Oh yes, I've heard of it before. A common failure on old Mercedes is the vacuum pumps to go out releasing its bearing ***** all over the engine. A few of those jam up somewhere and its goodbye engine. I think this is unusual because the tensioner fractured enough to send bits into the engine but not fail completely to the point where it started jumping teeth.

I'd suggest buying a service manual (CD or hardcopy) and you and your uncle can be helped along with it. Might as well arm yourself with as much info as you can.

 

chinny
Do you know the date code for your MY 02? The cars buily after August 01 had metal tensioners, so foy yours to have come apart would be a significant piece of information.

 

How would I obtain my date code? I don't even know what that is. I can supply my VIN if that helps.

 

The manufacture date should be on a label on the driver B column. Sept or later '01 should be metal tensioners. Any dealer can use the VIN to produce the engine serial number. That serial number is in the form of yymmddhhmm providing the engine assembly date. The conversion to metal tensioners occurred August 13, 2001.

 

There should be a white sticker that's visible when you open the drivers door, the build info will be on that.

 

[quote=JagScott;307723]Something I am noticing with the tensioners, is they can cause problems even if they are the metal ones. As Chinny said, a piece of the tensioner fell into the oil system and clogged one of the bearing oil channels, which eventually ruined the engine. The new tensioners, although metal, do have a plastic piece on top of them that will be worn down by the timing chain. It will eventually fall off the tensioner and go down into the engine. Not only can the plastic cause trouble, but the chain will start wearing very quickly because it will now be ridding across the metal portion of the tensioner. This is what happened to mine, except without a fried engine. Granted it was one of the old tensioners, but the same thing could still happen with the new ones.
quote]

That's the thing. I wouldn't mind if Jaguar said at this many miles or years put new tensioners in. But nowhere do they mention this service. It's all up to the owners. And most people don't know about it.

 

Ok. Just to let you guys know the car is sitting at my shop about 30 min away and I do not have a easy way of getting there since it is kinda in the middle of no where so it will be some time until I am able to obtain that information.

 

While laying in bed, I also thought of a potential solution to this.

How hard is it to recondition a Jaguar engine using metal work?

I ask because I have a friend who has rebuilt and remachined countless Mustang V8s (he's a mustang guy) and his father owns a heavy duty metal machine shop.

Could I possibly use this to my advantage and would he be able to recondition my engine?

 

chinny:
Two professional Jaguar mechanics (which I AM NOT) have given you analysis, BUT I have to question the complete story so far as I understand it. First, the MY 02 did have metal tensioners. As posted here, they do have plastic slipper plates, but mine were less that 1/4 worn when I replaced them at 130,000 miles or so. Second, for a piece of the tensioner to land in the front rod bearing it had to pass thru the oil pickup screen AND the oil filter. So, while I have no way to question a rod bearing failure as you have been told, I do question the annalysis, at least as it has been reported so far. None of that may matter as to what you do next, but it would be interesting to know what happened. I hope you keep us posted.

 

I agree. I have never heard this happen to a jag V8. The mechanic knows better than I do I i also would like to know how it exactly happened.

 

Don't worry Sparken. I'm a heavy car enthusiast and would hate to see this happen to anyone else.

Would there be play in the rod where it meets the crank? I'm curious. Is there any long shot that a damaged timing chain could make noises similar to a rod knock? Or are the two obviously seperable.

 

chinny:
You are sorta thinking like me. I advise you get professional help. Immediately! heh, heh.

seriously, you might uncle Vinnie (you're from NJ, right?) toi help you listen. I might pull off the cross member and the pan and the lower engine stiffner (I forget its official name) and just see.

 

Sorry, i didnt comprehend any of that last post lol.

But I really want to have someone take a part that motor and tell me exactly what happened. It's going to need taking apart if there are metal shavings in the oil pan, even if it is just a damaged timing chain.

 

Is there any way we can get any Certified Techs to chime in please? I've received feedback by experienced forum members but nobody donning the "Tech Certified" pic next to their name.

 

A lot of this has seemed a little strange to me also.

Have you pulled the valve covers, verified that you have plastic tensioners, aligned the crank shaft and looked at the cam alignment flats?

Seems a little strange that a shop would pull a rod bearing cap and verify that there had been damage.

Most would stand off a few feet and say 'you need a new engine'

Please excuse the sarcasm.

 

The following is subject to contradiction from the techs hanging around here.

When you spin a con rod bearing three things can get damaged depending on the situation.

1. crankshaft con rod journal
2. con rod bearing
3. con rod big end (if it got through the bearing)

So,

1. the crankshaft journal can be built up and turned. you cannot just turn it undersize because undersize bearings are not available, so it has to be remachined to stock spec.

2. see #1, it will have to be matched according to color code. it might be easier to select a bearing, and match the operation in step #1 to the resulting requirement

3. obtain a new con rod, or sleeve the old one after a cleanup bore.

All of the above are standard operations that a good racing machine shop should know how to do. At one time, *any* automotive machine shop could have done it. Those days may be gone.

It will require extraction of the relevant pieces. I do not know if it can be done without extracting the engine on your car. On some cars it is possible. On most cars it is possible if the engine is lifted to gain sufficient clearance. But, you still have to disassemble the front face of the engine.

The in place repair only works if the con rod is undamaged and you can leave it in the engine.

edit: BEFORE you commit, see the post above from "test point". Pull the pan, undo the big end, and actually eyeball the damage. Rumour has it that dropping the pan for a look see is not too difficult. If there is nothing more than normal wear, start looking elsewhere.

 

Yes, but you have to have a look at the actual crank journal surface and the con rod. A telephone report is no good. You have to actually eyeball it.

 

I love how you end your post.....I do the same often on fb or other forums,..."voicing" my thoughts on issues what-have-ya.....hoping someone somewhere will find a bit of truth in what I have "spoken".....and I too...will shut up now......

 

I'll add that you can actually get oversize bearings, and the measuring tool.
http://www.thejaguarshop.com/Jaguar/...wards/c%7C.htm

So if the crank journal(s) have light surface scars, it can be saved.

To replace the mains and big ends is an engine out job then it's done right. You'll need a manual on engine rebuild, p.m. me your email addy. Critical the builder follows torques.

 

He can probably go well beyond surface scars since it sounds like his friend has access to a good machine shop behind him. Mind you, that will require crankshaft straightening and balancing due to the processes involved.

And it is still not confirmed reliably that the crank even needs any work. Reliable = the owners own eyeballs.

Gotta love that link: "Precision clearance measuring system for shell bearings" = plastigauge.