A friend of mine just bought a 1999 XK8 convertible. He jot a good price but no service information. He was not sure if the upper cam chain tensioners were ever changed to the third generation, metal body with plastic rub strips on the top and bottom. We just removed the right cam cover and it had the third generation. They had turned a little pink with time. I was checking the top rub strip with my fingers. That rubstrip was not firmly secure to the metal body. It looked like it was secure with the ends holding it in place.

My question is has anyone had a failure of the plastic rub strips on the third generation tensioners. I am a little concerned. I changed mine at 41,000 miles and it now has 73000 miles. His car has 72,000 miles and no info as to when they were changed.

Come on guys, give me a response. Hopefully Motor Car Man will response.

 

The wear strips on the newest tensioners are made to be loose but secure so that if they shrink with heat and time, they won't come off the metal tensioiner shoe.

 

Thanks Paul,

The top strip is definitely loose but secure around the edges to keep it from coming off the metal seat. Maybe they are like that since the metal base will expand when it gets hot. Do you know of any third generations that have failed due to this or any other problem. Trying to get a feel for the life of this design.

Thanks again.

 

I came across this post of Terry Young's the other day when I was searching for something else:
https://www.jaguarforums.com/forum/x...1/#post2089407

It's the only one I'm aware of, although it didn't kill the motor.

 

I have seen the third generation secondary tensioners fail where the plastic slider on the plunger cracks and falls off.

 

Just as important is making sure the primary timing chains, guides and tensioners have also been replaced as the plastic parts of the guides break and end up in the sump.