Hello all, I just purchased a 2000 XJ8 (steel liners) with 97,000 miles on the clock. The engine sounds perfect at the moment. With all the talk on tensioners and their failure, how soon should i go about replacing these? My local Jag mechanic said that the problem is blown out of proportion and he rarely sees an issue, but to read the Jag forums, you'd think it was a pandemic. Anyone have a balanced view on this?

 

The best answer to your question is, "before a secondary tensioner breaks".

Failed secondary tensioners is not "pandemic", and it is not a rare occurance. I'd have to point out that some of your sources of information deserve a bit more scrutiny: a 2000 XJ8 engine block does not have steel liners, unless it has been rebuilt. If it was rebuilt after approximately mid 2002, it may have the lastest style aluminum bodied secondary tensioners already installed.

That said, the issue centers around the cost effectiveness of preventive maintenance. There is not any predictability to the present condition of your tensioners if they are original: some last alot longer, some fail much earlier than 97,000 miles.

If you suffer a failure and are fortunate, there might be no added expense. If you are unfortunate, the worst case is that your engine can suffer catastrophic damage.

I work on a fair number of later model Jaguars identical to yours. Sometimes I write the words "never seen that before", and realize they have little meaning: perhaps a dealer tech that works on a given model every day for years is quite accustomed to seeing a fault that is a new one on me. Perhaps, working on predominantly lower mileage cars, they have not seen examples of a failure that is easy for me to point to as a pattern.

There are three destroyed engines in my shop thanks to failed seconday timing chain tensioners. There is a guy on Roadfly XK8 looking for a piston and cylinder head right now...that is the resultant damage from exhaust valve breakage which can occur when the secondary chain is broken by the fragments from its failed tensioner. Does it happen often?
No, and I don't think you can calculate probability. All you can do is spend a little money and not have to worry about it.

 

Is this a new engine with steel liners? Otherwise replace the tensioners. Mine were shot and there was no warning sound.

 

Can you give me more information on the liners? One of the other Jaguar forums and a number of other online sources indicate that the Nikasil liners ended mid-year 2000 and the change can be identified by the last digits on the VIN, if there are 6 numbers at the end it's Nikasil and if there are 5 it's steel. Is that not correct? Pardon the question, I'm new to the Jag world.

On the tensioners, that's all I needed to know, I'm going to tackle that ASAP.

 

Alex, that was the original and widely circulated misinformation.

The engine number is the determining factor, and does not have a direct relationship to the vehicle build date. The closest line that has been drawn in the silicone is engine number 00 08 18 XXXX, and it's stamped on your engine or recorded in the Jaguar database.

 

Gotcha. Thanks. Pity that hasn't been more widely circulated.

 

I struck the 2001 line from my original post, because the wording was likely to inflame needless argument. If you would like to do the same, that would be preferred. I stand on all of my statements of fact regardless.

 

Gotta love the flamers. I'm a mod on V70R.com (I'm mostly a Volvo nut) and you have to keep the fire-extinguisher handy at all times.

 

Try Advance search, my name, tensioners, look back for a while.

 

JTO, you need your own 'sticky' page, with all your best work. You can simply say, 'yup, lots of discussion, see my page for the topic you're inquiring about.'

I realize you regurge alot of info, and I appreciate it when you can't provide a link to your dissertation on the fly.

 

Regurge ;}

 

Hi JagtechOhio,

Maybe you need to put all your best work in Notepad files and when you have to regurge, then do a cut-and-paste from the appropriate file.

By the way, I noticed your garage has four engines on the floor. Are those the dead ones you mentioned earlier?

Mike

 

Those were the replacements then. The core pile is a bit uglier now.

 

A recent Jaguar World article on buying used sedans (saloons) recommended that for those cars with the 4.0 V8 engines replace the cam tensioners and water pump as a preventative measure as the original items contained plastic parts which degraded over time. As JagtechOhio mentioned earlier, failure is not always predictable.

Mike

 

I have ordered the secondary tensioners and gaskets, I opted for the Ford parts since they were cheaper. If all goes as planned I'll crack open the engine and replace these this weekend. If anyone has any last minute suggestions, drop me an email or PM, any help is greatly appreciated.