First generation was plastic. Second generation was plastic with an external spring assist to reduce the signature 'rattle' of a failing tensioner. Third generation was metal. Actually, the tensioners went through at least 21 part number revisions from '96 to '03.

 

Does this mean that if a 2nd gen tensioner fails and is dangerous, that the noise will be concealed/hidden to make it harder to detect one'e engine is at risk?

 

You would have to be deaf to miss when the cap comes off. You can hear the chain ride metal on metal for a bit before it fails.

Once a client came driving in with that noise, chain broke at the corner next to my garage, bent valves.

Only once, a client started their car and the way the plastic cap went through caused the secondary chain to hit the cylinder head and it broke immediately

 

Does this look like the updated tensioner? Took the risk and purchased a 99 XJR wrecked for whatever reason and I opened the valve cover and found the tensioners weren't plastic, but metal/aluminum looking.

 

Yes, that is the metal tensioner.

 

Would i need the entire timing tool kit If I'm just swapping 1 intake cam shaft on my engine? I was thinking maybe the camshaft locking plate and flywheel locking bolt is the only necessary tools needed to accomplish this job?

 

Actually Donzi you are right. You don't need the tools unless you are changing the chains and the front bottom guides as well as the chains. That's what the tools are made for. If you are just changing the upper tensioners you can loosen the bolt on the cam closest to tHe fender, just so we don't get confused here, but before you do that use two large wire ties to hold the chain to the cam sprocket. That way when you move it just enough to get the tensioner out the chain doesn't move from its correct position. Then you can slide tahe new one back, put the cam back down, put all the bolts in place including the cam caps and torque everything thing down. Typically 14lb. They are using this same method if you only want change the upper tentioner at the Jaguar shops now. It easier, quicker, and keeps everything in time. Oh yeh, don't forget to cut the wire ties off!

 

My gosh! What a thread. I will throw in that I did my secondary tensioners with the zip tie method about 9 months ago with absolutely NO problem. That was the first time I did it. I did use a long breaker bar to hand turn engine to find the spot where all tension was released to the valves of that bank before I loosened the cam caps.

Got the tensioners from Ford for $ 61.00 one side and $ 64.00 the other (curious?). Gasket was about $ 50.00. Took this first-timer less than 5 hours.

https://www.jaguarforums.com/forum/m...nsioners-8182/

 

I changed the timing chain tensioners on my 99 xj8. Didn't help any, because all the valve seats except 6 of them had all floated, causing a piston and valve to collide, punching a hole in the piston, broke the spark plug and one of the valves.

 

wow , i'm amazed this thread is still going ,

i first posted this back in 2007 , and back then no one did the zip tie method, in fact only about three peeps had changed them DIY fashion at all


BB

 

Even this late date, this has been one of the most valuable threads on the forum. Saved me over a thousand dollars, alone.

 

Yep, it saved me who knows how much money and trouble. My tensioners were cracked up the middle like most. I sleep better now.

 

Any truth to not having to change the tensioners if your XK8 is 2005 or newer? Jag changed the tensioners to be automatic & metal construction I read in the same article.

 

I was wondering the same thing since I've seen it other places and haven't heard of the locks until now. I don't have a Jag but I'm thinking of getting an XJR with 53K on it and I doubt that tensioners have been done yet...doh...

 

tensioners do not need to be changed because they are made from metal after 2002 , as they were standard fit to the 4.2 V8 , which was introduced at that time, most of the last 3.2 and 4.0 AJ27 units had them fitted around that time as well




BB

 

Brake Buster and All, I feel like I'm flogging a dead horse here but inquiring minds want to know.
I have a 2000 and Dave and others in the area have tensioners to be done, now or down the road. The tie method has and is of course proven to work and I see no problem doing it except for the many cam bolts and caps being moved.
My question is, since I have one set of locking tools, would it not be easier to lock the one side, undo the front sprocket, move to the side while sliding out the old, in with the new, sprocket back on, rap it up and do the other side. Would this be a good or bad thing????
Maybe put a tie on just to be safe.


Thanks, Wayne

 

He's talking about the "zip tie" method which is well documented. The chains are zip tied to the sprockets, and then the cam tilted up from the rear.

If the chains remain in a constant relationship to the sprockets, the timing cannot change. Can't - as it it's impossible.

 

The tools are necessary if you are upgrading/renewing primary and secondaries. The pros on this forum are purists (as they should be to be most helpful for us DIYers) and believe doing just secondaries is wrong. From the beginning of this thread, and the many others related, you will see the argument for and against the tie method and use of the tools. But, if you select the zip tie method, first assure alignment of intake and exhaust cams, then turn the engine to the point with the least spring tension on the exhaust cams. Zip tie it without unloading cam tension almost assures a broken cam shaft at start up. And a careful reading will show many other keys for success. Way, way back a forum member noted PATIENCE IS THE MOST IMPORTANT TOOL YOU HAVE.

 

All, I know that doing the complete upper and down, chains, the full lot, would be the way to go, time and money being no problem. The upper (secondary) has been replaced multiple times and has enable engines to continue to function for a extended period of time by correcting a design flaw. I understand it's a band aid before major surgery and getting approval from someone that has to guarantee their work is asking too much. I just need to know if the locking tool on one side with a tie will keep things in alignment. I'm trying to keep from getting anything wacky on cam caps or bolts, not that it's anything major, just been there done that, sort of thing.


Thanks, Wayne

 

Thanks and Mark SF confirmed my thinking. I will post on the results. Locking the one bank with a tie on the chain has got to be a good way on the secondary. I hope!!!


Wayne