Hi all, I’m trying to find out some information on engine and gearbox numbers. Specifically for a 1996 XJR6 (X300). So, the venerable four litre in-line six cylinder.

Engine numbers, were these always 3 letters then 5 numbers then 2 letters?

Gearbox numbers, were these always a string of 7 numbers, no letters?

Thanks.

 

see the bottom line on this TSB

http://jagrepair.com/images/TSB/X300...%20Changes.pdf

 

Apologies for being dense Parker 7 but does this mean that something like 9JPFNB133653 is a typical engine number for X300 (supercharged and otherwise) cars from this period?

 

The number should be stamped in the area of the power steering pump coupler

The major changes in the engine during production would be the camshaft change and the valve chain tensioner change with the upgraded having a big arrow cast into the assembly and ECU Eprom upgrade with a new EGR if equipped on you country version

See these TBSs as the 2nd and 3rd beyond the 1st in the previous post

The throttle cable return spring can be repositioned to make up for not having the upgraded return spring and some have added a external spring to aid the original spring in its original preloaded position

This becomes important in the idle engine speed smoothness besides the upgraded cam

http://jagrepair.com/images/TSB/X300...all%20R493.pdf

http://jagrepair.com/images/TSB/X300...er%20Start.pdf

Your 96 may already have these incorporated

The supercharged engine may have a different cam and the numbers stamped in the cam are not a part # but a casting # before machining