Timing Chain Tensioners, 2001 4.0 litre V8

I have a 2001 Vanden Plas with 55 thousand kilometres (about 33 thousand miles) on it. The concensus among the Jaguar mechanics I've talked to is that it is not a question of if the timing chain tensioners have to be replaced on the 4.0 liter V8 if this year, it is a question of when -- they are plastic and will fail at some point -- with catastrophic impact. Tell tale sign is a rattling noise from the front of the engine, especially upon startup. One mechanic told me that the earliest he has heard of an engine failing because of this was 72 thousand kilometres (about 42 thousand miles). I have a quote of $2200 Canadian for parts and labour to replace upper/lower chains and tensioners and the water pump, which is also destined to fail in this era Jaguar as it has a plastic impeller. I don't want to put off this repair if it is required. Any comments on this situation?

Alan Strickland Victoria BC Canada

Reply to
Alan Strickland
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Hi Alan,

That sure sounds low on mileage to need to replace the tensioners, I have a

98 XJR and got to 90k miles before mile started to sound like a bag of nails and needed both top and bottom tensioners.

You will definately start to hear when you need to replace them, so don't bother unless you are starting to get a rattle.

The advice about the water pump is good, it is well worth replacing it if the front of the engine has to come apart, which it does for the full tensioner replacement.

Make sure they replace the chains as well as the tensioners.

Cost for me in the UK with a very good independent garage was just a little over £1,000.

Regards Adrian

1998 XJR

Reply to
Adrian Higdon

I'd bear in mind that once you get the "rattle of death" replacing the tensioners is something that has to be done right away. Same thing used to happen with early Porsche 911's, if you were lucky enough to actually get the warning rattle before bad things happened. Then it was either shut it off and have it towed to the mechanic, or if you were really brave drive it there and hope for the best.

The other Alan

Reply to
wtrplnet

Get it done. Yes. If you have an 01, there is a reasonable chance you have the second generation tensioners. What Jag did was to modify the original design and added a spring to the guide shaft on the secondary. The rattle sound was caused when the oil seeped out of the tensioner and this allowed the chain to slap a bit on startup. That was the telltale sound. The second generation tensioners are every bit as weak, but won't give you the early warning. The third generation is a whole new metal design.

The problem is at startup. If the chain slips one tooth, you will get a rough running engine. If it slips 2 teeth, your engine is toast. You'll bend your valves, destroy a piston or two and then you'll be looking at a very expensive repair.

So I'd have the whole works done. Tensioners, chains and water pump. Mine will have it done shortly.

Paul

Reply to
Paul M. Cook

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