Goodmorning,
i'm Andrea and i write from north of Italy.
I have just bought a xj6 3.2 x300 with 148.000 km, year 1996.
I heard a strange noise while i run (expecially during accelartion from 1800 to 2200 rpm)
i changed the upper tensioner and the oil (castrol 10w60) last week, but that noise remains the same. it sounds like a little rattle.
i'm so worried ...
How do I know it’s the chain or something else ? ( please excuse my bad english)
Can i attached a recording (movie or sound recording) ?

Can I try to make a movie?

 

Welcome to the Forums.

I have attached my PDF I wrote a god many years ago regarding my findings with this.

My 3.2 was worse than the 4.0R.

That oil sounds a tad too thick for my liking, I ran 15W40, or 10W40, whichever was on special at the time of need. That could be a contributor.

 

the resonance at 1500-2000 RPM is dangerous? it is only annoying or i might brake something?
thanks for your helps

 

Things rattling as that one does, are scary. Excess wear on damper guides etc will be more significant,

I have nevr heard of a chain snapping, and in reality a SMALL slap/rattle is SMALL excess clearances, not huge gaps.

Still not pleasant to hear, and I had mine apart a few times before I solved it, I simply could not tolerate that noise, no matter the brand of car.

 

many thanks for the help and advices.
today I noticed that the noise shows up around 2000/2200 rpm , when the engine is under load.
could be an heat shield under the car or in another area?

 

It may indeed be something else, as that rev range seems a little high for the classic timing chain rattle. Also, you haven’t mentioned the other standard symptom , a rattle on cold startup, so maybe you are not afflicted with this common problem.
However, if you do have it, the good news is that nothing bad seems to happen, even on engines with much higher mileages than yours. An annoying problem nevertheless and there are several threads cataloguing different approaches to fixing it, mostly unsuccessful!

 

goodmorning,

thanks for your answer.
I've never heard rattle/noise at cold start.
Before changing the oil (from 5w40 to 10w60) and the upper chain tensioner , I heard short rattle at warm start, but now is gone.

 

Cold start rattle is the 1st sign of upper chain tensioner issues.

The 1500ish rattle is varied, and can be the lower chain tensioner simply getting tired. Similar item, but NOT pressure fed. It relies on run down oil, into the "cast funnel", and then the "whipping" of the chain on the guide to "pump up" pressure. Very simple thing, but fiddly to understand, it took me a while to grasp is.

That heavy oil still worries me, BUT, ots your car and market. As said, both mine ran 10/40 or 15/40 all tear round.

 

castrol oil selector (for italy market) recommends 5w40 or 10w60
I tried 5w40 but i heard the chain rattle at warm start (even with the new upper tensioner)
I changed with the expensive 10w60 and the short rattle at warm start is gone.
Remains the annoying noise when accelerating (2000/2200 rpm) while running.
I tried to reproduce the noise in neutral ,but nothing. I heard it only when i'm running. Could this be a clue?
could be the automatic trans? the exaust manifold or other parts could cause such noise?

 

lower chain tensioner

just live with it. they never jump

 

thanks

 

thanks,
i think you are right.
yesterday i checked carefully and i heard the noise in the area where the lower tensioner is housed
sometimes the noise is minimal,sometimes a little more,sometimes disappears.
I trust in your experience
if it’s just annoying, I will learn to live with this.
this is my first Jaguar and i love it. Wonderful car !
I’m trying to give this car the best care

 

good evening,

i tried to record with my smartphone the sound of the engine on the run.
i put the phone in to the engine bay near the front of engine.
you can heard the noise during acceleration
is it the lower tensioner as we said?
And I'll just pretend like I didn't hear him and keep right on going ?
what's your opinion?
thanks

 

I had both the cold start rattle and the 1200-1600ish rattle so embarked on a timing cover off, full replacement of chains tensioners and guides. Not an especially easy or fun job, but cured the 1200-1600 rattle, but not the occasional cold start rattle.
The various threads seem to have arrived at the conclusion that the cold start rattle is due to oil pressure escaping from the upper tensioner, despite a ball valve intended to stop it from doing so, and I am inclined to agree with that diagnosis as the only people I have heard say that they have cured it are using much thicker oil, which in my mind runs grave risks elsewhere in the lubrication spectrum.
As has been said already, there do not seem to have been any reports of chains breaking or timing jumping, so doesn’t seem like a real world worry. Perhaps when your engine gets to 500000miles or the noise starts to drown out the radio it might be worth reconsidering!

 

Chain noise update:

I finally founded a mechanic who knows jaguars.
He also agrees that it's the lower chain tensioner.
According to him the noise is minimal and is present only in that range of RPM .(1900/2200)
He says that for now it is not necessary to do anything.

Do you agree? (is just annoying and there is no danger?)
​​​​​​​We could do something to reduce the noise ? (type of oil / additives / or others....)

thanks in advance,

 

Ref that timing chain rattle at startup there was a Jaguar service bulletin (SB)about his problem.
From memory it was a change to the hydraulic timing change tensioner which kept oil pressure in the tensioner rather than allowing it to bleed off
Someone more skilful on computers than myself might be able to unearth that SB