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Timing chain tensioners

Posted: Wed Jan 11, 2012 4:17 pm
by djws61
As a precaution I’ve just had my 98 XK8 with 83k on the clock checked to see if the tensioners have been updated and they haven’t, this was done by my local garage who have looked after my cars for years, the secondary (upper) timing chain tensioners, chains look in good condition and the car has been running great with no noies, knocking etc, lm going to have these upgraded to the new metal tensioners as a safe-guard. I have spoken to my local Jag dealership for a second option and they have advised me (at huge cost) to have the secondary (upper) timing chain tensioners, lower tensioners and chain guides replaced! Does anybody think this is necessary or can someone advise who is or has been in the same situation?
Thanks

Re: Timing chain tensioners

Posted: Wed Jan 11, 2012 7:53 pm
by Nik
It's a good idea to do the lot , I'd personally change the chains also at that mileage , then you should have complete piece of mind , don't forget to have the water pump and thermostat changed for the later versions unless already done ,

Hope this helps ,

Nik

Re: Timing chain tensioners

Posted: Thu Jan 12, 2012 12:33 pm
by mike020150
Replacing all the tensioners, guides and chains is the best (and most expensive) option for any car intended for long term retention. The lower tensioners do not suffer as badly as the upper versions or fail as catastrophically but the lower guides do crack with age/mileage and none is less than 10 years of age. It would be really annoying to tackle the upper tensioners only to find later that the primary chain items also require replacing and that much of the initial work has to be repeated. The decision to change the upper tensioners or the full set of components is a question of how much peace of mind is required. Mike.

Re: Timing chain tensioners

Posted: Tue Mar 06, 2012 3:18 pm
by WULLIE4567
Hi
Yep I would do the lot much safer, as Mike & Nik say. I done my own & hired the tooling from the club a few years ago, if you intend to keep her it's worth it. Many swear by just doing the top chains Mmmm, ok, but then they have to join the top chains with a link (same as a bicycle) :? have a wee look at my albums in the photo gallery.

cheers
Wullie. 8)

Re: Timing chain tensioners

Posted: Tue Mar 06, 2012 6:16 pm
by J44EAG
Here is a plastic backed primary chain guide taken from a V8 that had covered 162,000 miles. Note wear on the guide and the crack in the centre. As I understand it, even with cracks evident, these primary guides can soldier on for a considerable mileage without a high risk of failure.
Cracked V8 primary chain guide 162k miles.jpg
Cracked V8 primary chain guide 162k miles.jpg (53.77KiB)Viewed 4042 times
Here is a set of replacement guide blades made from aluminium developed by Neville Anderson to overcome the cracking issues shown in the image above. Note the extreme left hand blade in the image has a machined rebate approximately half way up the blade. Neville found that many of the V8 engines he dismantled had a problem with the primary tensioner sticking inside the body and not ever able to even reach the first notch on the ratchet. To overcome that, Neville rebated the blade to allow the tensioner inners to expand more easily and exert pressure on the blade from the moment of installation. The original plastic tensioner was also changed for one made from aluminium.
Neville Andersoni.jpg
Neville Andersoni.jpg (92.25KiB)Viewed 4042 times
I seem to recall that the original primary guides were on back order with Jaguar some time back. I wonder if that is still the case. Can anyone confirm one way or the other?

Mike K

Re: Timing chain tensioners

Posted: Sun Oct 13, 2013 3:43 pm
by jeff1954
Hi All
I'm thinking about buying a 2005 XK8, Will all the problems with timing chains ect have been ironed out at factory level or would they still need upgrading.

Jeff

Re: Timing chain tensioners

Posted: Sun Oct 13, 2013 4:27 pm
by robv12
4.2 engines are bullet proof, so no worries here