I had to replace a head on my 2000 XK8. The prior owner never changed the oil and the cam shaft spun due to sludge. Car only has 43K miles.

We have removed both heads. Both the heads on my car have a code which ends in AD (I think the code is XR830C0 -AD. I forgot to write the code down at the mechanic's shop). However, the new head we located has the same exact code but ends with AE, and not AD. Does anyone know what these codes mean and if I can use the head with the AE code on my car. Thanks.

Ken

 

p/n XR83-6C064-AD or AE

AE is just later version, virtually identical

no problem to replace AD with AE

 

All 4.0 V8 heads are interchangeable except for the intake cams (AJ26, AJ27, AJ28 all have a different number of cam position sensor reluctors) and the Supercharged heads need to have the VVT oil supply hole sealed. The AJ27 and AJ28 are supposed to have different (lighter) tappets but just be sure to adjust the cam/tappet clearance if you swap intake cams. I sold an AJ28 (2000MY S-Type) head (minus the intake cam) to a guy on eBay to repair a 1998 XJ8 (AJ26), he just reused the intake cam for the 1998 XJ8 and adjusted the valves. He called to tell me the engine ran great and he thanked me for the head and other info I provided.

By the way there is a TSB for new heads from Jaguar. They are shipped without the VVT hole drilled so they can be used on SC engines without modification. A guy in the Jag shop where I worked did not get the TSB (or didn't read it) and installed a NEW head on a Normally Aspirated engine and it had sever VVT faults when he started the engine. He had to tear the front cover and VVT control housing off to drill the hole out.

bob gauff

 

What Bob said is mostly true except that right side heads are not interchangeable between AJ26 and AJ27 as the AJ26 head has no provision for a cam sensor, which is needed on the AJ27,

John

 

John,

Welcome to the forum!

While I have not been unfortunate enough to need to replace heads it would appear that you have been there or are a tech. Hope you hang around to help others.

tp

 

thanx, TP

I'm a master ase tech been working at an independent jag shop for 4 years.

I just replaced a head on an 01 coupe that I picked up from a customer who didn't heed our warning about tensioners. 2 valves into a piston and 1 destroyed head. BTW, the p/n I gave is for left head, right head is XR83-6090-AD(E)

 

Thanks guys. Much appreciated. Still cannot believe the prior owner never changed the oil. And he was the original owner.

 

Very good info guys!

 

Thanks beauregard, I forgot about the 'A' Bank sensor not being installed in the AJ26. I have several blanking plugs for the CMPS that is not installed in the head used on the early cars. I think I removed them from NEW or REMAN jaguar AJ27 or AJ28 heads that were to be installed.

bob gauff