I have a 97 XK8 with 74K miles that I just bought about a month ago. After reading all the scary stories about poorly designed 1st generation tensioners breaking and demolitioning my engine, I decided to change the tensioners. Today I changed the right side with minimal trouble. The only problem I had was removing that back lower cam cover screw but with the right tools and much swearing, I finally got the new 3rd generation tensioner installed. I buttoned it back up and started the engine and, to my delight it seems to run smoothly. I too can hear the timing chains running but everything seems OK.

As for the condition of the right side tensioner, it is really dark brownish red and is in great condition except for some very light cracking at the slot, as other folks have found. It has a "96JV 6B209 AC" molded into the main body so I assume it is the original 1st generation design. My peace of mine is already enormous.

Tomorrow I plan on doing the left bank. All the instructions I have read say that I have to drain the coolant before taking off the left side cam cover. I have not been able to find the drain point on the lower right side of the radiator. I jacked up the right front side and crawled under the right front of the car but don't see anything that looks like a drain. Can anyone help me? Are there any alternative ways to lower the coolant so I can safely remove the cam cover?

I didn't pay much for this car but so far I've put in the pressure relief valve for the top problem, bought a replacement CD player for the trunk, bought new front brake pads, and had the rear view mirror repaired, hopefully the end is in sight.
Help will be appreciated.

 

You do not need to drain the coolant. Just unbolt the overflow tank, leave the hoses connected, and push it aside to get access to the cam cover bolts.

 

Thank you thank you thank you. Moving the overflow tank off to the side looks like 5 minutes with a Torx wrench. My oil dip stick is not connected to the cam cover so that's another potential problem eliminated.

Bob

 

You might also have to move the small pump next to the coolant tank. I found that I did not need to remove the dip stick tube either, just pulled the dipstick out as the handle was in the way.

 

I just finished the driver side secondary tensioner replacement. It was easier to do than I thought it was going to be. I couldn't be sure that I had put the cam caps back in their proper places so before starting the engine I took off the cam cover and checked and all was OK. Those lower cam cover bolts are a PITA to remove and reinstall, especially the back lower one! I used a 1/4" knuckle adapter and even then it was difficult. Also found that the new gaskets installed relatively easy once you realize that the special ends of the bolts go through the gasket and hold the gasket in place. The same goes for the spark plug gaskets. All gaskets should be mounted on the cover and then the cover is positioned on the engine bank.

BTW, close inspection of the 1st generation tensioners that were removed were in great condition with only a very small crack in the slot area, like maybe 2 mm long. I also noticed a little raised plastic around the slot by the cracks but nothing significant. These tensioners had 75K miles on them and they looked good for another 75K. The color on both of them was a chocolate brown. Since I am never going to use them again I decided to do some exploratory surgery on them. I drilled a 1/4" hole into the plastic in between the mounting bolt holes. I found that the dark brown color is only about 1.5 mm thick. Below that it is a a light beige Nylon color. Both tensioners showed the same depth color penetration. I'm really not sure that I know the details of the maintenance history of this car but the seller told me that it has always used Mobil 1 oil and I do have the receipts for the last 4 oil changes. Considering the 12 hours I spent changing these bad boys, if I had known the condition of the original tensioners I probably would have just driven the car instead of being afraid to even start it up. Hopefully the new tensioners will survive the next 75K. Time will tell. Next project is getting the front wheel bearing replaced and putting on the front brake pads.
Oh how I love British cars, 2 hours under them for every 2 hours in them. At least they don't have Lucas ignition systems but that's another story.

 

It was worth doing.

It sounds as if your car was better cared for than many, but there is no way to know how quickly those cracks will grow and eventually cause the tensioner to fall apart.