I purchased a 2002 disco 2 with 131K miles on it. I thought it may have a bad head gasket, but wanted to get a definitive diagnosis because I have read of several people replacing the head gasket only to find a failure someplace else (I have been hoping for a timing cover gasket). I also want to rule out a slipped liner, cracked block, or bearing problem before dumping money into the vehicle. The previous owner said it had an overheating problem and parked car and then found the coolant in the oil. I ran a compression test and all cylinders were between 155 and 160 psi cold. I pulled the oil pan and pressure tested the cooling system. I found a small leak on a connection to the heater core, but the system has held 18# for an hour and I see no obvious water leaks coming down into the oil pan area. I do not want to do work that is not needed and want to rule out a slipped liner, cracked block, or bearing problems before moving forward. Does anyone have good advice on how to diagnose the problem?

 

An exhaust gas in coolant test ($60 ish for a kit that does maybe 15 tests) will point at head gasket or cracked block. HG much more common. If you pull off the heads, before buying HG gasket set, you can rent a block tester that uses block off plates and lets you pressurize block with shop air. Little bubbles alongside liner tell you what you don't want to know. You can do bearings with engine in truck, see our tech area.


HGs run $90 - $125 for a kit, my machine shop charged $250 to machine heads and do valve job and test heads. Now how long it will take depends on weather, work space, tools, skills, other duties as assigned, etc. Some members are so skilled at this they can do it in their sleep. A rule of thumb is two long weekends with machine shop inbetween. Ask a buddy over, he'll come so he is not stuck watching figure skating...

 

"I also want to rule out a slipped liner,"
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For certain, if you pull the oil pan, OR the heads, you can tell if any cylinder liner has moved up or down. In the block, easily seen when oil pan is off, at the base of each liner, you can see if any liner has moved upward, if any are are not sitting flush on the aluminum shoulder, in block, at base of each liner. They should all sit flush against the aluminum shoulder at base of each bore; if any do not, but they have a gap between the bottom of liner and the aluminum shoulder at base of each bore, they moved upward, or were not flush when it was originally assembled by Rover, which happened, by the way; Rover didn't notice that, or chose to ignore it. With heads off, you can easily see if any liner has moved downward---top surface of each liner should be even with top of block bore. Only other way to determine if any liner has moved, is just guess work.
With oil pan off, you can simply look at connecting rod bearing inserts, and main bearing inserts, to determine their condition. If they look pretty good, not gouged up, no copper metal color showing on friction surfaces, you can test them for wear, by going to auto parts store and buying some inexpensive plastigauge in ranges around .001 to .003. Plastigague looks a lot like thin dia. spaghetti. To use, cut off a short piece of plasticgauge, clean all oil, etc. from rod or main bearing insert, place the p gauge in center of area, running it from side to side, put bearing bolts back on, tighten to specifications, take it back off, and compare how squashed it is, with guage printed on side paper p gauge came in, and "presto," that will tell you how much tolerance there is.

 

I'd say pull the heads to check for a slipped liner. You would probably see an imprint in the head. There are some pictures showing this on this forum somewhere. You can fix a slipped liner by pinning it, but you can't fix a crack in the block. People have had luck using ironite to seal block cracks, but that's not going to be a permanent repair.

 

Thank you to everyone for their suggestions. I will pull a couple rod bearings to check for damage. If they do not look too bad, I think I am going to reinstall the oil pan with new gasket, replace the oil, run some, watch carefully, and then test for combustion gasses in coolant. The coolant was low enough that I had to add close to a gallon to pressure test. I assume I may have to run it a little to get an accurate coolant/combustion gas test.

 

I highly reccomend you you read this article if to find out about slipped liners

JE Robison Service — the blog: The last word on Land Rover liner failures - I hope!