Hello, recently i got myself a Jaguar V8 VP with 64k miles on the clock. I read online that secondary timing chains can be troublesome on these cars so i decided to check if it has the “upgraded” metal ones. After taking off cam cover i found out that i still have the plastic tensioners but those seem to be in a good shape. No cracks or wear marks, chain is under strong compression. Should i replace these with metal tensioners or leave them as is? Thanks!

 

I'd say replace as they will fail at some point.

I did them on my XJR when I got it, with 79k miles on. They looked fine as yours did, but once removed I spotted some cracks appearing I couldn't see before removal. Using the cabletie method of attaching the chains to the sprockets you don't even need any special tools, making it an easy one to do.

Long term the primary chain tensioners need doing too as they also fail, but seem to take a lot longer to do so. I've got that job planned for the future on mine & will get a bigger supercharger pulley at the same time, because it'll be off anyway so why not?

 

the problem is the slipper snaps off the piston it’s not something you can catch. the body being cracked isn’t a real problem

 

You're already 1/3 of the way there so I'd do them while you've got it open. They WILL eventually go and I don't think the secondary tensioners give much warning...and when they do go and you skip a couple teeth you run a significant risk of valves impacting your pistons.

Primaries and chains, etc ought to be done too, but at least if those let go, you're just stuck with a car that doesn't run, but it won't trash your heads.

 

dooo it

 

I am not sure that failure of primary chain(s) will not cause bent valves. Will the primary chain failure not trash both, the intake and the exhaust valves?

 

I have no direct experience with this, just going off something I've read more than once in this forum and it wasn't contradicted at the time...I probably shouldn't repeat it like I did without knowing 100% though. You may be right and its certainly worth doing the full kit.

 

CHAIN failure yes will cause bent valves all over the place unless you are very lucky. Chain GUIDE failure generally gets noisey long before it will actually cause a problem, which is not necessarily the case on the secondaries.

That said, if its a keeper and you either have the time or the money, then I'd do all the chains/guides/tensioners.

 

Life’s too short, just reinstall the valve covers and drive it til the tensioners break next year.