I've been advised (?) when purchasing the timing chain tensioners and guides for my 98 XK8, to purchase 3rd generation parts. Why would this be true, and what years are considered '3rd generation'? Thank you......

 

I've moved your post to the XK8/R tech section where you will get a better response.
A search of this section will also yield a wealth of tensioner information.

 

Third generation tensioners have a metal body with plastic slippers on the ends of the tensioners, versus an all plastic body. for the first and second generations. The part has been superseded, I would be surprised if you can still find the first and second generations for sale unless someone still has old stock. I think the tensioners were updated to the third generation design at some point in 2001.

These are the part numbers you need for the secondary 3rd gen tensioners:

• Left side: C2A1512
• Right side: C2A1511

Primary tensioners and chain guides:

• Chain guides: NCA1998AB
• Chain tensioner blade: NCA2025AB
• Primary chain tensioner: AJ82325

SNG Baratt sells a complete kit that has everything you would need for the timing chain job, at an eye-watering price, but it includes all the necessary gaskets, chains, guides, tensioners, and etc. I think other retailers may also sell a complete kit. The secondary tensioners are the ones that fail without warning, whereas the primaries do give an audible warning before the outright fail. If you plan on keeping the car a long time, it may be a good idea to replace everything.

 

There’s a good father and son Youtube source for our car. Link below will help ref. Your query on the secondary chain tensioners.

 

I doubt you could even buy 1st or 2nd Gen tensioners.

Here they are in order.

 

THANKS VERY MUCH for the pics. It really helps to see what the tensioners look like.

 

THANKS for the info......is there anyway to see the front of the engine to see just where these things go. Do you have a web sight for SNG Baratt?

 

I wonder why Jaguar (or any other manufacturer) would include ANY plastic in their tensioner parts. This third generation indeed has much less of it, but in my humble opinion no plastic should be part of any engine's internals....

 

You can see one here, don't procrastinate, get yours checked ASAP failure will most likely be catastrophic.

https://www.sngbarratt.com/English/#...20~2F%20XKR/11 You will get a forum discount (10%?) if you ask.




The plastic slippers are sacrificial to protect the chains.