It has been over one year and 4k miles and still runs great, but you will have to ask my wife as she took it off me when I was finished with it. I now drive the Tundra. Jag has had no problems as of yet.
Thanks
Bill 98 XJ8 VDP

 

So, by loosening the VVT, does the intake sprocket position change relative to the intake cam? I didn't think so, but I wasn't thinking very carefully... of course, you are right.

But the bottom line is that, without this VVT adjustment (when using the tie wrap method), both sprockets are in exactly the same alignment, relative to the crank, as they were before the operation; so if performance was acceptable before, it will not change after.

 

I agree with that completely!

 

Could you recommend someone in Boston area who could do the zip tie method change of upper tensioners.

Thanks

 

To Oligarh -
I'm hoping to do mine later this summer. I'll let you know how it turns out! I don't know any actual Jaguar mechanics in this area. I have concluded that they are all frightfully expensive, so if too much goes wrong with my car, that I can't deal with myself, I will walk away from it.

 

I'll have to give that a try. Good idea!

 

If you are paying someone else to do it, it should not matter how they do it. Just how much they charge.

 

Well. I had my upper tensioners changed today. Got charged $600 total by a mechanic who was recommended by a friend. They charged me for 4.5 hours labor and parts (price negotiated down from $670.00). The tensioners were made in Japan to Jaguar specifications. I think it is a pretty good deal.

Here are the old tensioners:

http://photobucket.com/oligarh

You should be able to see the cracks more on one and less on the other. I did have an intermittent chain rattling at cold start. The mechanic said I should be set for the life of the car (my 1999 XJ8, which I bought 2 months ago, has 86000 miles).

 

Needless to say, the original tensioners were 2nd generation (dark brown/orange), but the mechanic said that they were not changed, but rather fitted at a factory starting from 1999.

 

WHITE XKR is right!

Alhough I said I agreed that the zip tie method gave the same cam position as before the disassembly, I got to thinking about what Brutal said about actually comparing the position and finding it different and what WhiteXKR said about dimensions . Today, I got around to changing the tensioners on my 98 XJR with 260,000 miles. I beleive the tensioners in it were the first generation, so I am afraid they were the originals. Wow, I guess I dodged a bullet.

Anyway, I compatred the dimensions on the 3rd gen tensioner with the ones from the car, and the location of the tight side slipper plate is at least a few millimeters different from the mount on the two. I made no effort to calculate the angle error it causes in the cam position, although I am pretty sure it is quite small, and I re-assembled it after using the zip tie method, although I have the tools.

BUT, the zip method DOES NOT exactly set the cam if the tensioners have a different dimension of the slipper shoe, as mine did.

 

Thanks for the update and clarification of WHITE's statement - it does make sense...

It IS always the fixed slipper that's in contact with the portion of the chain that's under tension between the cams, correct? (facing up or down, depending on which bank) A difference in this position will make change in effective chain length between the cams... so, I guess I'm reversing my previous statements.

Now the question becomes - how much of a difference in chain length is there, and how much change in relative cam timing does that induce?

 

Can this be true? I always thought tensioners of any sort always worked on the slack side, whether for chains, cogged belts, v-belts, or serpentines.

 

No Boomer, it is not true. I was just jerking you around!
Seriously, I agree with your point. I do not know why the Jag engineers thought they needed to put a rub plate on the tight side of such a short chain, but that is what they did . There is a unmoveable plate on the tight side and a moveable, pressure loaded plate on the slack side. I have not confirmed it, but I suspect the so called gen II tensioners, which are plastic and do crack, may be the same dimensions as the gen III available now, but at least the gen I and gen III I measured were different..