Hi Guys

I'm new here but not so new to Jags!
I recently got a Daimler X308 1998 with the early type VVT, i have it stripped down and want to know what i should be looking for regarding the VVT noise?

It's only done 52k miles and needed a good service which i have now completed with a engine flush, the noise is still there and being a techy myself I am 100% sure it is the VVT, i just have no idea what i need to do to fix this!

Is it just a new seal someplace or something more serious? Any help very much appriciated.

Kind regards

David

 

Start here....http://www.jagrepair.com/S-TypeTSB.htm....and read this for some guidance on where to look ....https://www.jaguarforums.com/forum/x...on-s-c-158869/

 

This doesn't explain much regarding the noise I was experiencing.
This is the noise and the guy in the video diagnoses the problem! What he doesn't say is how to fix the issue.

Really need help with this as i don't want to put the car back together to find its exactly the same

 

I have replaced the tensioners but have left it apart until I

know what is required with the VVT.

 

VVT wear is usually identified by using a higher weight oil or an additive such as RESTORE that clears the issue. I cannot remember a 'real' VVT wear failure.

Both of the pictures you post have the plastic tensioner in place for the primary chains so I don't know exactly where you are. In addition, the primary slipper is cracked so you are not anywhere close to discussing the VVT.

 

test point, weren't those early tensioners hydraulic or are they all spring loaded? Mine were spring and cracked, but then again mines a 2000.

Hey DD, how tight are those chains? Any slack and I would replace them as well as the obvious tensioners. Definitely need new guides there DD, like test point says, they are cracked. I'd replace the whole setup....one and done.

 

I would agree about replacing the guides. I just got my 98' XJR back together. If you plan on keeping the car and it's in good shape, I'd replace all the chains as well with the guides. The most tricky part is oil pressure priming the primary chain tensioners with the front cover off so that it takes all the slack out of the chains before putting the timing cover back on. I held medium tension force on the undersides of the tensioning chain rails with 2 large pry bars while my wife cranked the engine over until oil shot out of the primary tensioners and held force against the underside of the chain rails. It's either that or I put it all back together and crank it for like a minute just to be sure the tensioners are primed.

I would start my own post but, while we're on the subject of the AJ26 timing for your car.... I have often wondered if the primary plastic chain tensioners could be upgraded to metal primary chain tensioners?? The AJ26 plastic primary tensioners have a hole that shoots out oil to lube the chain. The AJ27 upgraded metal tensioners do not have that ability. I know the AJ27 oil pump has 2 little spigots to lube the primary chains whereas the AJ26 does not. So, my question is, if I hypothetically replaced my AJ26 plastic primary timing chain tensioners to the upgraded metal primary chain tensioners, would I be looking at a significantly reduced lifespan of my primary chains and guides? Or would there be enough oil draining from the camshafts to feed the chains??

 

I took the pictures pre replacement of chains and tensioners.
There have all been upgraded now.

I was just reluctant to put it all back together before finding the 'vault' with the VVT units.

I carried out the test as shown in the video with exactly the same results.
I have also stripped off the sump and pick up tube to make sure everything is clear which it is. This engine is actually super clean inside as it has only covered 51995 miles with full history.

Someone told me to try replacing the red seals on the VVT but these actually look to be ok and strangely i am not sure if they are actually standard rubber seals, they seem to be made from some kind of composite rubber.

Thanks for the advise so far guys!
Kind regards

David

 

 

The old tensioners were hydraulic only...... no spring! Maybe this was what was causing the noise however mine were not cracked.
Doe's the VVT work off the same pressure route as the tensioners? So if the tensioners were taking up all the pressure from the oil pump feed could this cause some kind of oil starvation tot he VVT?

 

That was my initial thought also DD, regarding the tensioners, but that is strictly from a perspective, not experience.
Thus I would fear what Addicted is asking if you switched to spring tensioners and perhaps create a death blow?