Hi Everyone,

Hope 2025 is off to a better start for you! I was informed that I need a new engine due to the wrist pin coming lose in one of my cylinders. The symptoms were blue smoke coming out of one of the tail pipes upon start up and when the gas was hit. The plug in cylinder 4 was also significantly fouled. My thinking was, rather than buy a used engine, to either bore out the cylinders and put in oversize pistons or sleeve the one bad piston. The problem is, the machine shop by us, and my mechanic, say they cannot find the necessary components such as main bearings, rod bearings, bolts, pistons, etc. Do any of you know where one could source these parts or is this a lost cause? I find it hard to believe that you cannot rebuild one of these engines but it is looking more and more like that is the case.

Thanks!

Corey

 

Sorry, can't help you with locating parts but I have a similar story. I had a broken wrist pin in my 1997 XK8 engine 2 years ago. No engine rebuild place would touch it due to inability to find parts. After 3 months of searching I finally found a rebuilt unit 4475 km (2780 miles) away and had it shipped here and had my mechanic do the re and re. I hope it turns out better for you.

 

There's an XKR engine in Coral Springs, FL on Facebook marketplace. Says that it was rebuilt, but it does need the chains swapped over from yours. Only $779 if it's still available. Seems like that may be a way to go - remove yours, swap over the good stuff, check all the seals and stuff, install.

 

That is really bad luck.

I believe that the X100 gudgeon pin is held in with circlips and it would be extremely unusual for one of the clips to let go as they are not subjected to much lateral force. Can I ask whether you have inspected the damage for yourself as I am sceptical.

Having said that, if parts are that difficult to find, replacing the engine might be the best alternative if you can pick up a low-mileage engine plus ECUs at a reasonable price from a crashed car.

Richard

 

Wow awesome, thanks for the info. I will definitely take a look and that is not too far from me as I am in Sarasota. Appreciate the heads up!

 

Bummer, I am seeing how this is just simply the case for us now. Parts are getting harder and harder to come by unfortunately. Disappointing as these cars are so beautiful and fun to drive.

 

I have definitely not seen it myself but my local indy Jag mechanic is super honest and reliable. He said they looked in the cylinder with a scope and saw the damage. I suppose I should see it for myself just for experience, and the purchase of a new tool (the scope), but I trust him 100%. If anyone is in Sarasota or Bradenton and needs a mechanic check out Renaissance Motor Cars on Clark Road. They are Jaguar nuts like us.

Looks like we will be looking for a replacement engine but I would hate to go through the hassle to find this happen again down the road. Always thought these engines were bulletproof but I guess my luck has run out. My mechanic said he was shocked that this happened, just bad luck I guess. I actually have another 2003 XKR but it has 127k miles on it and I would not want to spend the $ to swap its engine into my other one. Hopefully, the engine that was located by AbnMike is solid and still available!

Thanks!

 

Darn, looks like that FB Marketplace engine is from 2000. Back to the drawing board! On a side note, the car actually runs great, low miles, just puffing out smoke. Anyone have any idea what it might be worth in its existing condition? I am thinking about just dumping my two fancy paperweights and starting the whole journey over with a "new to me" 2003 or 2004 XKR.

 

For a fellow XKR 4.2L owner, that is a scary problem to learn the existence of.
How many miles were on it when you started noticing the blue smoke?
Hope you get it resolved!

 

Wouldn't it fit anyway? I'm not an expert but wouldn't an XKR engine from any year swap in?

There's a 2001 in NC with an upgraded pulley ($500?)

I'm betting with a bit of scouring the internet and calling some junk yards you can find one with low miles.

 

The AJ27 and AJ34 engines are 'different animals'.

Besides the displacement difference, the engine management and manifolds are also different.

The parts can be swapped around and made to work with a mix of blocks and heads but not worth it.

 

The symptoms as described do not point to the cause as described. Are there any other symptoms? Any unexpected sound?

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Ah. thanks!

 

I don't understand what everybody is talking about when they claim the parts are unavailable.

I just did some very basic Googling and I found mains and rod bearings for this engine from multiplier suppliers. The Jag dealers still carry them, albeit you buy mains by the piece, upper and lower, and they come to about $40 for a pair. But other vendors sell King bearings, for example, that fit.

I also see piston rings available, albeit at eye-watering prices.

Also, I strongly suspect that mains/rod bearings, and other internal stuff from the Lincoln 3.9 will also work. A decent shop will have all the cross-reference material available.

Anyway, I think the shops saying these things can't be rebuilt due to lack of parts availability may just not want to do the work.

Having said that, I do suspect that this is a lot like my BMW engines - the price of parts to rebuild the engine are so high that it's often more economically feasible to simply swap engines.

BTW, I, too, would love to know how a clip failed and caused the wrist pin to walk out and gouge the cylinder.

Edit: I do see that pistons for the XKR may be a problem. N/A pistons are almost $700 each at the dealer, and it's not clear if they come in any size other than stock. I'm sure a custom piston can be ordered from one of several piston companies, but, as alluded to above, the price is quickly going to go skyward.

 

There were minor puffs of smoke at start up in the last year but they increased to the point where there is a pretty serious puff at start up now and pretty much anytime I hit the gas from a stop. The car has 68k miles on it.

 

Maybe it is not the issue. I am no expert in this department. Really no sounds that are off, I just drove the car to golf and back and opened it up on the highway a number of times and she feels very youthful and responsive. Maybe it is something else?

 

Was the diagnosis from the garage based on examination with a borescope? Was it just based on the visible symptom of smoke from the exhaust.

If the garage's diagnosis was not based on a borescope inspection or removal of the cylinder head, I stand by my suggestion at the start that the garage have made a mistake and I would certainly never trust them again. Any mechanic who diagnoses a slipped wrist/gudgeon pin without visual inspection of the cylinder bore, and even then it wound not be conclusive, is just making stuff up as they go along. The fact that you are still driving the car speaks volumes.

Richard

 

They definitely put a scope in the cylinder to reach their diagnosis. And the car, although it drives fine, puffs a lot of smoke pretty much whenever the gas is hit.

 

It's not going to be easy to diagnose a slipped wrist pin from a borescope examination as the mechanic will not be able to see the wrist pin. All that might be visible is bore scoring which could be due to a broken ring and is more likely, assuming that the oil smoke is due to a bore issue.
If it were my car, I would check the compression in the suspect cylinder compared to the other cylinders both dry and after adding a little oil to the cylinder. It might well be that a fine honing of the bore plus new rings will be sufficient to render the engine viable again. Oil consumption might be slightly raised going forward but that might well be manageable and would be much less work that a replacement engine etc.

Richard

 

Agreed. Sounds much more like a broken ring. That would be far more likely, and could cause bore scoring.
You might get lucky and find only a seized ring.
If its running well as is, I'd run some oil borne engine cleaner through it, like SeaFoam or Marvel, and see what happens in the next couple of thousand miles.