Hi Thomas,
Payen makes some great gaskets, IMO, I believe they'er supposed to be retorqued after the first 500 mile.

 

Thorsen
I am more curious about the loose flywheel you previously mentioned. FWIW, I am not convinced that a small amount of coolant in the oil would do this to the bearings. Additionally, are the oil passageways to the head nearby the leak spot?
Secondly, is it possible your remote filter is somehow restricting oil flow? That bearing damage looks more like oil starvation to me (no need to ask why I recognise it).

 

Have to agree that this would seem like a lot of damage for a relatively small mileage with low coolant concentration in the oil (say half a liter in 12-13 liters of oil?)

Could this be the result of prior damage to the engine? Where's you oil pressure gauge connected?

 

Yes, the wobbly flywheel. My dad witnessed it too so I know I was not hallucinating. When I removed the transmission, all 3 flywheel to torque converter bolts were still tight. I had loc-tited them upon final assembly and when I went to remove them this week I had to block the flywheel - they were still very much tight.

After I removed the transmission, I pulled the spark plugs and turned the engine over using the starter. There was no wobble.

Last night when the engine was on the hoist I used a dial indicator to check the flywheel for lateral and axial runout. It was not warped.

Finally, every single one of the bolts holding the flywheel to the crankshaft was tight. I had loc-tited them during final assembly and my impact gun had to work to get all of them off. Every single bolt was still tight.

I honestly do not know what caused the wobble.

 

On the brass tee coming off the top of the oil filter head, the sensor on the right is for the oil pressure gauge. The sensor on the left is a 10 psi low pressure switch.

I was using 20w-50 Castrol Classic and the oil pressure was 40 psi during cruise. When I stopped because I heard a knocking noise it was idling with about 10 psi.
Also, this summer I only rebuilt the head. I did drop the oil pan and pulled one main bearing cap and one con-rod cap to check the condition. They were still newish - they had probably been replaced as part of the rebuild in the 1980's.

 

Thorsen
I think it is quite possible to have pressure at that fitting but insufficient actual pressure at the bearings, if there are flow restrictions of some sort in the engine. It might be worth carefully checking that and examining all oil-paths including the crank passageways when the block is out of the car.

 

I think I found the smoking gun for the knocking noise. The #4 connecting rod bearing had spun - you can see the heat marks on the bearing cap and the tangs on the bearing shell were missing. It also looks like the bearing shell had moved towards one side of the block as the edge of the bearing shell almost looked like a thrust bearing - you can just make it out on the left side of the shell in the picture below. I suspect some of this bearing is what I found when I filtered the oil earlier this week.



None of the other bearings showed signs of having spun. I'm happy to at least figure out why it was knocking.

 

Thorsen, maybe the thrust bearing had given up, and that allowed the crank to oscilate, accounting for the wobble as well as the bearing starting to act like one?
Which might still be downstream of an oil supply problem?

 

That does indeed look Very suspicious!
I've never seen a Thrust rod bearing before. Must be one of them new-fangled Better Ideas I keep hearing about.

 

I finished tearing down the engine today and there are plenty of gory pictures to share. First up are the thrust washers and they appeared to be in good shape with no noticeable wear marks or scoring.



I also took some close up pictures of the #4 con rod bearing. My guess is when the bearing spun it started squeezing the bearing out the side. But I honestly don't know.


The other bearing shell for #4. The locating tangs were broken off which either allowed it to spin, or they broke when there was an oil pressure issue.
Either one, the crankshaft took some damage too; the #4 journal looks awful.


Here's a pretty ugly picture. #6 piston (nearest the front of the engine) had the most severe case of piston scuffing I have ever seen. I found it interesting the scuffing is not where the piston rotates on the gudgeon pin; it's on the "side" of the piston. These scratches easily catch a finger nail.


Another view.


It's hard to take a picture of a shiny cylinder bore, but there were no scratches that would catch my fingernail.


For comparison, #2 piston.


At this point given that the engine needs new pistons and full machine shop work, I have decided it is not economically feasible to restore this engine. Back this summer I loved the idea that it was the engine the car left the factory with, but at this point I have to call it what it is. I'm going to put a classified ad in to see if anyone wants the block and crank but I'm guessing it's going to get scrapped.

From here forward, I have 4 ideas in mind.
1. Replace with another XK engine. There are a few floating around but most of them have unknown histories. I do worry I am setting myself up for failure again.
2. My friend @Greg in France suggested an American V8. I like the idea but I also would like to keep things British under the hood. This afternoon I went and looked at a Rover V8 for sale near me.
3. In the spirit of keeping things Jaguar, but also being able to cruise at 75mph, I am considering buying an entire late 80's to early 90's XJ6 and poaching the engine/transmission/ECU.
4. Finally, in a nod to the tight engine compartment I am dealing with, this morning I went and looked at a 4 cylinder 2.3L ecoboost motor from a 2019 Ford Mustang. 320hp/350 ft/lb of torque in a package that is 2' wide by 2' long. The aftermarket support for this engine is robust but I'll be forced into a 6 speed manual when I wanted to stay with an automatic to match the spirit of the car.

 

Hi Thomas,
Why will you be forced into a 6 speed manual, is the auto trans too large for the tunnel?

 

Dear Lord, Thorsen, that piston is extraordinary.
I fully applaud your decision not to bother any more with that or any other XK engine. The Rover V8 is nice, goes with an auto no bother; but you need at least the 3.9 version to give you decent power.
If, as Bob S says, the ecoboost will take an auto, then why not? Even though I still say do the Yank V8 and have no future worries!
But what actually happened I wonder?

 

Hi Thomas,
How is the crank oil passages to the #4 rod? Are the passages blocked, clear or loose crap in there?
Any idea why the coolant leaked down the side of the block?
Any idea why #1 & #6 had low compression?

Then there is that rebuilt 1966 S-type 3.8L engine with papers that has been sitting for several years for $2k plus shipping. You could get it, freshen it up and be set for very little $$.

P.S. I believe the AJ6/AJ16 Jaguar engine is a little bit longer than the XK6.

P.S.S. Here is another option: I know nothing about these people.
https://www.facebook.com/marketplace...d-931933aaa3d3

 

The auto trans actually looks smaller than the 700R4 most recently in there; it's more about the ECU and the security system. The tuners I have found are only able to remove the security system from manual transmission ECU's; they won't touch the auto transmission ECU's. I'm planning on doing a deep dive tomorrow; I really like the gears 8, 9, and 10 are all overdrives.


I'm seriously considering de-greasing it and using it as a paper weight - it's pretty incredible.


I'll take a look at the oil passages int he crank for #4 tomorrow. I also got an oil filter cutter today - I want to see what secrets are in there.
Coolant leaks can be anything from a warped head or block to a faulty head gasket, but I'm putting my money on the fact that I didn't replace the head studs. My rule is to replace head studs with ARP - I learned that lesson with my MGB 30 years ago.
I didn't look too close at pistons 1 and 6 but I'm guessing the rings weren't sealing like they should.

 

But where's the fun and satisfaction in that, Bob?!

 

I saw a piston like that in college once (one of a set of 6), the Ditzy Br**d had run low on oil until the OIL light burned out (pre LED warning lights) and then, as there was no warning light, she ran it till it seized.
Then had the Nerve to tell us, "It only made a funny little noise and I turned it off right away."
(';')

 

The oil passage way in all the crank journals were clean with no obstructions. I could easily see from one side to the other. For #4 I ran a piece of weedeater line through the hole just to make sure and it was clear.

I pulled the oil filter and this little giblet was sitting right on top of the filter.



I let the filter sit in the oil pan and there was a nice trail of glitter coming out of it. This was a Wix 51515XP filter, not the stock Jaguar filter.


The inside of the filter can. That's exactly what it looks like - glitter and pieces of metal.


The final item on the list was disassembly of the oil pump. It was in surprisingly good condition given what was in the oil. If I hadn't known what it had been through I would have been tempted to re-use it.

 

So do you think the actual filter was full of bits, and the lump blocked the flow, or where else did that huge lump of crud come from?

 

I think that lump came through the oil pump but did not actually make it into the filter. It was sitting on top of the filter as if it was too big to pass into the filter itself.

 

I reckon that lump of goo was sitting IN the oi gallery, just waiting for some fresh oil to pick it up and move it. The 1st pace itwould go is the oil filter, so that makes sense.

In my mis-spent youth, Apprentice Engine Reconditioning Machinist was my "title".

Scrubbing the oil galleries of engines (block and heads fully dismantled), was fun, NOT. We used a rifle bore brush, and Kerosene, and went to it, NOT easy. Then the feeder drilling TO the main bearings were usually CAREFULLY drilled clean.
The cranks went in a hot pickle bath for 24 hours, then washed and rewashed until ALL the galleries paths were spotless.The block got the same treatment.
The amount of shiiit we got out was amazing, and since it was part of the process, thought little of it.
That goo restricted oil FLOW, and the #4 failed. Block and crank now toast, unless these old school engine shops still exist, but $ today are probably stupid amounts.

Replacement engine, yes, and I will think some on it, as its been over 50 years since my MK 7, and S Type 3.4, Back later.