I have a 2003 XJ8 Sport with the AJ27 4.0 NA engine. Its a beautiful car... that I hope to be able to drive some day. I am hoping someone can point me in the right direction.

I purchased the car from a salvage yard with a low-end knock. I have the engine torn down and can see that the problem is a spun rod bearing. The bearing is completely gone and the crankshaft is seriously worn. The general consensus I get from reading the forum is that the engine is not worth rebuilding. The tensioners appear to be the updated metal version and are in tact, from what I can tell without removing the cover. I don't see any obvious scoring on the cylinder walls or cams.

I am looking for a donor car to perform an engine swap. I have read the threads on replacing a 4.0 with a 4.2 but have some questions. Since I don't have the SC and both engines use VVT, can I simply drop in a later model 4.2? Are there specific years/models that I should look for? Would anything from the 4.0 need to be reused? As I said, the heads look OK, but that bearing had to go somewhere.

 

Well, here's something to start with...JagRepair.com - Jaguar Repair Information Resource
It contains factory pdf's to TSB's along with some training videos.

Here's a couple threads to check, it does involve the 4.0, not the 4.2, but beefing up on a swap doesn't hurt....https://www.jaguarforums.com/forum/x...question-9301/ ...and... https://www.jaguarforums.com/forum/x...rebuild-97096/ (pay attention to what Plums says)

As for the engine swap, I don't have the knowledge on that and would have to review the link I gave ya. I would do a Search above on such or even an Advanced Search under the Tools tab. As for looking for a donor car or motor, check in the Marketplace above left in Member Marketplace, lotsa items for sale.

Personally, I'd take the crank down to a shop and have them mic' it to see if its toast or not...same with that rod.

 

Thanks for the information Highhorse. I'll check out those links.


As far as the crank goes, I am confident that it isn't worth saving. It has a ~1/4 inch groove worn into it on the side with the missing bearing. I found a replacement crankshaft on ebay for a couple hundred dollars and was considering going that route. That's when I found the info on the 4.2 swap.

 

Oh c'mon, that 1/4" groove is an expanded oil journal for better flow....less oil pressure, but better flow...lol

 

No micrometer necessary, my friend. I am definitely getting less friction from this cylinder!



2003 XJ8 Sport Worn Crank Journal


In one of the links you shared Disco1994 talked about getting his crank repaired for $120. I had thought it would be cost prohibitive. I'll have to make some calls.

 

Ewwww....yep, that is toast.