Can you do that without taking the front cover off the engine block, and just taking the valve covers off? Also, I've read where you dont even have to use the "special" lock tool, just remove the bearing caps of the exhaust cam, lift it up (good to have a second pair of hands for this to keep things at tension) and pop in a new tensioner.... Anybody done it that way?

Thanks!

 

The front cover does not need to come off for the secondaries.

The methods are discussed at length in this XK8/R group thread.

https://www.jaguarforums.com/forum/s...ad.php?t=37415

There is also a complete write up in one of the attachments in the thread of the 'remove the bearing caps method'....if you choose to go that route.

 

Thanks for the link!!!

I've been doing a bit more research and found the PDF file with the pics and full description of the process. One thing has me wondering though: at the point where you're about to install the lock tool on cam shafts, he says that if one of the shafts is "really out of allignments you may have to loosen the sprocket bolts prior to tightening the (tool) bolts all the way down so the cam is free to rotate". What wouls casue the shafts to be that much out of allignment in the first place? Secondary chain jumped? Would gettign the shafts to allign properly have adverse or positive effect on the engine?

Thanks!

 

If the chain and old secondary tensioners are not damaged the alignment with the new tensioners should be very close already. There may be some temporary misalignment due to chain slack when you replace the tensioners, since the new ones are not pressurized with oil yet.

The goal is to have the shafts properly aligned. More than one tooth misaligment will likely cause severe engine damage.

 

Before I eventually tore my engine completely down and replaced all the timing parts, I did the secondary parts only with just the cam covers off and it wasn't that hard. But I strongly recommend using the crank locking plug and the cam locking bar to get everything back in time. You really want to make sure, after getting the new parts in and the cam caps tight, that you are pulling the slack out of the chains in the proper direction and that the cams are perfectly in line with the crank locked in place before tightening down the sprockets. Though some say it can be done, it is very hard to do precisely without those tools (unless you don't mind your timing being off).

The alignments don't have to be very far off to cause rough running or worse.

There is also a tool to wind back the VVT before tightening the intake sprocket, an important step sometimes not covered in the blow-by-blow documents found online.

 

Since you guys are far more knowledgeable than I am, how much should I pay the dealer to do this?

I was talking to their last mechanic (he's not there anymore) and he said, 600 to open up the engine, and see if they are plastic; and 1500 total if they need to be replaced. its a 2000 xk8, manufactured in '99

 

Unless changed by a previous owner it is going to have the plastic tensioners.

Dealer is probably going to be $1200 plus, $800 plus at an independent. Four hours of your time if you want to do it yourself. Really a pretty simple job.