Thanks for the help, just a few questions.
A few years ago i bought a 2000 XJR and never even heard of the timing chain tensioner issue. My car always has clean oil and i dont know how i can check to see if has been replaced, im at 70,000 miles now. Does anyone have an XJR with more miles without secondary timing tensioner issues?
Thanks!!

 

All? Probably not... but a good percentage of the plastic secondary tensioners have failed - and with the results having a high chance of being catastrophic, it's just a good idea to replace them as soon as possible.

To check if they have already been replaced requires removing the valve covers.

 

Gonna take a stab at this one...no one can predict if all tensioners will fail, but I would wager for it in Vegas. Now when?, well can't tell. I do know that plastic heats up, cracks, and pieces fall off. Timing chain slips, valves get bent, and other bad things happen.

For piece of mind, most owners will do the change, either themselves with some knowledgable DIY instructions found in these forums and with the right tools.

You can check yours also by pulling the valve covers on each side ...they're in plain sight I've been told.

I took statistics in college, and we all know that there will be outliers on data sets. In this case, there will be some that don't ever fail, some will fail at an early mileage, while most will fall within this certain 'value'.

 

Even though Ive always had horseshoes, i think i will take the time and pull off the valve covers to sneak a peak..Thanks for the help!

 

so, which years have plastic tensioners? Or do they all fail.
Alfred

 

Theres a few posts by testpoint (might try a advanced search on 'tensioners') where he listed the model year breaks for the various 'styles' of the tensioner.

 

The change over was in the middle of 2001 engine builds - if you're well outside this, one way or the other, you will be either ok, or not. You have to look at the engine number (not the VIN) to tell for sure, if you're close.

Quoting Test Point:

"The conversion to metal tensioners occurred supposedly at the start of '02 model production but that is not absolutely true. The conversion date was August 13, 2001 at the engine plant. Since the engine serial number encodes its production date the first upgraded engines had a serial number of 010813hhmm. The 'hhmm' has not been reliably reported."

 

Hi there

FYI

I have just replaced the A Bank valve cover seals on an XJ8 engine (48,868 miles) manufactured 13 February 2002 and it has metal bodied tensioners and an upgraded primary chain and sprockets

 

Which is certainly one point of confirmation for Test Point's statement. Thanks.

 

Thats good news, i might be lucky then!

 

If you have a 2000 m/y, it DID have the plastic tensioners originally... you will be lucky if they have already been replaced.

 

The tensioners never fail prematurely; they always fail right on time.

 

And usually when least convenieint.

 

The key point is that if they fail, the engine will be wrecked, so it's always better to replace them. At least check to see what you have in there if there is no record of replacement. This will cost a lot less than a new engine. Also note that when they fail the engine is seconds away from disaster., you don't have a week of rattling to warn you.

 

OK... sorry to bump an old thread but I'm a newbie and I just want to make sure I'm in the clear. I just bought a 2003 XK8 with 71,000 miles. Since it's a 2003 can I assume that this engine should not have a problem with broken tensioners? My wife and I are going on a two-week road trip in a couple of months and I'd hate to end up with a trashed engine three days into the trip. Especially when the problem could have been easily prevented.

 

03 has the newer design secondary tensioners. See post #7 in this thread.

 

Seriously, or tongue in cheek?

I have the '98 VdP and need to get the tensioners changed out. There is only 35k on the car and it hums along like a dream. I heard from one mechanic that they don't fail until ~50k, but the other mechanic at the shop said do it now, preventively.

So... best I just suck this up and get it done? The car is a real peach...


Joolz

 

Do you want a 35k cream puff or a 40k pile going to the junkyard? It may not happen till above 50k... but it CAN occur sooner. Preventative maintenance is ALWAYS cheaper than the alternative.

 

Replacing the two top tensioners is a reasonably cheap and easy job. An engine rebuild after tensioner failure will cost a lot of money. At your lower mileage you dont have to worry too much about the lower tensioners and chain slippers. These seem to last much longer, and thank goodness !! because replacing these is much more expensive.

 

My engine had 80000 miles when I got it. The engine ran smooth with no rattling noise. Upon inspection the tensioners looked fine. I decided that I already had the valve covers off and would change them out. I bought the tensioners and gaskets in a set and rented the tools for the job from Continental Imports. $340 parts, $50 tool rental. I wasn't comfortable with the cam removal method. The right tensioner had a half inch crack and the left had a one inch crack and fell apart upon removal. Be sure to stuff some rags in the cover to catch any parts that might fall into it. The water pump may also become an issue. I replaced mine with the upgraded pump with metal vanes. Easy job but a little messy. After I returned the tools to Continental I used the deposit to get the pump. Good service from these guys and quick response. They also will answer questions that you have during the job.