Until quite recently I have been of the opinion that the there was no problem with my car as it ran as sweet as could be.  However, after an 80 mile round trip to Eurojag in Darlington to collect a tyre valve for my BBS split rim alloys (another story for another day) I have changed my mind.

I asked out of curiosity if they had any AJV8 engines in stock.  Apparently this was a stupid question, met with lots of sucking through teeth and shaking of heads.  “No sorry, there’s a waiting list”.  Followed by – “Why – Do you need one?"  “No just enquiring as I have a Nikasil engine and I’m afraid it may pack in one day.”  In some ways the response was quite encouraging, it’s apparently very rare that they come across Nikasil engine problems these days. – “BUT - we get loads of people coming in with blown engines because of timing chain tensioner failures.”

I had been under the impression that you get a reasonable warning of tensioner failure as apparently the engine can sound a little “rattley” when you first start it up.  Well this is true – sometimes – but not always.  Recently, several people have told me of their experience of sudden catastrophic tensioner failure measured in seconds.  Failure to immediately turn off the engine leads to a very sudden snapping of chains, followed by valves meeting pistons, followed by a very large bill for a replacement engine – If you can get one! - Time for a re-think....decided to follow the advice of so many articles in the Jaguar magazines and get the upper tensioners replaced with the new improved 4.2 Litre version and to get the water pump replaced at the same time.  The old style pumps have plastic impellors which can break down over time and lead to engine overheating.  At around £50 for a new metal blade water pump it makes perfect sense to replace while the work to the tensioners is being carried out.      I 

My car has covered 75,000 miles and I thought it was in perfect health, having led a relatively unstressed life.  WRONG...Look at the two photos.  The plastic body on both tensioners had split and it was obviously only a matter of time before the body would fail.  Possibly in a year – possibly in a week……….There’s just no sure way to tell.

If you have a pre 4.2 litre AJV8 engine XK8, XJ or S Type – my advice is don’t think about it any longer – bite the bullet and get them replaced now before it’s too late.

You have been warned !!

Brian Green