If im hearing a rattle from my timing chain I only need to get the revised tensioner correct? Or do I need to get a new chain as well?

 

Secondary timing tensioner only, unless the sound doesn't go away.

 

As said, the revised top unit as the "first" step.

Mine required major surgery and clearly showed the results of real lousy oil change mentality. All chains, dampers, tentioner units, now quiet as it should be.

My Jaguar parts supplier is seeing an increase in demand for these top tensioner units of late, so they are still giving issues and wearing out prematurely.

 

What sort of mileage do these parts normally last till

Please dont say 107k

 

Thats a bit like "how long is a piece of string".

Mine was noticed at 143000kms, and it took some time to convince myself that these newer engines (long time with V12's and XK 6 cyl) needed major surgery at such minimal kms.

The top tensioner made a difference YES, but my 480k kms XK 4.2 is WAAAAAAY quieter in many, many ways.

Push came to shove and the timing cover came off, and the MESS in there was beyond belief. Most of the rubberised contact "stuff" was worn to the metal.

Very sad oil change periods and possibly lousy cheapo oil used, although the service documents did not show this in any way.

ALL blades, dampers, chains (oil pump inc) were changed. New lower tensioner piston assembly fitted, reassembled, sweet as.

I firmly believe that engine care by the previous owner/s (most of us are not the first owners of these cars) is the key here. As well as the place they had it serviced, and the quality of the oil that was used. Remember, very few service places are as enthusiastic as we are.

 

From what I have read 100K plus, but I have noise at 53K. The upper is an easy fix.

 

Drew,

Replace the top unit, it is easy as you say, and fixes 98% of the engines.

Sometimes too low kms/miles is worse than high kms/miles, too much cold running, oil never really gets HOT enough, long enough, to boil away all the contaminants that attack engine internals.

We look at 15k kms per year to be average down here, so mine at 166k kms in 15 years is on the low side, so maybe that contributed to the accelerated wear, dunno.

 

We tried the updated tensioner and it didn't help. I ended up going back to the manual version she did quieted down a bit until my mechanic tried to seal the tensioner with out the gasket. He said he kind of preloaded it a 1/2 turn before completely seating. But, without the gasket she had an oil leak after about 4 hrs of driving and the noise has returned. The weird part is I only hear it when she is been driven for 20 plus minutes. I think all pull the vavle cover off this spring and check out the chain guides. I don't want to replace primary!!

 

That top unit is a tad tricky to "fire off" with the camcover ON, but very do-able. The first time you start the engine with the new tensioner you will have an "unholy rattle" that will scare the hell out you. This is the unit "firing off", but its not done yet. That is only the initial firing, now you need to rev it to complete the task. Do this by simply revving it, or go for a drive. I do the latter. Unless this unit fires completely the engine will rattle again when started.

I have had mine out toooooo many times and firing it is scary, you never get used to it, BUT, unless it is fired fully the rattle will remain.

With the camcover off, simple use a long screwdriver and lever against the blade to fire off the spring, then work it a few times, just to be sure.

 

I heard a rattle and my oil pressure dropped to near zero (bounced back up but I freaked out) so I had my 97 XJR (70k miles) taken in to my local Jag place. I've had the car for a couple of years and 10k without a problem.

Was hoping it was only the upper tensioner but they said that was only loose and they believe the sound was coming from the lower tensioner.

It's sounding like a very expensive job - any idea what I'm in for if the lower one does need replaced?

 

Not too sure where you are, but here goes.

The R is not one I am familiar with, so maybe there is more stuff to remove to access the timing cover.

The lower piston assembly is not a known issue, and will have wear marks on it. The more common is the broken damper blades down there.

I did the 3.2 (NO s/charger) in about 6 hours, and bear in mind, it was the FIRST AJ16 I have dismantled, so time is always longer on the first. IF, and that is a BIG if, the dealer still has mechanics employed that know these engines, it should be able to be done in about 4 hours, plus parts.

Oil pressure dropping, then rebounding, sounds more like the oil pump chain is having issues. This is a single row small chain, and mine was sad when I went in there, and the wedge shaped damper was mal-adjusted, so the chain had the ability to "slap" around more than it should.

 

Thanks Grant, I'll give them a call in the morning and mention what you said. This is a Jaguar-only shop and the people working there are very knowledgeable.

Is the oil pump chain as involved to change?

 

Oil pump chain, HAHAHAHA, %^$#ard of a task. The front section of the sump is in the way, and if you got FAT fingers, good luck.

I fiddled with that for a while, as the FEAR of dropping it into the sump and beyond is REAL. I eventually tied some piano wire to it, and proceeded to remove the old one, and then "fed" the new one in. The wedge damper was "like new", as in NO marks at all, so I reckon it was like that forever. In hind sight I should have just re-adjusted that wedge and forgot about it, as the slop in the new chain was damn near the same as the old chain.

Oil viscosity is paramount in these engines, and I run Synthetic 10W/40 in it all year round, and at 210000kms is silent, as I said before.

SIDE NOTE:
We have issues with a lot of engines at work with chain drive oil pumps, where heavy spec oil has been used, and chain wear is high. Looking at what is asked for, and what has been used, the most common is 20W/50 used when 10W/40 is specified. I know it sounds petty, but thats how we engine guys have deducted it. Then pops up Synthetic vesus Mineral, and the subsequent build up Mineral does create, which is obviously directly related to "drag".

 

It appears it was only the upper tensioner that needed replaced. They replaced that to see if the rattle went away and it did.

Disaster averted (I hope).

 

Your shout, I'll have a triple JD on the rocks.

Good news.

NOW good oil, regular changes, and come back in 10 years time and do it again.