I Know it's been said..but! Change those tensioners!!
#1
I know it's been said..but! Change those tensioners!!
Thanks to the help of one of the members here and the great info on this site I tackled changing the tensioners on my 2001 XJ8L today. And yes like a twenty dollar hooker,there was crack involved! I have attached pics of the tensioners. The left bank had the normal crack in the body. The right bank had crack in the body,and yes that is the metal the chain was running on! I found part of the plastic part of the tensioner wedged below the chain. Last pic is of everything put back together. Car was running fine, no noise what so ever. Just hit 100K.
Last edited by 1Jaguar1; 08-06-2009 at 05:25 PM.
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davidladewig (03-11-2021)
#3
Hi Jean-Karim,
It was my understanding that the improved tensioners were on the 4.2 engines. The late 2000-2001 4.0 engines fixed the problem with the Nikasil cylinder liners which had a tendency to go bad. The other design issue I am aware of for the 4.0 engines was the water pump. Jaguar World, among others, recommend that the 4.2 tensioners, as well as the later design water pump be retro-fitted on the earlier model 4.0 engines. Some of the Jaguar technicians who frequent this site might be able to shed more light on the subject though.
Mike
It was my understanding that the improved tensioners were on the 4.2 engines. The late 2000-2001 4.0 engines fixed the problem with the Nikasil cylinder liners which had a tendency to go bad. The other design issue I am aware of for the 4.0 engines was the water pump. Jaguar World, among others, recommend that the 4.2 tensioners, as well as the later design water pump be retro-fitted on the earlier model 4.0 engines. Some of the Jaguar technicians who frequent this site might be able to shed more light on the subject though.
Mike
#5
I have a 99 xk8. I believe the engines are the same. Did you pull the timing cover and all of the or did you do everything from the top? By that I mean remove the valvue covers and remove the two bolts holding the tensioners and pull them out. Assuming the cams would not move and slip in the new ones and pull the pin?
#6
#8
So if can simplify your instructions a bit.
1) You lock down both cams across the flat area at the front of each cam.
2) Them by loosing the cam sproket on the exhaust cam this will give you the clearance required the remove the tensioner?
Is the sproket on the exhaust cam indexed in any way so the alignment won't get screwed up? Or would you not really loosen it up enought to matter? Is the exhaust cam the one without the timing chain, or the lower cam?
How long did it take you after you had all of the "stuff" out of the way to begin the replacement. If I feel I can do this, parts are parts. Heck if I can replace a clutch on a toyota 4x4 how hard can this be. I'm just trying to budget my time to keep from having a melt down.
PS: trivia there are 180 bolts to remove while replacing a toyota 4x4 clutch. My wife asked me and I counted them off in my head. Crazy the silly things you remember.
1) You lock down both cams across the flat area at the front of each cam.
2) Them by loosing the cam sproket on the exhaust cam this will give you the clearance required the remove the tensioner?
Is the sproket on the exhaust cam indexed in any way so the alignment won't get screwed up? Or would you not really loosen it up enought to matter? Is the exhaust cam the one without the timing chain, or the lower cam?
How long did it take you after you had all of the "stuff" out of the way to begin the replacement. If I feel I can do this, parts are parts. Heck if I can replace a clutch on a toyota 4x4 how hard can this be. I'm just trying to budget my time to keep from having a melt down.
PS: trivia there are 180 bolts to remove while replacing a toyota 4x4 clutch. My wife asked me and I counted them off in my head. Crazy the silly things you remember.
#9
daddyo007,
The cams have to be locked down so you can loosen the bolt to the cam sprocket and not effect there position and timing. The sprocket it self has no index I noticed for replacing on the cam. When you remove the bolt,which is long by the way,the sprocket with chain can then be moved forward. I used a large screw driver working the top and side of the sprocket to move it forward off the cam as the chain is tight. Once off the cam you can hold the sprocket easy enough in one hand while putting the new tensioner in with the other. I used a zip tie in one of the holes,not used by the sprocket tool, to secure the chain and sprocket together just to make sure nothing would move or fall while working with the tensioner in the other hand. I also recommend taking a clean rag and stuffing it in the area under where the pins will be that you have to pull out of the tensioners to help insure if they fall they won't disappear in your engine. Total time for me was 6 hours start to finish,but I probably wasted 45 minutes to an hour of that detailing my engine, replacing hoses,washing out the airbox etc.. so it could be done in 5 hours I feel. To answer your one question,once everything is out of the way,it's only 10 minutes to change the tensioner it self. I have a 2001 and did the job without a service manual. Just read the write up by one of the other members. The one part that took the longest to get out of the way on my car was the oil dipstick which is double nutted with one of the valve cover bolts. Took a little time to work the bracket attached to it out of the way safely so I could remove the valve cover nut behind it.
The cams have to be locked down so you can loosen the bolt to the cam sprocket and not effect there position and timing. The sprocket it self has no index I noticed for replacing on the cam. When you remove the bolt,which is long by the way,the sprocket with chain can then be moved forward. I used a large screw driver working the top and side of the sprocket to move it forward off the cam as the chain is tight. Once off the cam you can hold the sprocket easy enough in one hand while putting the new tensioner in with the other. I used a zip tie in one of the holes,not used by the sprocket tool, to secure the chain and sprocket together just to make sure nothing would move or fall while working with the tensioner in the other hand. I also recommend taking a clean rag and stuffing it in the area under where the pins will be that you have to pull out of the tensioners to help insure if they fall they won't disappear in your engine. Total time for me was 6 hours start to finish,but I probably wasted 45 minutes to an hour of that detailing my engine, replacing hoses,washing out the airbox etc.. so it could be done in 5 hours I feel. To answer your one question,once everything is out of the way,it's only 10 minutes to change the tensioner it self. I have a 2001 and did the job without a service manual. Just read the write up by one of the other members. The one part that took the longest to get out of the way on my car was the oil dipstick which is double nutted with one of the valve cover bolts. Took a little time to work the bracket attached to it out of the way safely so I could remove the valve cover nut behind it.
Last edited by 1Jaguar1; 08-13-2009 at 12:01 PM.
#13
Join Date: Mar 2008
Location: Powell, Ohio U.S.A. 43065
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Hey Jean,
The point is that you have plastic tensioners in your car. You can wait until they fail before you change them, which may result in a breakdown if you are lucky and a destroyed engine if you are not.
Or you can change them, even if they still look perfect. They are not going to stay that way. There is no guideline for their life expectancy, some have failed as early as 30K miles and many will last past 100K miles. I have seen three engines destroyed as a result of failed secondary tensioners that were towed to my shop: 72K miles, 96K miles, 105K miles.
The point is that you have plastic tensioners in your car. You can wait until they fail before you change them, which may result in a breakdown if you are lucky and a destroyed engine if you are not.
Or you can change them, even if they still look perfect. They are not going to stay that way. There is no guideline for their life expectancy, some have failed as early as 30K miles and many will last past 100K miles. I have seen three engines destroyed as a result of failed secondary tensioners that were towed to my shop: 72K miles, 96K miles, 105K miles.
#14
#16
#17
Daddyo007,
I sent you a pm regarding the tools. I would never reuse a gasket. For the money and time,it's just not worth it. The pm I sent had all the info on where to get all the parts the cheapest and how to get free shipping. As far as the specs,go to the tech section and pm Christo for a free download of your service manual.
I sent you a pm regarding the tools. I would never reuse a gasket. For the money and time,it's just not worth it. The pm I sent had all the info on where to get all the parts the cheapest and how to get free shipping. As far as the specs,go to the tech section and pm Christo for a free download of your service manual.