Is there a DIY posting on the site WITH PICS, that show step by step the cable tie method of replacing just the secondary tensioners? I found one posting in the FAQ section with pics for replacing the entire timing chain set up, both primary and secondary along with all the hardware. There are several posts which spell it all out, but without the pics to back it up, I am a little leary about trying to do it myself. any help is appreciated.

 

I changed drive side three weeks ago,but didn't take pics.Plan to do another side two weeks later(spring break),will take pics if you can wait! It's not that difficult if you understand FAQ section pics.Remember:must lock crank and cams!I didn't lock crank last time,make me a lot of trouble.

 

I thought that with the cable tie method, you didn't need to lock anything ....

 

Right - No need to lock anything!

I'm in the process of changing the secondaries at the moment.
Did the right hand side yesterday, left hand side is on my list for today.

 

At least one of the pics I took...

 

I posted a DIY recently on Removing the valves to inspect the Secondary Tensioners with the related rails and guides.
Here is the link to view the PDF file:
https://www.jaguarforums.com/forum/a...4&d=1299472295

Jim Lombardi

 

thanks jim....i pretty much understand everything up to that point, its after that where I get a little confused. I am hoping to see where to cable tie the cam to lock it in place, and also from what I understand from reading other posts, you loosen the cam hold down bolts and lift one of the cams slightly to release the pressure on the chain to allow you to remove and resinstall the tensioner.

 

It's all pretty straight forward!

Once you removed the valve cover (and all the spark plugs), put a 24mm socket wrench onto the bolt that holds the big belt-pulley on the front of the engine.

Use the wrench to turn the engine clockwise (viewed from the front of the car) until the cam flats are ligned up to check for chain strech.
(If the cam flats line up perfectly, your chain is not streched.)

Turn the engine until the exhaust cam is in a "good position" to remove it.
(With "good position" I mean that no valves are pushed down completely by the cam lobes. At this position you'll have as less force on the cam as possible.)

Now put a Zip Tie through one of the holes in the exhaust cam sprocket wheel to secure the timing chain on the exhaust cam. (See pic above.)

Remove all cam caps EVENLY and in this process lift the cam by hand as you loosen the caps. Once there is a point when there's no more force on the cam at all. Now you can remove all cam caps and lay them aside. (Make sure the caps will come back on in the same order!)

Loose the tensioner bolts, lift up the exhaust cam, remove the tensioner bolts and remove the tensioner.

Clean the surface where the tensioner sits and put in/on the new tensioner. Push exhaust cam back in and place all cam caps back in place.

Now it is important to fasten the cam caps EVENLY to not to break the cam!
(I constantly whiggled and turned at the exhaust cam while fastening the cam cap bolts to make sure the cam turnes free and is not wedged.)

When the cam caps are all bolted on again, use the wrench to turn the engine slightly to get tension on the timing chain. Remove red pin from new tensioner and your timing chain should be good to go.
Now you can slowly turn the engine with the wrench to make sure everything is in place and your timing is right. (Check cam flats again!)

Thats basically it...


One additional hint...
The new tensioners need to get filled with oil to build up their full dampening quality.
Before you start the replacement, pull the fuel pump relais in the trunk (#4 for NA engines) and start the car. The engine will start, but die instantly.
After the removal of the tensioners, leave that relais out and crank the engine to get the oil pressure to built up and to get the new tensioners filled with oil. Put the relais back in and your car will start immediately.

(If you skip that process it is possible that the timing chain builts up that much slack that it will slip one tooth and you probably risk your engine!)

HTH!

David

 

Thanks for taking the time to explain it all David, it really seems to make sense to me now.

 

Just a small hint to anyone who is unsure as to how to tell the amount to turn a bolt before going on to another one:

when undoing the bolts, crack all of them just loose with your longer ratchet wrench, then switch to a box end wrench, and holding it close to the head to lessen the available leverage, undo a bolt only enough to feel less resistance and move to the next one. Repeat in cycles as the rising cam caps rise against spring pressure to take up the slack, until they are all loose, and then you can stop cycling.

when tightening the bolts, again hold the box end near the head for less leverage and tighten in cycles, moving to the next bolt in the pattern when have tightened some amount, for example 1/4 turn after you feel some resistance to turning. Once all caps are seated, then change over to a torque wrench and use multiple passes to achieve the specified torque.

The above is the very, very long way of saying "it's all in the fingers".

 

Question -- It has been a while since my engine rebuilding days - plus I never had an instance where I had to go in and just replace a tensioner.

But it looks like the tensioner is flat on the top without guides -- and the new one comes compressed. Why can you not just remove the old and slide in the new.

Obviously you can't -- just wondering why?

 

I initially thought or should I say hoped the same!
But even if you where able to fully compress the old tensioner - which is not possible as it is filled with oil - there is simply not enough room to get a tensioner out.
Unfortunately you have to lift the cam (just a little bit actually) to get them out and the new ones in.

 

In my research here on the site, I found somebody had posted a training tech manual for the AJV8 and V6 in PDF form. In the part about the timing chain and the seconday tensioners, it give instructions as to how to collapse the tensioner (ie. release the oil inside it) so that it can be removed.

"Insert a stiff piece of wire into the hole in the chain tensioner to release the check valve and collapse the tensioner"

If this is the case, might you be able to do the change out of the tensioners without having to mess with loosening the cam?

 

If you've gotten to the point you can do the secondary's you're over halfway into a full chain replacement. I just pulled the front off mine and every tensioner component has similar failures as those typically found with the secondaries. All of OEM components are the same plastic construction as the secondary tensioners (PLASTIC). Every chain guide rail I have has a minimum of 4 cracks in it, and the primaries appear to have fractures developing. If you've gotten the new metal secondary tensioners, you have an example of the upgrade that has been made in all of the components. The chain guides I have are Metal with a nylon face, and the primaries are full metal. Although it's a bit more work and more in parts to do the full job, I'd recommend it if you can. I've been researching this job for over a month and have found all the DIY documents and videos and based on what I've seen, if the the secondaries are failing, it is highly probable that you have failures further down. There is a great pdf (do a quick search) that will walk you through it step by step.

 

I absolutely agree with you bluerdg!

BUT, failure of the primary tensioner and/or the chain guides will not immediately lead to a capital engine damage.
But the failure of the secondaries CAN cost you an engine w/o any previous indication of an occuring problem.
One day you start your engine and BOOM it's toast.
With the failing primaries you'll definitely hear some kind of chain rattle.

So to keep the costs of mainteance low - for me - the replacement of the secondaries are enough to have peace of mind.

 

There indeed is a hidden back pressure valve which can be engaged by putting a stiff wire in the hole in the middle of the chain slip surface to eliminete the oil pressure in the tensioners. Nonetheless you won't get them out w/o removing/lifting the exhaust cam.

 

Gotcha....thanks to everyone for the information and feedback

 

Hi Bluerdg
I believe the PDF file you are referring to is Blackonyx Timing Chain DIY. I have included the link to that DIY in the Summary of Major Repair & Safety Issues (This is a sticky thread in the Jaguar XJ8 & XJR forum). Here is the direct link to the "XJ8 Summary at a Glance" PDF file: https://www.jaguarforums.com/forum/a...2&d=1298324822 . Click on the "XJ tensioners" button. When the new PDF page opens go to the bottom of the page. Under the DIY & Articles menu, click on the "Intructions & Illustrations" menu item. This will open the internet webpages for the DIY. The Blackonyx Timing Chain is 61 pages detailing each step of replacing both the secondary and primary timing chain tensioners, guides and other associated parts . It includes all the instructions and pictures to complete the full job.

Back in October we had "restricted performance" issue (tensioner failure). I printed out the 61 pages in our color printer. After the case cover was removed we noticed the secondary tensioner had a crack and the primary guides also had cracks. I had our mechanic replace all of the secondary and primary timing chains, tensioners, guides, etc (a full replacement of all the parts except for the sprockets). I made sure he read all of the 61 pages and asked him to use the DIY as he would use a repair manual. I rented all of the specialised tools. He completed the project without a problem. I am sorry there are no pictures taken of our own repair. I went on vacation before he actually started the major teardown and reassembly. Completed the job in about 12 hours total.

 

South-thanks for starting this thread. Prior to this I did not know about the zip tie method, and while I downloaded the pdf Jim talks about, I knew it'd take me a couple of days to work through it. The zip tie method sounds like the ticket for me.

 

Hi
I found this Roadfly forum thread entitled "Timing Chain Tensioners - An easier way to replace"
Author: maxwdg on 2009-06-03 at 03:52:24 wrote this procedure and looks like he completed it successfuly.

One look - is all it took for me to acertain the easiest and totally safe proceedure of getting at the secondary tensor removed - with out all the paranoid crap that could have been endured.

I Simply removed all of the bearing caps of the exhaust cam and had a buddy lift it up just slightly (keeping tension on the gear and chain, being careful not to let a gear jump while I just reached in a pulled the stupid (and cracked, nylon second gen tensors) out, ploping the new aluminum units into place.)

I then re-oiled and retourqued the the cam back into its saddles. Did it within minutes per side! It took me more time just me being particular about sealing the cam covers and cleaning as I went - than the whole of the replacement of the secondary tensors itself!

Finished both side in less that 3 hours!

Guys This is NOT a complicated operation! its a piece of cake man! Just do it yourself! Note: End of the part I copied from Max's posting.

My comments:
I like to know what everyone thinks about how safe is this method that Max used. It is the only reason I have put it in this reply posting. Note: I only made format changes in the above paragraphs so it would be easier to read.

Here is the PDF file of Max's posting in Roadfly:
Timing Chain Tensioners - An easier way to replace - Roadfly.pdf

Jim Lombardi