Hi
I need your help , I bought 2001 XK8 with 106K miles as none runner, the owner told me he pulled out of driveway of his house he heard noise from engine, he stop the car, towed to Jag dealer told him it needs new tensioners and chains, at cost of $4100!!! He told me all tensionser where replaced 6 month ago by another non dealer shop at cost of $2700 but the shop did not replaced the actual chains!!! Anyway shop is out of business and he can't go back to get his money and he did not want to fix the car either So he sold it me .
I bought the car knowing the problem got the car home , I thought at worth I replace engine and hopefully it would not too bad, finger crossed!!! ,took the covers out and notice secondary tensioner on the on passenger side is broken. but no damage to upper tensioner , and no other damage that I could see ,( but have not look into lower tensioner yet) Also missing is chain clip. Not sure where it is it could be???
I looked into all the pistons with the bore-scope and appears none pistons damage or broken ( don't about the valves) Also timing cams it seems little off. ( due to the flat spot of the cams are not parallel to surface of the head nor even to each other. I am planning to rent Timing alignment tools, but have not ever used these, it would be first.

Here are my questions
1) I know I need to off the timing over to investigate. also find the chain clip that is missing, How could I check for bend valves if any? I really don't want to take the head off, unless I have too.
2) Do I need to change the all the tensioners again even they are new style no damage to them?
3) How can set timing on the cams since they are off I think by tooth or two not sure.
4) How can I bring to TDC?

Since I have limited $$$ I really don't want to take to shop, so far I am willing to do most of the work my self.Any help it would be great. Thank you.

Joe

 

Now let me first say, I'm no expert on this, but here's my limited input.

1) I would do a simple compression test. If you have bent valve stems this should show it. However low readings on various cylinders may be other causes.
2) Common sense would say no. I would follow common sense here unless there are other factors that may support doing something.
3) Normally it required retiming, removing the timing chain and replacing it in the right timing position. I would also find and correct the reason it apparently jumped the notches.
4) I would think the TDC could be determined with a factory mark on the engine damper at the front end of the engine crankshaft.

So, there you have it, an educated guess. I wouldn't take to the bank though!

 

Can you clarify, is the tensioner broken or not?
Vector

 

Please do not attempt to do a compression test with suspect exhaust valve timing issues!

Cam timing is not done at TDC. I think it is 45 degrees past tdc but the correct method is to lock down the flex plate at the marked timing point. All this is covered in one or more of the many tensioner replacement threads.

Correctly timed the driver (left) side flats are very nearly parallel and the passenger side are tilted down to the center by a few degrees.

If, indeed, you have chains with chain clips they will probably be found in the oil pan. They will probably not go anywhere from there.

If you have the metal tensioners I would not replace them as we have never heard of a failure there. One suspect issue is to verify that the tensioner bolts have been replaced with the shorter ones required by the metal tensioner bodies. The new ones are about an 1/8" shorter and using the original will bottom out before sealing. The result in an oil leak between the head and the tensioner resulting in loss of pressure and failure of the whole reason for having tensioners.

 

Thanks you for the replies, well Test point I am with you I did not attempt to do a compression test .
I start taking thing a part, the tensioner are in one piece the upper one at least, I need take timing chain cover to the rails and other ones. after reading your reply and looking at cams it makes sense, the driver is very nearly parallel and passenger side , the flat spot are nearly parallel to each other but the flat spot facing toward fender. as far chain clip, I am not sure I guess once I take cover and drain the oil I am hoping to see it.
I do have metal tensioners, but I am not sure if the bolts are were replaced, how does one find out it they were or not?
As you were saying "The new ones are about an 1/8" shorter and using the original will bottom out before sealing" I need to see it in the morning , I am planning to take photos and post it may it would be help, again Thanks

PS will leak down test tell me if there is any problems with bend valves?

PSS how does one post photos?

 

On mine with the left bank flat the right was tilted to the center between the cams. I interpret your comment to say that the intake cam is tilted correctly and the exhaust is a tooth or two off facing out, not in.

A leak down test will, indeed, comment on the condition of the valves.

Perhaps someone will measure the new/old bolt length for you or quote a spec.

On pictures; below the reply area you will find a 'manage attachments' box. Click that and browse/upload your pic to forum storage. Copy its storage location. Use the 'picture' (mountains) icon above to load your storage location. Someone can probably give you better directions but you can probably figure out how to make that work.

 

One way to tell if you have the correct bolts is to see if the tensioner base is completely flush with the mating surface. Another is to lightly screw the bolt into the head after removing the tensioner. If the distance from the mating surface to the underside of the bolt head is at least 1/8 inch less than the depth of the hole in the tensioner, it is the correct bolt. All 4 bolts are the same.

JEPC lists the bolts as M6x35mm for the 4.2 engine found in the X350.

Some of the aftermarket guys supply ordinary M6 bolts, but the originals are flange heads to spread the load better and prevent gouging.

 

If it helps there's a sticky on posting pictures which expands test point's instructions
https://www.jaguarforums.com/forum/j...es-2418/page3/

 

A quick compression test can be performed IF the broken chain and all pieces are removed as well as the exhaust cam. The spinning intake cam will allow air into the cylinder but there will be no air out the exhaust. You should still get a reading of some compression or NONE!!!!!

IF ZERO in any cylinder then proceed with HEAD OFF.

There is a 50/50 chance that the exhaust cam stopped in a GOOD place and no valves bent.

good luck

bob gauff

 

You have plenty of good advice. If I were you, I would replace the tensioners, and chains and clean out the oil pan. I would not want to try to guess which part might fail or which ones are good enough. You want a good reliable engine. Fix it right.

 

Thank you for the input, I am planning to drain oil and remove oil pan and clean things up so make sure thing are A ok, here are some more questions

1)replacing tensioners are they necessary if they are not damaged and they are later model?
2)Can any one tell me how to leakdown test?
3)Which test is better compression or leakdown test?
4) I understand I need to bring to TDC , out the pin in fly wheel to locked , I was told I need to remove CPS out then put the pin in, where is the CPS?
5) which way to rotate crack?

I called and Christopher's Foreign Car parts, rented the pulley puller and timing Alignment tool set, I talk to him for few minutes and he seems to be good guy and knowledgeable. I did not ordered any parts yet , I want to take take timing cover out to see before I order. Again Many thanks for the input and your help.

 

I've edited your post so that the pics show up in the post.

You are going to have to remove the cams so that all the valves are closed before you make any attempt to rotate the crank.

 

Hi everyone, I remove the exhaust cam since chain link came loose , was getting ready to do leakdown test, I notice all valves seems the pop back/close except one cylinder, I am not sure if valves in that cylinder bend or???? can someone give me advice, again I really dont want to remove cylinder head before I making sure I done all I could. I took some photos to give more idea, Thank you again

this photo shows correct valve position


this is valve that is suck in open position

 

Others may have a different opinion, but if the cams are out, and the valve stays open ... bent valve or valve seat popped. Most likely bent valve because the chain came apart. Then again, if the seat popped, it could be the cause of a lot of chain flapping which could lead to a split chain coming apart.

You can find pictures of the location of the CPS and the locking method in some of the tensioner threads. And, it is not at TDC.

The leakdown test is the only safe test, and a compression test cannot be done with the cames out. Punch leakdown test into a search engine ... someone out there must have a writeup.

BTW, don't use split chains this time around.

 

It's unfortunate that split chains don't work on the Jags. Many years ago I had a couple of Alfa's and there did not appear to be a problem with the chains. Maybe it's just a quality issue with the currently available chains.

 

I'm with the others, most likely a bent valve. :-(
A split chain wouldn't be my first choice, but I don't understand why they wouldn't work. My guess would be that someone put the spring clip on backwards.

 

The split chains I have seen in some kits come with a link that must be 'peened' to keep the end plate in place.
There is no clip for the master link so it looks like all the other links when assembled.

The link is actually from a Mercedes oil pump chain.

bob gauff

bob gauff

 

Here are a couple of links to JTIS head removal and Jaguar engine repair training manuals. With the flex plate alignment tool in place and the cam alignment bar bolted down there is little way to screw this up. You do have to pull the front cover off to remove the head. General caution: do not attempt to use the flex plate alignment tool to hold the crankshaft while removing the harmonic balance pulley bolt. You will destroy the flex plate doing that. The rope trick works well. While I haven't had to do this it doesn't seem very complicated or any more so than any other engine.

Head removal thread:
https://www.jaguarforums.com/forum/x...ad-help-67056/

Engine repair training manual: Engine Repair Course Code 168.pdf

 

I've never seen one! So, after removing foot from mouth I'd say that if they are peened they should certainly work, the most likely cause for failure would still be operator error IMHO.

 

Is it weird that I'm reading this thread and thinking "I WISH THIS WAS MY CAR!!!"?