Tensioner question
 

I recently obtained a 2000 XK8 which, as beautiful as it is, appears it will ultimately be more expensive than the other Jags I own. I fully intend to have the third generation tensioners installed, since I didn't get records & have no idea whether the issue had been previously addressed. After that, I'll address the roof hydraulics.

My question is: should the timing chains be replaced, as well? Or is changing the tensioners sufficient? It presently has 96000 miles on the odometer. It runs smoothly, with no particular rattling, or other objectional noises.

You will not need to replace the chains unless the plastic shoes are missing and the chains are worn from rubbing on the underlying metal. You can do this replacement yourself for under $200 if you are at all handy with tools.

Thanx, R.J. (which also happens to be my initials!!) I am adept with tools and being under the hood. I've already found the sticky, with pics, giving the step by step replacement destructions, er I mean, instructions. :icon_wink:

Ray

Welcome to the forum. The following link will take you through the changing of the upper tensioners with pictures. My 2000 XK8 had 40K one it and they had just started to crack. At 96K you are pushing your luck if they have not already been changed. Don't and I mean don't delay in at least checking by removing the right cam cover and checking.

Have fun doing the job. And read as many other posts as you can find. But if you do it the way I did it I think you'll like it.


https://www.jaguarforums.com/forum/x...ics-how-52653/

Thanx, EZ.
I had previously found your above post, and had already been studying it.
While I didn't get maintenance records, a CarFax report indicates the valve cover gaskets had been changed in 2007, so I'm guessing the tensioners were, at least, inspected at that time.
Ray

Sorry I'm late responding to your last post. I only hope I'm not too late. If there is nothing in the maintenance records on this 96,000 mile car about tensioners you must assume the tensioners have not been changed and you are dealing with a time bomb that could cost you more to fix than the car is worth. You must check or have a good indy guy check to see if they have been changed. The cost would be minimal to remove the right side cam cover and look. If the tensioner is pink plastic like in my pictures both must be changed NOW!!!!! The tensioners could fail the next time you start the car if the plastic one have 96K miles on them. Some one inspecting the tensioners some time in the past means nothing and I mean nothing. Depending on the miles when the cover was remove and an inspection performed by someone that was not aware as how they fail they would look OK. When I removed mine at first I thought they were fine until I noticed the cracks starting. These cracks were not noticeable before removal.

I think this is the best advice you will get on this subject. Last one I know of that failed in my area cost $8,500.00 to fix and that was four years ago.

Please keep me informed.

Don't count on it. My guess is the valve covers were done along with the spark plugs as the plug recesses were filled with oil. Mine had all the tensioners replaced but never had the valve covers or spark plugs done at 85k.

Hi Shara38, It really helps us here on the forum to hear back from members that we have given advice to. So please come back and tell us what you have decided and what you have found following any inspection or rework.

Follow up helps us all and encourages us to do more.

If you see any wear on those tensioners, It would be best to change the 4 chains and all of the tensioners, Just for a piece of mind

Thanx, EZ. I've ordered the entire chain kit. I worked for an excellent indy 10 years ago, & he'll be doing the installation. On his advice, together with my propensity to keep a vehicle for extensive time (I've had the XJ40 for 13 years), we decided to replace the all the chains, tensioners, guides, etc., and I figure it'll be a good time to replace the water pump & thermostat, too. The water pump ordered has the metal impeller. But that leads me to ask, is the plastic thermostat housing also a weak area that should be replaced during this teardown? Also, is the orange anti-freeze a necessity, or, would a thorough flush and fill with the green anti-freeze work just as well? I ask because I already have a case of anti-freeze, that otherwise, I probably will never use. I know the 2 types are not compatible.

Thanx
Ray

The thermostat housing is subject to aging, as is the connecting pipe. If you decide on the aluminum housing, be aware that there are some poor quality ones on the market. Mine was from Welsh Ent. and is excellent.
I know there has been lots of discussion and warnings about changing antifreeze type, but my own opinion as a chemist is that if you do a flush changing to yellow or green is fine. I'm using it in both of my cars.

Thanx, RJ. After my post, I found the sticky about anti-freeze. According to that thread, my VIN places it clearly in the orange anti-freeze type. Either way, I'm going to thoroughly flush it.

Yes...change out the thermostat housing with a metal one now. The composite plastic will deteriorate, and though it might not go out on you anytime soon, chances are it will go out on you at the most inopportune time (I think we can all relate to that).

Mine went out 2 years ago on a 118 degree day here in Phoenix.

yes change tensioners all of them, thermostat housing to medal and make sure you put a new thermostat in of course. also change the water pump to the new upgraded generation that will work so good for the car. also drain that coolant out of the bottom and go get two gallons of new coolant not blended but the real coolant. Don't forget to check that oil pressure sending unit while you are changing those tensioners. drop that oil and change the filter. that car should run like a dream after all of that. Me my self I still have to change that coolant overflow bottle because I get low coolant warning but my coolant is at a good level. its the sensor that get stuck in those things. and I need to change that brake module. these are beautiful cars

I went to the local auto store and bought the orange coolant. It was Preston for GM. But on the back it said also for Ford and the specification number was exactly the same as specified the the owners manual.

OUCH!!!

Thanx

The orange coolant widely available is also known as Dexcool.

The only reason I was asking about which coolant is that I already have a full case of good old green Prestone & just wanted to use the supplies already at hand. On the other hand, If I flush & fill the other 3 cars in the coming year, all the Prestone would be used! :icon_pumpking:

Boy, am I glad I took your advice. Go go the other "tensioner" thread for the pic of the ***** that came out of an engine that was running well, with no unusual noises. Seems the prior owner(s) did the absolute minimum in repairing items that arose, and not even basic minimum maintenance.

https://www.jaguarforums.com/forum/a...ming-parts-jpg

Why would yu want to put Dexcool in with all its history of problems with eating aluminum and gaskets??? There are many better choices out there now. The universal yellow is just as good without the live critters and issues with other coolants.

If you use Dexcool for the first time make sure your
block and heater core are also flushed.