As this is my first repair on recently acquired '97 XJ6 (love it) - would just like to confirm in that I have the 'cap style' tensioner and that the piston, etc, under the cap is the same or the only one that is presently available?
And I know that the procedure to change it must be here somewhere...but not that I can find. So if someone would point that out please. Unless if it is just an unbolt - pull out the old and insert the new - of course paying attention not to move anything else in between.
Thanks.

 

The old 03.1-09 TSB has ALL the info you need.

bob gauff

 

OK.

The top chain tentioner with the cast arrow on it is the latest and greatest.

Replacement is simple as far as Jags go.

remove the window cover on the cam sensor, mark the tin plate to align with the window, or rotate the engine so the factory mark appears in the window, your car, your choice. I use a Texta to "dot" the tin plate. Remove that sensor. PLUG THAT HOLE, with a rag.
Cam cover off, it is your first time, so learn the system. It can be done without this step, BUT, if you get it wrong, that psition MAY fall inside the engine, and that will be funny, NOT.
Undo the 2 bolts securing the tentioner, and using a large blade screwdriver from inside the camcover CAREFULLY lever the old unit away from the cylinder head.
Fit the new unit, with NEW gasket and o/ring. The new units come in a "primed" state, which means the piston is wound compressed, which is the only way to get it into the hole. Tighten the 2 bolts carefully and EVENLY.
Once tightened, use that blade screwdriver again, and lever on that chain blade so as to "fire" that piston. It sounds daunting, IT IS NOT, you will feel it fire, trust me.
Refit teh camcover, and sensor, ensuring the mark you used for removal is visible inside that window.
Start the engine. It may RATTLE at first start, NORMAL, as oil pressure arrives it shuts up, about 2 seconds tops.
Check it for leaks etc, and enjoy.

Some do not "pre-fire" that tentioner, again your choice, but the horrendous rattle until the whipping of the chain actually fires it still scares the hell out me, so I do it my way.

Or, as Bob just posted.

 

Thanks to you both. I actually had come across that procedure but wanted to make sure - have changed a similar looking tensioner on a 560SL and was hoping it would be that easy....

 

If I can get your attention for another minute - so it appears that I do have the new style tensioner already installed - and don't mind replacing it...but in reading the TSB above, I do not actually have any chain rattle right after the engine starts (and runs fine). My concern is when the engine is turning over it sounds kind of loud and abrasive.
I guess by replacing the tensioner I will find out if that's the cause, or do they all sound kind of noisy on starter/flywheel engagement?

 

Mmmmmmmm.

Some report the AJ16 starter as kinda raspy, mine is NOT.

BUT, mine fires within a single rotation of the engine, cold or hot, so the starter does very little rotational work. It used to crank significantly, until I retimed the cam angle sensor, what a difference.

I am reading a lot of starter motor issues with cars in teh USA, so maybe it is your issue.

Those modified tentioners do fail, mine did, and the new one did little for my noises, so the timing cover came off, and ALL the blades/guides etc were replaced, quiet as expected now.

 

Got it. Will figure out my next move and let you know if anything definitive turns up.
Thanks again.