head gasket/possible cracked head

[jdsmith46]

Good day folks. I am a newbie hear, but a seasoned Land Rover owner. I currently have a 1995 Disco I. I have had 3 Range rover classics over the past 5 years, 1994,2-1995's.
I bought this truck with a bad head gasket and here is where I start.
I have always serviced all of my land rovers and have become well versed in the engine bay(as all of us have) I took the heads off and sent them to be machined. There was one head that was .07 out of range, not too bad. All else looked good.
I out it back together and sealed up the intake gasket well as everyone has recomended.

Since the install it had what I thought was a restriction in the water flow. Other mechanics said no, just a lot of air pockets. I tried for half a day to get the air pockets, but no luck.

I replaced the thermostat and had trouble again with the air pockets. It got hot once, not in the red, where the electric fan came on during this process. I shut the engine off and let the fan run. A few moments later I went to start it and it did not want to start. I about fainted as my first thought was hydrolock!
It started on my second attempt, about 20 seconds. It ran fine, but still bubbles coming through the expansion tank. I ran it around the block and all seemed well.
A couple hours later I drove it and about 2 miles down the road a burp of pressure came form the expansion tank. Back to square one I go.
I went through the whole process of burping the system again( elevate the truck, elevated fill funnel on tank, raising the idle) It seemed to be back to normal.
Two miles down the road again it does its trick and the temp shows hot. I pull over and shut down. Its steaming pretty good. I turn the key to see the temp and it shows cool already. I start it and it runs ok. I gimp back home to dive in.
I removed all the plugs and found #3 had moisture/coolant on the plug. I realized that there is no water inlet/valley near this cylinder. Either a cracked sleeve, slipped sleeve, or cracked head.
I stripped off the head and found some issue with what was happening. First and foremost there was massive water restriction in the rear head water jacket. The gray sealant I used had smashed inward and created a serious water restiction. The head gasket looked good and the head bolts were tight. I inspected the cylinder sleeve and it looked good. I actually got in the engine bay with a maginfying glass and located no evidence of a crack.
I took the head back to my machinist and he is pressure testing it in the morining. His thoughts are with mine not a cracked block, but a cracked head between valves due to lack of coolant there.

Please read and learn from my endeavor. If you have any thoughts please post them.

[DISCO INCUBUS]

I think you found the problem yourself ( Grey sealant ). The head gasket should go on
dry . Did the machinist magnaflux the head etc ? ...

[jdsmith46]

the head gasket went on dry, the intake had the gray sealant. The pressure test was done today on the head and there was no leak found. Question to all. Should we heat up the head to see if the crack appears or am I doomed to a bad sleeve/block issue? I feel I know the answer, but hit me with your best shot!!

[pavel]

jdsmith46 - help me understand this 'grey sealant' problem please. When I beheaded our 96 Disco 4.0 2 years ago, I don't remember putting any RTV sealer on the 'valley gasket' under the intake manifold except at the very front edge and back edge where the rubber inserts are. Did you put sealer all over the surfaces (upper and lower) of this gasket? Is 'grey sealant' the same as RTV sealant?

[jdsmith46]

The grey sealant is RTV sealant. I placed it around all four corners where the coolant flows on the corners. Needless to say I will be much more cautious.
I pulled the engine yeaterday and I can now see where the no.3 cylinder has slipped down about the thickness of a fingernail.
I will be taking it apart this weekend

[pavel]

I thought the steel cylinders are cast into the aluminum block. I guess I am wrong - are the cylinders pressed into the block; how could a cylinder slip down???

[onslow]

It does occur now and again the liners are pressed in I had a 3.5 did the same thing but mine totalled the block was cheaper for me to buy another engine as they are cheap over here

[pavel]

Live and learn!