This thread is to document my secondary cam chain tensioner replacement project. The car is new to us - it is a 2000 XK8 with 70300 miles and had been kept indoors for much of its resting life. There are some records that indicate that it was well cared for. And looking at it it appears to have been taken care of. See my signature for the current project status. The goal is to make it road worthy for my wife to drive. It was her present...

In posting about the other projects folks have been telling me that I need to get to the secondary came chain tensioners first. This is of course great advice and though I did not express my understanding of the need very much , it was always on the top of my list. We had a break in the weather and as that I do not have a garage (going to build one RSN... real soon now) I took advantage to do the right side tensioner in the 4 or 5 rain free hours today. In the end I did get rained on and got most of the replacement done. Here a few photos of what I found. Of course there were a number of glitches and other problems to overcome along the way.

The three photos show the old tensioner in the car, the new in its place and the old outside of the car. Notice the huge crack along the body of the old tensioner. It was still working because of the metal sleeve internally. Who knows how much life it had left. This really illustrates the advice from the forum to not drive the car till you know you have good tensioners.

So I am half way there RE tensioners. I'll be waiting on a sunny day to get the left side. Hopefully the parts to finish off the shocks and transmission will arrive soon too!

Of course kudos to all those who have gone and done the hard work to figure out how to do this.

As a side note the local shop (Kings Cross) quoted $3000 to this work - parts and labor.

 

Its really a bummer that Jaguar failed to engineer a really good chaindrive to the cams... when looking at it it feels more like they made it as an afterthought, rather than based on good established engineering standards.. I did this job, both on secondary and primary chains on my 1998 Daimler, bought all the tools and a good kit where all the seals where included as well. It was a friday to sunday job in my garage, a quite straight forward job in my opinion.

On my 2003 Jaguar XK i have a scary rattle for roughly a second before the oil pressure is up, even though the engine is fitted with metal tensioners from factory.. so a full tensioner/chain/guides replacement is to be done this winter.. Il guess that the chains and guides gets old/stretched and somewhat worn over time regardless.. To visit all the chains after 22 years and 160000Km´s feels right.. better safe than sorry..

 

All true apart from the fact that the OP's factory fitted tensioners lasted 25 years. The third generation metal tensioners that most of us have installed by now are more robust, but how much longer would a "really good chaindrive" last? 50 years?

 

truth !

If Jaguar had engineered these cars to last 50 years they would’ve been costing twice as much. And the company would’ve folded long ago.

Z

 

In my opinion they should at least last 300 000Kms without breaking a sweat.. replace if you feel like it or else just keep going.. The ones Jaguar first came up with for their V8 engines are an engineering disaster.. The plastic parts dies du to heat and crack before any real mechanical issues.. and all four tensioners should have been made with a ratchet function since day one. And maybe they should have been a "2-row" type.. not a single bike chain..
The staggering number of engines that has bite the dust due to this single issue alone, suggests that something went really wrong when the engineers where.. well.. engineering things...

 

Just be grateful for chains. We could have cambelts. Or, even worse, wet cambelts!

 

I think you'll find zray has passed that mileage figure 25 years after his car left the factory, but you are right, Jaguar didn't engineer these cars to last.

 

Since we're engineering things here, allow me to post my $.002 on the cam chain comments. A double row of the same pin diameter and sprocket width would be too heavy and make the engine that much longer. A double row chain of smaller pin diameter would be no better and probably worse. Since each chain only handles half of the total cam load, the double row that I have on my Chevy 283 is carrying just about the same load as the single row on my XKR.
As to a ratchet function on the adjusters, you then have to be concerned about the differential thermal expansion of aluminum vs steel that would over-tighten the chain and create faster wear.
By August 11, 2001, Jaguar got it right on the cam chain design. Can we leave it at that?

 

@evm If you are not replacing the primary tensioners and chain guides, you may want to drop the oil pan and check for debris.

The primary tensioners are the same material and heat cycling affects both the tensioners and guides which crack and break up. Dropping the oil pan will give you an indication of the guide state if you find plastic fragments there. Doing so will also give you an opportunity to clean out the oil pickup.

A coat of paint on the oil pan will preserve it and your wife will have something nice and shiny to look at next time she is under the car......

 

^^ +1

 

Nice thought on the shiny oil pan. I doubt she will be under the car soon as that she is too busy driving the tractor.

I've got an oil change due when I get around to installing the TransGo valve in the transmission. I had thought to look for debris in the oil pan. Dropping it fully is a great idea.

Not sure when but I do expect to replace the water pump on the assumption it has nylon vanes. I expect to R n R the primary tensioners then. Debris in the oil pan will change the timing for sure.

Best!

 

I agree with hellcat. I dropped my pan and gave it a good clean and paint job while I attacked this job. I also agree with the advice of not waiting too long, or at best minimizing use of car until primary tensioners and guides are done. If your secondary ones were plastic and cracked, the others will undoubtedly be too. And most of all, don’t downplay the meaning of the word “debris” thinking dust sized particles that accumulated. My guides were missing chunks of plastic material and severely cracked in many places. And by chunks I mean literal pieces that were measurable in millimeters. A couple were found hanging out in the bottom of oil pan, and the bulk were stuck to and blocking the screen for the oil suction pump. My car started and ran seemingly fine, with the occasional hiccup upon starting until tensioners refilled with oil and pressurized. But I was shocked at the extent of the condition of guides and tensioners. See following photos…

 

 

Agreed. At this age, don't skip on primaries.

 

I don't want to hi-jack this thread but just would like to ask, are the primary tensioners any better on the later 4.2 engines?

Jack

 

I'll get to the primaries next spring or perhaps in the winter. We will not be driving much in the cold. But Getting the secondary's done removes a potential hand grenade.

No worries RE 4.0 vs 4.2 primaries - I am interested in the answer to that question too.

I'll just have to start studying up on primaries and water pump replacement. Pointers to quality parts are welcome.

 

that’s a broken phaser park pin, 4.2 only problem and not a big deal anyway. has nothing to do with the chain drive

 

Nice pics @stevis05 , maybe you could use them and publish the "XK8 Timing Chains - The Definitive Guide" coffee table book

 

I would love to hellcat! However I can only speak to my experience of doing so with my 97 model year xk8, which still has the original nikisil lined cylinder bores, and there are so many other members with much more knowledge than I have, of other year models and their differences who would be much more qualified than I to do
so, but I would give it my best shot!!! I might sell a copy or two, but wouldn’t want to lead anyone in the wrong direction! But thanks for the compliment!!

 

Got time today to replace the left side secondary cam chain tensioner. This side was in worse shape than the right. It has the same long crack but also has lost its shoe. With all the advise about doing the primaries I've placed their replacement on my todo list. Sometime in the spring. It is about 50 outside and with a 5000 BTU heating going I was able to get the temp up to 60 (15.5 C). Not bad actually but the various plastic pieces were more brittle than ever. I'll get back outside and run it with the ECU fuse pulled and then put it back and start it up to see if all is well.

As a side note it appears that the left side had more gunk in it than I recall for the right side. I'll have to look at the photos to see if my memory is faulty.

I thought the left side was easier to do. It was nice that I did not have to open up the coolant system, just move the expansion tank aside.