Hi guys,
today had a very bad day. A month ago started hearing rattling noises after cold start, later on after warm start as well.
Everything pointed to the failing upper chain tensioner, so ordered from britishparts.co.uk and changed it.

I did everything by book - removed the cover, the camshaft sensor. Pushed against the blade to prevent the piston from falling in to the engine.

Took the new one, inserted and bolted in.

Took the relay out started the starer to pop up the piston.
At the beginning i thought that the piston didn't pop up because when i stopped to turn the starter rattling noise was still there.

After couple attempts is started the motor, no noise, seems to be working everything, but after some time, started one more time and bingo the same rattling noise as it was before.

After couple miles driving on hot when started the noise is not so intesnive, but still is. When left to cold situation is worse.

After that i changed the engine oil.

Could i mess something with the installation?

 

I have had this problem before too. I bought a new tensioner and re-used the old housing. (old housing is much easier to install and engange the tensioner) After starting, rattling was still there. Did a fresh oil job and no more rattling.

Sometimes i still hear it when starting the engine but I believe its the starting motor engaging and it hangs a bit then.

There are alot of posts about this problem, some say its the rails, some say its the starter, some say its the tensioner.

What oil do you use?

 

All day today i was driving all around, trying many car starts on cold, on hot etc.
And you know I might have discovered that not the tensioner is the problem.

When i did the oil change ( i used ELF synthetic 5w30) i noticed that tha rattling sound kind a disappeared, but the dzhirgling sound is on board. Very similar to as if the starter is hang on . Those noises where very mixed up and it was hard to determine which is what.

So i did very short turn on key, to not to start the engine, and after the short engine turn the engine stops turning and that dzhirgling sound is present for second or two.

So my conclusion is that if its the tensioner it shouldn't rattle when the engine isn't turning.

When it rattles after engaging the starter maybe its the problem in starter itself.

If its the starter where is key point of repairing it? Anyone maybe had this problem before?

 

same thing for my xjr6, replacecd tensioner snd noise was gone for 4000 km and came back. Did some research it seems like the older xj had similar tensioner design but they do not rattle, now the only difference is they used thicker engine oil so the tensioner did not loose pressure overnight. so i switched to 20w50 oil and no more rattle from that point on

 

Well I dont know about the thicker oil, because when the engine is hot I guess the oil thickness is very thin anyway. And the tensioner looses its pressurised oil when its hot.
Anyway now I used 5w30 wich is thin, before used 10w40.

Now after changing the tensioner I have the rattling of chain only in the morning, on cold start, not after every hot start. The rattling on hot start it appeared to be the failing starter.

I guess I will try to dismantle the new tensioner and put a 3 mm spacer on the spring. Some say it helps because it gives more tension to the spring.

 

Ummm It did the trick for me, certainly the oil is way thicker when hot, since it is 20w50 , even when cold it id 20. give it a shot, you will be surprise. Downside of this is prob your gas mileage, i notice it has gotten worst since i switched.

 

But one thing i don't understand, what causes the completely new tesioner to fail? It is brand new and rattles like hell.

Also about the 20w50 oil, according to specs is says its working ambient temperatures are from 0 degrees C to 140 degrees celsius. In winter we have here temperatures reaching -25 Celsius. How this oil is going perform under such temperatures. The starter will not be able to even turn the engine? What temperatures do you have in your area?

 

Long time Jaguar mechanics have been recommending 20w50 to address this issue, in combination with stressing to use the Jaguar OEM oil filter.

If you can verify that your filter has the exact same anti-drainback specs, it should be fine, but the mechanics have warned me that many aftermarket filters do not perform equivalently as OEM and this causes some cases of startup chain rattle.

Once I changed back to using the OEM filter, my rattling stopped.

I ran 20w50 with the OEM filter for a couple years as well with no rattle, but recently tried Mobil1 European 0w40 during the winter and the rattling still remained mostly gone, although I detected a tiny faint rattle every so often on startup. So I think most of the solution was in the filter.

So you might try an OEM filter if you haven't already.

.

 

At first I used some oil additives what supposed to thicken the oil. Since i had 5w30 it helped at some point. Light rattle was heard sometimes all the time.

Now i changed to full synthetic 10W60 and OEM filter, and it solved my rattling problem.

So thicker oil and OEM filter with back valve is a must have in this car.

 

al_roethlisberger ,

Thanks for the tip on the 20w50 with OEM filter usage for this series of engine . The previous owner hadn't changed the oil along with spark plugs for quite a long while and took me 8 days of penetrating oil and heat application just to get the drain plug off . The resulting drained oil was unbelievably ridiculously dirty so I kept a souvenir baby jar of a sample . Just shake my head . Currently just running the cheapest oil and filter on the store shelf just to flush and clean with Rislone , the bad oil out

 

Well i have to say, the joy was way to early. Today on one of car startups I heard a tiny rattle.
So thicker oil 10w60 and oem filter not quite solved rattling issue.
But feels like rattling got more less often.
Although engine got very smooth with this oil, even startup takes less starter turning.

On rattling issue have one more idea to take tensioner out and put some spacer to the spring seat, adding this way more power to the spring.