So after having the engine overheat and the sweet smell of coolant out the tail pipe I pulled the heads. DS inboard piston and head top is perfectly clean which to me indicates where the water leak was present. The head gasket showed no obvious breach area and the heads do not have an obvious crack. Since the water jackets are on the outside of the outboard pistons I cant see how the head gasket leaked past one piston into the other inboard cylinder (see image below). Anyone seen this before? Could is be a cracked cylinder sleeve? If so would it be obvious?
Help is needed and appreciated....

Ken

 

Sorry to hear.

This is a common problem. The wall between the cylinder and water jacket has likely cracked, in combination with an overheated block, causes the sleeve to slip up and down a tiny bit, enough for coolant to seep in through the top and into the crankcase. Do you have coolant in your oil, too?

It's never really obvious, even compression/leak tests can often fail to confirm the crack, unless you do a hot test. Inspect the head bolt holes, do you see an hairline cracks?

The only worthwhile fix is to have the sleeves replaced with flanged sleeves. ~$1500.

Check out this article JE Robison Service - Bosch Car Service Specialists ? the blog: The last word on Land Rover liner failures - I hope!

I recommend to speak with the guys at www.qande.com to discuss some diagnostics and repair options.

If the block is indeed cracked, there are 3 options I would consider
1. Send your block to Q&E and have it top-hatted. $1500 + valve job/ head surface $400 + rebuild engine w/ new piston rings, bearings, lifters, etc ~$500
2. Buy a new top-hatted block from Turner Engineering
3. Throw in another used motor and run it dead. It's not worth rebuilding the engine if you don't do top hat sleeves.

With all that said, it could just be a warp issue on the head or block surface, and/or gasket (however my money is on a crack). You can have your heads checked for flatness first, but they are probably warped anyway - all of them are. If you absolutely don't want to pull the block, then I'd start with taking the heads to a qualified machinist and have them checked, decked, and new gaskets.

 

Thanks!.
No water in the oil but the PO could have changed the oil, it looks brand new.
I have had the heads done already. This is not the first Disco head job I have had done. These heads were only about 3mil out but I had them shaved. Didn't have a leak test done on them.

Scary about the sleeve going up and down just a bit causing this issue. I can find a bottom half easy for $500 around here (including the dicsoII). Tempted to just throw the heads on an see what happens but that could be throwing $350 away plus my time.

 

Hold up. Your heads were 3mm or .03?

 

0.003".
.03 would be 30mils. a mil is one thousandths of an inch.

 

Just a note here.
The offending cylinder's sleeve is perfectly flush with the block, no discernible "lip" or mis-alignment between the steel sleeve lip and the aluminum block. Does this mean anything?

 

A slipped sleeve doesn't lead to coolant leak, a cracked block or bad head gasket does, I have seen blocks with slipped sleeves that sounded like hell when warmed up but didn't leak coolant at all, the sleeves were so loose that after taking heads off you could push sleeves side to side with fingers & see them move,!

 

That's correct, but the sleeve can become loose in conjunction with the cracked block - due to overheating - allowing coolant to more easily flow into the cylinder bore and travel upwards leading to a 'steam cleaned' piston head, and downwards into the crankcase resulting in a milky oil. A top hat liner will fix the issue of coolant traveling upwards into the head, and a top hat liner with an o-ring at the bottom will also prevent coolant getting to the crankcase. The fix effectively turns the sleeves into a wet liner. Q&E uses LA Sleeves, and Turner uses Darton. Both are good.

A leak down test is for testing compression of the pistons - ie how well the piston rings are seated within the bore. A block pressure test will test for cracks, but may not reveal the crack because the crack is only leaking when the block is hot (225+F).

I'm pretty sure that if you don't have coolant in the crankcase, then it could just be a head gasket issue, but odds are its a crack between the water jacket and cylinder bore

 

So even though the steam cleaned piston is an inboard one, there is still a chance it could be a blown head gasket? I have no water in my oil but I also see no indication of breach in the head gasket.

 

It's a cracked block. If the engine had been recently running you could use a rag as protection and squeeze with vice grips on the cylinder wall and watch coolant ooze out.