chain tensioners
 

my car is a xkr approx april 2002..vin sajac41n42pa29240..anyone got any info about the tentioners..are they the metal type?
I have lots of service history but none about tentioner upgrades..any help would be good..

Tensioners
 

Reportedly, in a number of threads regarding tensioners, metal tensioners were placed in engines mid August '01. Your vehicle VIN number and engine serial number are two different numbers. Your dealer should be able to cross reference the two numbers to give you an engine build date.

2003 XKR 4.2 3rd Generation Timing Chain Tensioners
 

Hey Dennis;

I just went through this over the week end in great depth.

See this thread:

https://www.jaguarforums.com/forum/x...-advice-62417/

I understand your concern as I got a bit nutted up by misleading info on the net.....but the short answer, thanks to the Jaguar Guru's on this site, is yes Aug. 2001 is when they went to the final design for the tensioners and they are made out of metal and have a new chain design as well.

That is the big advantage of the 4.2 engine plus they stopped using the Nikasil cylinder liners in 2000. Another 20 HP with better MPG figures is not bad either.

Unless yours is making a noise on start up then don't worry.

The following is in regard to plastic tensioners but if you have a noise as described be sure to park it right away.

When a plastic tensioner shatters or wears to the point the cam chain becomes loose, a rattling around can be heard in the cam area at the front of the engine. Usually this happens on start-up, when the engine is cold.
(Note that a rattling sound does not necessarily mean broken tensioners. There can be other causes that are not as drastic but nevertheless indicate trouble.)
On some occasions there is no rattling sound to serve as a warning. As the tensioners wear, the cam chains can become loose and eventually jump one or two teeth on the cam sprockets – usually on a cold start. If the chain jumps one tooth, rough running will be experienced. If it jumps more than one tooth, the valves on one block will contact the pistons, resulting in engine failure.
http://www.jagservice.net/images/warning.gif If upon start-up you notice a rattling sound from your 1997-2000 Jaguar V8 engine, or unusually rough running, turn off the engine immediately and DO NOT restart it. Have the car towed to a Jaguar specialist service facility for inspection.
Jaguar V8 Secondary Tensioners - Preventive Replacement


Please note that I called the shop cited in the website above and confirmed that they need to update their website to reflect that the plastic tensioners were changed to metal from Aug. 2001 on.

Good driving and remember as my Daddy always said "be smooth and fly low".

jamjax

My understanding is that it was engines built after August 13th 2001 that were fitted with updated tensioners.
This does not mean that a car built after that date could not have an engine built earlier.

Engines used on the assembly line are made before the car is made!!!!!!!!!!!!!!!!!!!!!!!!!!!

You need to read the ENGINE ASSEMBLY DATE.

There are early MY cars out there that have had a replacement engine in WARRANTY that have the newest components if they were repaired with a later engine.

VIN is NOT a reliable way to determine engine configuration.

I have a 1999 engine in my shop that I had steel liners installed!!!
It has an engine number that will designate it as an early engine WITHOUT STEEL LINERS.

The world is full of discrepancies.
Most of my customers have had the tensioners replaced.

Pull the '#/*@^&!$ cam covers and LOOK' is the only way to be SURE.

bob gauff

Both sides. One member had new on one side, old on the other.

the problem is that i would like to have the tentioners to hand when taking covers off so that i could do the the job..thats why i would like to confirm one way or the other first..it seems crazy that one side old one side new..but believable..jag dealer not helpfull

If you pop the cam covers off and find plastic tensioners, you should be able to get new parts pretty quickly. I ordered the Ford equivalent tensioners online, and had them in just a couple of days. If you can't wait, call a few Jag dealer or Ford parts departments first, confirm that they have the parts in stock, and then pop the covers off. You might want to consider replacing the cam cover gaskets while the covers are off, along with the spark plug seals.

That member with two different tensioners in place was me, by the way...both sides sporting new metal tensioners now, though.

thanks for your reply..the main problem is that this is my only car in daily use..my wife has a car but she works as well so its a case of doing the job there and then..the poss of any one local having the parts in stock is very slim..british parts is best..next day delivery..may have to bite the bullet and get parts anyway

Why not get the tensioners from a Ford dealer and make sure they will take them back if you dont use them.

what a bunch..just been onto Fox jaguar cheltenham who have done a lot of service on this car..they say car will have old tentioners.. metal tentioner only fitted to 4.2 2003 cars but the can fix it for £1200 I then phone Guy salmon northhampton who were original supplier of the car and they say definatly got latest tentioners..stratstone solihull say yes got latest tentioners ..Taunton jaguar who have olso serviced the car say will phone me back but i wont hold my breath..think its time to get the spanners out

its a good idea but the only people that will do that is british parts but they charge 25% restocking fee plus post and packing and they only give a few days to return items..

Most of the time you see that an engine is placed in a car within 2 months of when it was been build, as your car is build in April 2002 (so about 8 months from the first 4.0 engines build with the new morse chain & metal tensioners) chances are very very slim you have the "old" style tensioners.

It is also well documented in the Jaguars electronic parts system when this change took place, so these non-believers can check that system.

One side if you see the new silent chain.

Dr, he'd have to know what the old chain looks like. (although, there are photos around) Dennis, if you don't mind bending over your wing (fender) and futzing around with some difficult to reach but not frozen tight nuts, taking off the covers is easy and you can put them back on while waiting for parts if needed. In the meantime, you get better acquainted with your car.:icon_drink:

yes..im going to do this but im getting gaskets first just in case

Does anyone have information on a definite cutoff date for the last of the Plastic Tensioners installed in XKR's?

I am hoping my 2003 July Registration is beyond the questionable period of engine production up to Aug. 2001.

It doesn't seem credible that they would have built two years of engines in advance when they were implementing just in time production standards.

Pity the Factory won't enlighten us on this expensive design defect when so many manufacturers have 100,000 mile warranties.

jamjax

A registration date is by no means a build date of your car (usages differs per country) and the build date of your car is always later than the build date of your engine.

If you want to know, check your engine serial number (this is the build date of your engine), and if it is after the 13th of August you are fine.

my engine number is pb0202012324 can you confirm any info from this
thanks

Chain Tensioners in the 4.0 AJ26S-AJ27S engine versus the 4.2 AJ34S
 

OK has anyone seen any evidence of plastic timing chain tensioners in XKR 4.2 AJ34S engines?

The 4.2 was by definition a new engine with the improved tensioners and chains.

Has anyone seen the 6 speed ZF transmission mated to an engine with plastic timing chain tensioners?

Here is a very useful link for the breakdown of all the engines, specs, and guides:

http://www.super7thheaven.co.uk/Jaguar-AJ-V8

For the record my VIN is SAJAC42R643A37223 which actually puts it into the 2004 MY specs by about by about 500 cars.

Also I have come across late production 2002 XKR's with the 4.2 engine in them.

I would love to get my engine number but am out of the country until next month.

And again it is a pity that the factory won't clarify this and it requires an engine number decoder to know what bits are in your engine.

jamjax