Chain Tensioners After the seminar.

[bobwnm]

Having been worried about the chain tensioners and intending to do the job this winter I picked up from David Marks on saturday that the change over period for the new tensioners could have been early 2002.

As my 2002 convertible was registered in March 2002 and was probably built in '01, I took David Marks advice and decided to investigate before purchasing any parts! On taking off the cam covers I was delighted to find the latest alloy tensioners and the unmistakeable primary chains as described at the seminar!
For anyone else with a similar aged car mine is :-

VIN. SAJAC42M12NA26927
Engine No. NB0110260824

It certainly gives peace of mind, even tho' the car has only done 39000 it was always in my mind!
There is no record of this work been done in the service records and the one previous owner has no knowledge of it, so it looks like it was a factory fit.
The seminar has paid for itself allready!

Bob

[mike020150]

Hi Bob, That's really valuable information. As I mentioned at the seminar, Jaguar lists a VIN number change point (the start of the 2002 model year) but engines were not necessarily fitted to cars in the order in which they were built making it difficult to be sure precisely which 4.0 litre engines have the metal bodied tensioners. The 2002 MY cars will have been built starting after the factory summer break. Your engine number information tells us that your engine was built on 26th Oct 2001 and will act as a useful pointer for others with cars built for the 2002 MY. Mike.

[D_Doran]

I hope you are correct about the changeover date. Is there any likelihood that a previous owner changed the chains and tensioners?

If not, I may have a big smile on my face...

Engine Number NB0112141655 (It was it's birthday yesterday and I didn't know!)

Damian

[bobwnm]

Hi Damian,
The previous owner of my car told me only one brake pipe had been replaced under warranty and that no other work had been done other than servicing , tyres and brake pads. The (skimpy) service records back this up.
When I took the cam covers off I got the distinct impression that no one had delved farther into its innards than to the plugs! On top of that the engine has the morse bottom chains and I am not sure that they come with the replacement 'kit', looking at the parts in photographs they look like conventional chains, the same as the top chains, but I could be wrong on this! no doubt someone will verify it or not!
Why not take the cam cover off for a look, the offside is the easiest you could have it all done in about an hour if you have the tools!
good luck,
Bob

[D_Doran]

I wouldn't even consider trying it!!!!! I'd end up with extra bits left over!

Next service, I'll ask them to take a peek.

[mike020150]

Since the earlier correspondence, there has been a suggestion that engines built subsequent to 12th August 2001 may have the metal tensioners. Please note that this information has not been confirmed positively so if anyone has examined their 4.0 litre engine's tensioners on an engine numbered after 0108130000 (ie manufactured from zero hours 13th August 2001 onwards) and can confirm the presence of metal tensioners, it would be very helpful. Mike.

[xk82002jaguar]

To let you all know my experience. My car was first registered 17/05/02, my VIN SAJAC41M32NA29006 and Engine number NB0202131435. After seeing the possibility of my tensioners being the 4.2 type, I became curious as to what mine were. So I asked my trusty? independent to have a look during its service at the beginning of March.
My car has 50K on the clock. My independent said they were not the new 4.2type and recomended I change them whilst it was in bits. I assumed that just looking was going to cost me a few bob, so changing them was a good idea, then I could forget them. I asked my independant to keep one of the old tensioners so I could determine what type it was. The tensioner they gave me was the first generation, which I was surprised to see. Albeit in very good condition. Can anyone confirm it is possible to find a Feb02 engine with 1st generation tensioners.
Thanks

[daveji]

Hello all
I hope you do not mind a contribution from an interloper from the X308 forum but regarding when the latest type of aluminium bodied tensioner I quote from Nigel Thorley's book "You and your XK8" page 110.

"Tensioners have been upgraded over the years,the latest type,introduced in February 2005,being an aluminium bodied version of the secondary (upper) tensioner."

This means ALL 4.0 litre XK8's and some 4.2s started life with plastic bodied upper tensioners,as well as ALL V8 XJ (X308) Saloons.

Makes you think doesn't it?

[Bob5043]

Hello all
I hope you do not mind a contribution from an interloper from the X308 forum but regarding when the latest type of aluminium bodied tensioner I quote from Nigel Thorley's book "You and your XK8" page 110.

"Tensioners have been upgraded over the years,the latest type,introduced in February 2005,being an aluminium bodied version of the secondary (upper) tensioner."

This means ALL 4.0 litre XK8's and some 4.2s started life with plastic bodied upper tensioners,as well as ALL V8 XJ (X308) Saloons.

Makes you think doesn't it?

Hi All

We just spent yesterday replacing most of the suspects on the engine of my Feb 98 XK8. I bought the car about 18 months ago at 53 k miles and have been intending to get round to this job for some time, as the car is approaching 58k now, but to be fair has never shown any sign of chain rattle. Following the seminar I collected all the necessary bits together mainly from either Anthony at Berkshire Jags or from Stuart at Colliers parts in Tamworth. Both were extremely helpful and informative. We replaced all the chains and tensioners, and found that both fixed primary guides were breaking up, the B bank quite badly,with a very slight bend in the middle. the primary tensioners were still intact, although one appeared a little weak, but the secondaries were both flawed identically with cracks about 3mm long starting in them. The actual slippers at the end were still intact and not showing particularly heavy wear and tension seemed adequate. Anyway it now has a full set of the latest metal tensioners. We also changed the thermostat tower and stat, the two heater hoses in the Vee, the water pump,and obviously renewed all the seals in the cam covers and the timing chain cover, as well as doing all the service items such as plugs, oil filter, oil change and coolant change.
One small item noted was that whilst we changed the crankshaft seal in the front cover we also changed the little O ring in the crank damper which had gone pretty hard. I am not sure if the water pump was the original, as it had a joint rather than O ring seals but although apparently intact, there was just a faint sign that one of the blades was starting to fracture. I suppose you have to accept that some of the plastic and rubber is probably getting harder as a function of age as well as use as these cars get older, but having inspected all of the bits that we took off, they hadn't reached a critical condition, but it was time that they were done.

Most of the job was done for me by a great local ( Birmingham) independant called Chris Morris who has just started up on his own after twenty years working for local main agents. He very obviously knows his stuff on XK's and indeed all the other Jags and has obviously done boat loads of warranty work on this sort of thing over the years. He has all the kit for doing diagnostics on electrics as well and is mobile. I picked up loads of info working with him for the day and he has some interesting takes on all the usual problems, having been involved in fixing them all for the last twelve years or so. The whole job took about seven hours, including tea breaks, with me cleaning up all the bits, changing seals and things, getting in the way and asking questions, and the charge was extremely reasonable. His number is 07833 290065 and I can thoroughly recommend him.

Bob

[mike020150]

The Jaguar information about change points for the timing chain tensioners is not entirely clear and unambiguous. The quote from Nigel's book refers to the point (2005) when Jaguar released the alloy tensioners as listed spare parts available over the counter from dealers. It appears that the engine line had been fitting the alloy bodied units somewhat earlier, possibly since the start of the 2002 model year (VIN A24195). Talking to Jaguar specialists none, so far, has found the earlier tensioners in any 4.2 litre engines and consistent with Jaguar information, several 2002 MY 4.0 litre engines have been observed with the later tensioners. Mike.