot and it melted the intake manifold a bit and the two knock sensors on the top of the engine got so hot they melted and started to run. This car has only 54K on it, and I am one of those guys who really likes original cars and I would like to keep this car original with the original engine, however I am also a realist and know that the cost of making this engine right may just not be feasible. If you could offer your experience and expertise it would be greatly appreciated. I have torn the engine down to the the part where I need to remove the heads, am at the point where I am going to need the specialty tools to continue, but do not want to waste money on them if its not going to be worth it. So I guess I am asking should I bother trying to rebuild this engine first off, if not, what are my options on used engines etc and if I am going to scrap the existing engine is it worth keeping it for any parts for me or selling/exchanging for the used or rebuilt engine. Thanks for your time and expertise.

Yours in motoring,
Jeff L.

 

Our long lost friend JagtechOhio pretty well laid it out above. With the described damage to the original engine it is not only not economically feasible to rebuild the engine but if done would not be considered an original engine anyway. Both the heads and block are, most likely, toasted or more accurately, boiled. Aluminum engines just cannot stand such abuse.

Any of the normally aspired (NA) AJ27 engines in XJ8 or XK8 cars '99 through '02 should be directly swappable.

A rebuilt engine will not have any of the bolt on accessories like throttle body, sensors, starter, alternator, PS pump or AC compressor so you are going to swap all that also. It may not even have the water pump. On used engines they may or may not have all that based on price and negotiations. Of the remaining long block I would suggest that there is not going to be much of value left.

Also pointed out above, do make sure you get all the updated stuff like tensioners and steel sleeves.

 

Well thanks Test, I figured as much but just wanted some other opinions on the matter. I am on the search for an engine then. I figured that most of the accessories on the engine are in good order. I figured on all new cooling parts anyways, radiator, thermostat etc so a new water pump would not be out of order. I would rather replace these items while I have the engine outside of the car before install anyways. I would like to have an engine that has had the upgrades you have mentioned. I noticed a post from Ken at british car parts, I was going to see about contacting them about an engine. Thanks again.

 

I would do a compression test or leak down before I took the heads off. What is wrong with the motor ? 54K miles and it's trash ? Man, somebody ought to be strung up for allowing that to happen. If the bottom end is toast, you need at least a short block. If the bottom end is okay, then fix whatever is wrong with it and keep it. I'm like you in that I would rather keep the original engine. If swapping another engine in is necessary, I would want some good reason to go to that length.

 

Me too, and to find out why it cooked in the first place. Fitting new thermostat would be on the list as its cheap and leaves this part out of the equation. Does it turn over by hand?

 

Unfortunately I know exactly what happened to this motor. It was driven by the 83 year old mother of a friend of mine. She apparently continued to drive it after one of the radiator hoses had come off. She drove it until it would not drive further. The motor was very hot, the two knock sensors on the top of the motor started to melt. The plastic intake was slightly melted as well where it mates to the the head. As far as a compression test, I did do that. There is very little compression on most all the cylinders. I cannot quote you readings as it was quite a while ago that I did them. However before I even did the compression readings, I turned the motor over with the spark plugs removed and I was pleased to find out that I had not only a very nice lawn ornament but a fountain as well. Coolant sprayed out from several of the cylinders. So it seems as though at the very least the head gasket is gone. It would be nice if that were the only issue, however I am not holding my breath.

Jeff

 

Just wanted to give a heads up that I added a seperate post with info about the 99 VDP engine problem. Appreciate anyone who would like to contribute.