Chains "stretch" or get longer due to wear on the pins, rollers and links. Chain tensioners take up the slack(on the non-pulling side) more and more as the chain grows. A new, tight chain doesn't even need a tensioner. A badly stretched chain does not lay down smoothly or tight on the sprocket. A stetched chain can jump a tooth when the engine is first started and the tensioner is not yet "Pumped-up" by the oil pressure. (As mine did at 75k miles without any warning) Just being off by 1 tooth makes the car run like crap. If this is the secondary chain ( as it seems is most common) The intake cam will still be timed but the exhaust will be way off. It is relatively simple to replace the chain with a new one (that has a master link avail from a few suppliers) and replace the plastic tensioner at the same time. Timing is simple with a cam locking bar and the flex plate (flywheel) pin. You can make these tools easily.
All you do is lock the crank at TDC #1 (which should bring the intake cam to where the flat is parallel to the head surface) and position the xhaust cam with the flat parallel to the head surface. Now you lock the ex cam to the sprocket with the 10 mm allen bolt. I dont see any way you can change the intake cam which may be off slightly due to primary chain stretching. If it's off more than a few degrees you'll have to dig deeper! (under the front engine cover. See FAQ for tool descriptions/dimensions.
BTW I was able to use an L shaped 10 mm allen wrench with a cheater bar (pipe) to loosen/tighten the exh. cam locking bolt.

 

Just did the tensioners.
Thanks to All of you.
Great advice in this forum.

Treat each side as a separate engine. Works well!
found a few little secrets:
1. As stated you don't need to "pin" the flywheel where the crank sensor is.
2. A 1"x 3/4" bar of aluminum with holes (don't need the legs) drilled as by Hellhound (Great Job!! Thanks!!) as in his drawings:
https://www.jaguarforums.com/forum/x...q-37415/page5/a>
3. McMaster Carr has the Aluminum bar. Here is the website:
a. McMaster-Carr
b. Dimensions and p/n: ¾” x1" p/n= 89215K432 $22.59
4. The bolts Ford sold me were too long, so I had to machine off the original bolts by .222". Measured the bolt depth in the old one and the new ones and the difference in the thickness of the tensioner body and it worked out to be .222".
5. If the little oil pressure relief ball does not release, it is a bear to get out.
6. The sprocket removal is so simple to do compared to remove the cam shaft caps and leaving the sprocket hooked up. Hellhound's spanner wrench is good so make your own.


1"±0.003"89215K432$22.59

 

I am 1/2 way through changing mine out using the zip tie method(I am taking a break to check tightening specs on here). Thanks for all the pointers from all of you. It was a huge assist in doing this job. FWIW mine is an 03. Until this evening, I thought the tensioners needed to be changed on all of these engines. Mine were the metal ones (That I removed), and looked real good with 130K on them. (according to Jag records, they were never replaced) I'm putting in the new ones regardless. Thanks again!!!

 

I orderd this Item at 1:07 pm EST qnty 2, and they said it would be here by tomorrow. now that is service, and free shipping. thanks for the info.

 

Just wondering, how bad off do you think these flats are? and when you make them parallel to the head, your talking about the intake cam flat aligned with the head and #1 at tdc? then get the exahst cam flat in line with the intake by putting the cam lock down tool on ? and with this done, the timing should be in the right spot? Just double checking. thanks in advance.

 

Yikes...do not run the engine like that...you are at least one, maybe two teeth off of alignment.

 

I was afraid of that, so the next step would be to lock the crank, Loosen the cam gear to get the exhaust cam to line up with the Primary cam ? then lock them both down? re tighten the gear ? Just not sure if this Procedure has been covered in this thread yet, being that the cam flats are so far off.

 

Looks like you are in the nick of time.

You got in before me! Yes, you'll need to set up from scratch, lock the crank then set the cams correctly.

Check here for the procedure http://www.mediafire.com/?z4jxec2avzn50zn

 

Yes, but might as well wait until you have the new tensioners to put in.

Although it is a lot more work, you might want to consider a new chain for peace of mind since this one has been stressed, although I would not make that investment until I determined there was no engine damage (piston/valve collision) in the first place from the skipped sprocket(s).

 

Well the tensioners from Christopher's place came in today, that is why I have shots of the heads without the valve covers on them, the car ran fine, until I got back from a 93 mile trip, was driving around and felt like 2 cyl started missing, drove it 8 miles home. jacked it up and disconnected the battery. took the valve covers off and here we are, so you think I should do all of the chains and guides instead of just doing the secondary kit which has a chain with a master link in it, gaskets for the valve covers and two metal tensioners? am also waiting on the cam lock down parts and just ordered the crank lock down tool.

 

this is what the driver side tensioner looked like , bare metal. chain slack.

 

Personally, I would shy away from an aftermarket chain (masterlink or not) unless you were absolutely certain of the quality of the aftermarket part. If that chain fails you have serious engine damage on your hands.

With the car in your condition, I would do a complete (primary and secondary) timing job if I was keeping it for the long run....but again not until I verified there was no damage caused by the secondary tensioner failure first.

 

well at this point, I have the v covers off and will do the secondary tensioners, put it together and see how she sounds. I really do not know how to check for any damage other than to turn the crank and listen for something that sounds like a a bunch of keys in a empty metal lunch box. any suggestions would be of great help. like I said before, it ran fine, then sounded like it was missing, drove it home, and turned it off. has not moved in 3 weeks now, I have been reading threads on this forum and orderd the tension er kit from christophers, it came today, but now have to wait for the tools, so I am sure it will lead into next week. I really would have thought if there was internal damage that the car would have made other sounds while running other than just two cyl missing, when I did pull the plugs from the driver side I had noticed that the spark plugs looked like they were never changed and the coil packs were original too, the rider side had been changed, coil packs and spark plugs . they looked new, the tensioner was plastic on that side but showed little ware, how ever, the cam flats are worse on that side with a tight chain vs the driver side with tensioner down to metal, and bad plugs and coils. go figure.

 

If yiou button her up after the secondaries are done and cams are aligned and she sounds and runs good and has no codes she is probably OK and you can be thankful for dodging a bullet.

At that point doing the chains and primaries could be consdered non-emergency preventative maintenance.

 

thanks for your Time and Information, I will do exactly that and keep my fingers crossed, this is just a warm up for the complete timing primary, secondary, waterpump, thermostat housing, chains, guides, etc.. full front of motor re build.

 

I think that is the best plan of action, you wouldn't want to try and do any kind of testing for compression etc until you get it back in time.

 

Just a note, as I was turning the Crank Bolt that holds the pulley in front of the motor, observing the position of the exhaust cam in relation to the intake cam, I noticed that the exhaust cam would move continuously as the intake cam would not start to move until I had at least a quarter turn of my ratchet, shouldn't they both move at the same time? all the time? and if so, what has happened to make the top cam not move along with the gear and chain attached the intake cam? any clues? here is a link to the video of it. cams - YouTube

 

I do not have this on my XKR which does not have VVT, but I suspect it is probably the variable valve timing (VVT) mechanism.

 

If that is the right bank, I think you are turning in the wrong direction, or maybe I shouldn't have had that second glass of wine with dinner. The right bank tensioner piston acts on the lower part of the chain, and the exhaust cam has to move with the intake if you rotate the crankshaft clockwise as seen from the front.

 

The intake is on the top.