There are no water passages in the Intake near #5, so I don't think that is it. I would suspect either a cracked head, or a cracked head bolt socket due to the #5 head bolt loose. I would see if it can be torqued to spec, if it cannot you have a cracked bolt hole. After that, if it was mine I would position one of my other Disco's nose to nose and connect the cooling systems with block off plates in place of the heads with fittings in the block off plates. A crack in the block might not be visible unless the whole thing is hot. That said, if the block was cracked you would probably have water in the oil, so that seems to indicate a cracked head is more likely. A competent machine shop should be able to pressure test the heads.

 

Right, so my thought is, if it was leaking around the sleeve, the coolant and exhaust gases would mix which seems to be happening.... HOWEVER, there's no explanation for why we see water in the oil. For this reason only, I tend to think maybe it's not leaking around the sleeve.

The head bolt socket is very suspicious indeed however, once again, if its water coming through the socket, how is it getting into the oil? Puzzling again.

As you stated, there is no water passage near #5, so if I'm not looking to the sleeve, I can only look to the head. I'll have it pressure tested so we can rule that out. I think I can use Vaseline to hydro-lock the bolt socket and prove it holds pressure and therefor isn't the culprit, if not I think I can pressurize it with a syringe or similar.

 

FWIW when I pulled my heads off last year the center top bolt RH side was quite a bit looser than any other, which were as tight as you’d expect.

when I brought my heads in to the shop, a reputable one, the guy told me that means it overheated. To my knowledge it hadn’t, but guy knows his stuff so I lean towards him being right. I saw bubbles out of cylinder 4/6 no coolant symptoms at all, just misfires.

so possibly loose bolt is symptom of overheating. Again, FWIW.

 

It's worth something. It's not uncommon for this to occur but hand tight seems a bit odd. He might be correct, either that or hydro-locked combustion chamber stretched it, both are bad. It's not a lack of gasket material since mine is only a corroded inside not blown out.

Appreciate the input. Info is the key to these.

After work today, I was able to cut a few 2x4 scrap wood chunks and drill em out for the head bolts to create a block for the jacket, I used a tiny hair spray bottle with a hose clamp to block the water pump hose right out of the pump. I'll use the other hole in the top of the head to force a rubber air nozzle against and pressurize the block looking for leaks. I won't have many great options to pre-heat the head, a couple heat guns might have to do it. Not safe in the vehicle to do much more. I suspect I can hold 80+ psi in this fashion pretty easily since the hold is a half inch square area at most, meaning 40lbs of hand pressure would do the trick. Perhaps I can make that sleeve leak and spot my problem.

-Greg

 

That’s ingenuity. Let us know how it works.

 

The water passage that leaks into the middle cylinders is in the valley/inside the block only and doesn't go up into the heads. The only passages that go to the heads are on the end cylinders, which is why when you have water going into 5 or any of the other 4 inner bores then the problem is a cracked block in the interior side.

 

This is what I noted as well, however, I then wondered if inside intake manifold a crack could distribute water to the middle cylinders potentially. If it's possible, I'd think perhaps it's worth testing the intake manifold as it clearly has water circulating through it normally. I haven't got to track the water path however. Do you know if this is a possibility?

 

Test everything that you can, if you can, I would think. But it seems to block is cracked. You seem to know what you are doing, and you can get a good bare block fairy cheap and use your old good parts to rebuild, or whatever is still good anyway. I'd recommend upgrading cam it makes a noticeable difference in performance.

 

The story gets stranger:

So, I just rigged up my block tester. I used two short 2x4 scraps and drilled hold bolt holes. I used a rubber glove under them as gasket improvement against the block. This leaves the main hose connection at the pump, which I jammed with a hairspray bottle and hose-clamped. The two tiny holes in the block for the head work perfect for one finger to cover and the other to use a rubber spray nozzle tip for the air compressor. I put 30psi to the block with soap all over. Nothing but the water pump gasket leaks and it just weeps slowly at over 18psi. The coolant system would typically see 1.1bar (14.7atmospheric x 1.1) so it'd barely see 16psi ever in this system before the cap blows. Granted I've no way to heat the block but I don't think I want to put more pressure to what might be a good block.

Now Guess What happens:

Well, the other head was still on and sealed! Still with the push rods gone, the valves should all be shut, there should be no way into or out of the combustion chamber with spark plugs still in.

So I pulled the head, the gasket looks perfect. So the only thing I can think is that the HEADS ARE CRACKED! Both ends inside where the water jacket must share a metal wall with the intake port. Furthermore, if it's on both ends of even the good side of the motor, could it be on one or both ends of the other cylinder? So I'll have both heads pressure tested. Now still, the question of why was cylinder #5 steam cleaned and no others were? I could see how perhaps some water would make it into the oil if it's in the combustion chamber perhaps but why aren't all the outside cylinders my issue then? Is it possible the water made it into #5 and for some strange reason pressure washed it but wasn't hot enough to pressure wash the other cylinders? I'm still missing part of the puzzle here no doubt but perhaps my block is ok and the heads are my issue.

Very strange..........
Oh and it seems this fella is experiencing EXACTLY what I am, worst part is I trolled his posts and he ends up doing the top hat liners and they still leak!!! Same issue remains after he spends a ton of money on the motor and then he just disappears and I expect for a bad reason. Granted he didn't pressure test his block and I have, though I'm not sure of my test being fool proof. He does test his heads twice and they pass. If mine fail, the two stories are different. Let's hope.
https://www.landroversonly.com/forum...38/index2.html

-Greg

 

Hmmm, who woulda thunk it?