95 6.5 dually remote PMD Blown head gasket or cracked cylinder?

[DaddyB3089]

I have a 95 6.5 that I have been fighting for awhile. Started out as loosing coolant that turned into water pump replacement. Changed fuel filter and the oil while in there doing the water pump. Still have coolant lose and now also have a very bad skip. Thought overheating may have blown PMD, so replaced it and relocated to front bumper. Still have skip and seems to get worse if radiator cap is under pressure, which it gets very quickly. If I release the pressure the skip seems to get better but does not go away. If rad. cap is closed the top hose gets rock hard. Does this sound like blown gasket or most probably cracked cylinder?

[JohnC]

Most likely a head gasket. A cracked block is less likely to pressurize the cooling system and more likely to put water in the crankcase.

[suburbanK-2500HD]

Would agree with John, sympthoms is like head gasket.
i would not drive to much with it if you are getting coolant in the cylinders.
To test, remove glow plugs, and crank it..

take care.

[Kennedy]

Pull the engine and get it on a stand. Disassemble and inspect. Could be head, head gasket, or could be block deck.

Most likely head or head gasket, but at least you'll have it accessible for cleaning, inspection, and assembly.

[Robyn]

I agree with JK 100%

Most likely cylinders one or two. These two have coolant laying right next to the gasket fire ring and electrolysis causes the fire ring to errode the deck and finally the gasket blows.

Examine the deck real well. If there is any amount of errosion of the deck where the fire ring sits, the block will need to be machined and the use of a .010" thicker gasket.

Great time to freshen the old girl up and get her ready for the next 200K

Keep us posted.


Missy