Well, I got the new tensioners, bolts and gasket set and a couple of universal sockets from Sears and started the tie wrap replacement process on my 99 XK8. Had a hell of a time getting the valve covers off until I discovered the two black bolts in the middle (oops). Whilst turning over the engine with a socket on the damper bolt, I noticed that the flats on the right bank cams are noticeably displaced from each other. The car runs fine although seemingly down on power. The chain on that side can be lifted clear of the tensioner shoe!
Question is: can I just realign the flats by moving the cam itself since it appears to be about one tooth difference?

 

When I did mine the timing chain was fairly slack over the new tensioners. Its been running fine that said.

https://www.jaguarforums.com/forum/x...e2/#post571345

 

Are both upper and lower tensioner shoes plastic or metal? If is metal, the plastic glider has broken off and could be a factor in the displacement.

If you were truly off by a tooth, your idle likely would be very rough.

 

I don't know what state your old tensioners are in, but it sounds as if they were about to go away on you and the secondary chain on that bank has jumped a tooth, as you say. One more tooth and you would have a dead engine, most likely.

When you get this job finished, the two cam flats must be perfectly aligned, so yes, adjust as needed. This is very important to get right, so if you doubt your abilities, get a pro.

The tensioners do rise a bit when the engine is on...the oil pressure forces this rise but when the car is stopped there can be a bit more slack. Perhaps if you posted a short video of just how much slack is there (after you install the new tensioners and align the cams), we can be of more help to you.

Good luck.


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If I understand your problem correctly, the following should correct it (if it's a Exhaust Cam that is mis-aligned).

You should find a Crankshaft Position where 3 Cam Flats are parallel to the adjacent Head Surface.

Then the Cam that is one tooth off should be obvious, probably a Exhaust Cam.

Remember which Cam is off and which way it must be Rotated (by 1 Tooth) to be back in alignment.

Then rotate the Crank to a position that removes the Valve Spring Tension from the mis-aligned Cam.

Temporarily. tie the Zip Tie to the Cam and Chain.

Remove the Cam Caps and lift the Cam to permit Tensioner Replacement. Replace Tensioner.

Then cut the Zip Tie and rotate the mis-aligned cam one tooth to correct the position as noted above.

Replace the Cam Caps and rotate the Crank and all 4 Cam Flats should be able to be Aligned.

 

The right side is not perfectly aligned after correct alignment and chain tension locked down. The right side flats will each be tilted a few degrees to the center due to valve spring pressure. The left side will be more nearly aligned.

 

Neat trick!