mpnichols Posted July 18, 2009 Share Posted July 18, 2009 Need help! I have air pushing back into the radiator. No water in oil. Disconnected compressor still over presure within a minute have to leave radiator cap loose to keep from blowing up expansion tank. Pulled heads no cracks. Head gaskets looks fine. Exhaust valves and the top of cylinders 7 & 8 have alot of build up on them. All cylinder sleeves look great. Is there anyone out there that has any idea what else could be causing this. Quote Link to comment Share on other sites More sharing options...
fjh Posted July 18, 2009 Share Posted July 18, 2009 Need help! I have air pushing back into the radiator. No water in oil. Disconnected compressor still over presure within a minute have to leave radiator cap loose to keep from blowing up expansion tank. Pulled heads no cracks. Head gaskets looks fine. Exhaust valves and the top of cylinders 7 & 8 have alot of build up on them. All cylinder sleeves look great. Is there anyone out there that has any idea what else could be causing this.Pull the head that looked funny and inspect the first 3/4 of an inch of the liner AT the top you will likly find a crack!You need to sand away the carbon and inspect them closely!You also likly find the counter bore cracked under that liner.Usually the four oclock position. They crack just about where the top ring stops not often but it can happen. Quote Link to comment Share on other sites More sharing options...
Bollweevil Posted July 19, 2009 Share Posted July 19, 2009 Does the engine have a #4 vent hose from the top radiator tank to the thermostat housing, or water manifold? I have seen a plugged hose cause similar problems on other engines. Quote Link to comment Share on other sites More sharing options...
mpnichols Posted July 19, 2009 Author Share Posted July 19, 2009 The sleeves looks great super clean. There is not any carbon build up on them. As for the counter bore do you have to pull the liner to inspect that? Quote Link to comment Share on other sites More sharing options...
fjh Posted July 20, 2009 Share Posted July 20, 2009 The sleeves looks great super clean. There is not any carbon build up on them. As for the counter bore do you have to pull the liner to inspect that?Yes .I have never seen liners with out carbon on the top !They have to be as clean as the rest of the liner to see the crack!Counter bore cracks also show up as a leak on the fire ring on the head gasket you said the gasket looks good.This is an rw your working on not a MH the Cab over has an air operated heater valve also if you have a shuter stat disconect that to be sure thats not the problem Quote Link to comment Share on other sites More sharing options...
skip Posted September 24, 2009 Share Posted September 24, 2009 Yes .I have never seen liners with out carbon on the top !They have to be as clean as the rest of the liner to see the crack!Counter bore cracks also show up as a leak on the fire ring on the head gasket you said the gasket looks good.This is an rw your working on not a MH the Cab over has an air operated heater valve also if you have a shuter stat disconect that to be sure thats not the problemHow old is the engine? Ive seen an E9 liner rotted out from the outside-in from electrolisys but in that case there was a pinhole in the liner, and it eventually locked the engine up. After he haed rebuilt it we checked the voltage in the top radiator tank and it was nearly 4.5. So a good earth strap was required. That started the same though, it was pressurising the cooling system. Quote Link to comment Share on other sites More sharing options...
mpnichols Posted September 24, 2009 Author Share Posted September 24, 2009 How old is the engine? Ive seen an E9 liner rotted out from the outside-in from electrolisys but in that case there was a pinhole in the liner, and it eventually locked the engine up. After he haed rebuilt it we checked the voltage in the top radiator tank and it was nearly 4.5. So a good earth strap was required. That started the same though, it was pressurising the cooling system.We did a Both head gaskets on the Left side with new Fire rings. #4 fire ring burned through. Problem solved! Quote Link to comment Share on other sites More sharing options...
fjh Posted September 24, 2009 Share Posted September 24, 2009 We did a Both head gaskets on the Left side with new Fire rings. #4 fire ring burned through. Problem solved!Thanx for posting your fix! 1 Quote Link to comment Share on other sites More sharing options...
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