Happy holidays to all.

Im an Jaguar N00b helping a friend with a blown 99XK8 engine.

Looking for a replacement engine for an 99 XK8 i stumbled on an add for an 99 XJ8 engine with low miles! The donor car was close by & was rear ended with 27K original miles. Started right up & ran smoooth!

The owner had opted to part her out & wanted way below market asking price but wanted to wrap things up on the spot! I found & called an independent jag service shop right there & then & the3 tech said the engines were indeed compatible but a few things will have to be swapped around. Cannot find the tech in question as i dialed a random "jag service" operator provided #!

I purchased & have installed the engine already. I used the XK8 engine harness, intake, throttle body & coil packs. Im stumped on the VVT location issues (on the XK8 engine they are located on the valve covers & on the front engine cover on the XJ8 engine), the 2 plugs on the original wiring harness by the oil filter & only 1 connecter for them on the new engine!

Any help is greatly appreciated.

 

AFAIK The Valve Cover Connected VVTs are continuously variable.

The Front Cover Connected VVTs are a 2-Stage design.

The Electrical Signal is different for the 2 Designs. IE, a different ECM for each.

 

Your '99 XK8 engine is an AJ27 while the XJ8 engine you describe is the AJ26 version although I thought the '99 XJ had the AJ27 engine (the 26 had the VVT valve on the front cover, the 27 has them on the top of the valve covers). The short blocks are indeed direct swaps but there are lots of things different but the swap is still doable. The bad news is that the flex plate is going to have to be swapped.

There are several threads on the issues involved. Paste

AJ26 AJ27 swap

into the 'search' box above for more information than you ever wanted to know and wish you had a couple days ago.