Just bought a 2011 XJR8.
Just bought a 2011 XJR8.
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Big Rod

Original Poster:

6,261 posts

242 months

Monday 11th June 2012
quotequote all
And I love it but it rattles on idle.

Is this beyond any doubt the top tensioners or is there anything else that makes a rattle like that?

Jaguar steve

9,232 posts

236 months

Monday 11th June 2012
quotequote all
A 2011 XJR8? scratchchin

If it's a X308 (1997-2003) then it may be the secondary tensioners. If failing or failed you will hear a russling/rattling noise similar to a pushbike chain being dragged over the chain guard which'll be worse when cold. You may also have a sharp rattle on start up with the mk 1 tensioner which is actuated by oil pressure. It'll rattle untill there's enough pressure to push the piston out to tension the chain. The mk 2 type fail silent and deadly as there's a spring to push the piston out instead of using oil pressure.

The only advice I can offer without hearing it is to not start the engine again. Instead either get the car trailerd to a competent mechanic, or remove both cam covers yourself and physically check the condition of the tensioners and tightness of the exhaust cam chains. If the tensioner bodies are either red/orange (mk1) or cream/dirty brown (mk2) then they should be changed anyway for the metal bodied mk 3 design available to retro fit from around 2005 onwards

If that's the problem and the chains are slack enough to rattle you're running a serious risk of jumping teeth on the exhaust cam sprocket - one tooth will cause running problems, any more will cause a coming together of valves and pistons.

Check it or wreck it - your call smile



Big Rod

Original Poster:

6,261 posts

242 months

Monday 11th June 2012
quotequote all
Thanks for the reply.

Well spotted, it is 2001 vintage. LOL

Which I guess puts it right on the crossover. I had hoped it was the later incarnation.

Anyway, I took it to a good garage today and they inspected it with a stethoscope, (interesting contraption they've derived from a knock sensor attached to some sort of computer with a set of headphones. I was impressed!), and let me listen. The offside bank is rattling away like a bag of bolts the nearside one isn't as bad but on it's way out. It's booked in on Thursday to have them replaced.

I initially thought it was supercharger bearings but it's as quiet as a mouse.

I'm likely to be a regular vistor here for the foreseeable. thumbup

I'll be looking at having the front suspension looked at before I have the geometry set.

Other than than it's like driving a fast attack aircraft carrier! What a car!!

Edited by Big Rod on Monday 11th June 21:18

Jaguar steve

9,232 posts

236 months

Monday 11th June 2012
quotequote all
The revised AJ27 V8 engine did away with Nicasil lined bores and had a more robust waterpump and throttlebody. It also has the 2nd gen tensioners, but these are considered fragile too - and don't ususlly give the warning rattle the earlier one made when failing. Apart from these issues and the need for a gearbox oil change the X308 is a fantastic car, and a real bargin.

Enjoy. thumbup

Big Rod

Original Poster:

6,261 posts

242 months

Monday 11th June 2012
quotequote all
Jaguar steve said:
The revised AJ27 V8 engine did away with Nicasil lined bores and had a more robust waterpump and throttlebody. It also has the 2nd gen tensioners, but these are considered fragile too - and don't ususlly give the warning rattle the earlier one made when failing. Apart from these issues and the need for a gearbox oil change the X308 is a fantastic car, and a real bargin.
Yeah, once the immediate worries are addressed I'll draw up a list and treat it to a massive service to accomodate gearbox oil changes and whatnot. It really is too good a car to 'let go'.

Jaguar steve said:
Enjoy. thumbup
Already am Steve, I adore it!! I don't remember having a car that I just want to get in and drive so much just for the pure hell of it. It's quite frustrating looking at it in my driveway knowing that I really shouldn't start it up!!

Ecurie Ecosse

4,812 posts

244 months

Tuesday 12th June 2012
quotequote all
When you are getting the tensioners done you should get the lower supercharger pulley upgraded - for even more zest smile

Big Rod

Original Poster:

6,261 posts

242 months

Tuesday 12th June 2012
quotequote all
Ecurie Ecosse said:
When you are getting the tensioners done you should get the lower supercharger pulley upgraded - for even more zest smile
Already been done apparently.