Reply
Highlighted
Trusted Contributor
Trusted Contributor

Re: G379TA Air in Cooling System

The only other place that I can think of is a crack in the exhaust manifold.  The jacket water flows through the exhaust manifold and it would have less pressure that a cracked cylinder head or a liner counterbore crack.  And that would also account for the sudden pressurization of the cooling system.  And exhaust might show up as combustion if it came from the exhaust manifold.

 

Best Regards,

Al Hunt

New member

Re: G379TA Air in Cooling System

The problem occured all of a sudden on a high hour engine. Initially we assumed a cracked head, we did find a cracked head, but replacing heads did not solve problem. Then tested radiator for combustion gasses and found none. I had heard that our air to air exchanger is rare. The problem doesn't occur until engine gets up to temperature, installing a higher pressure radiator cap kept the coolant from overflowing for a slightly longer period of time.
Trusted Contributor
Trusted Contributor

Re: G379TA Air in Cooling System

The G379TA did not have the option for an air-to-air aftercooler.  If your engine does have an ataac, I don't know of a connection between the engine jacket water and the ataac.  It could be that a connection has been made in error in the external piping.  Did this problem just start after a repair or has it been slowly occurring?

Best Regards,

Al Hunt

New member

G379TA Air in Cooling System

Air is pushing coolant out of expansion tank, but can't identify source. Replaced heads and head gaskets, compression tested all cylinders, tested expansion tank for combustion gasses, not exhaust. Tank stops overflowing when turbo air is blown down at the air to air exchanger. Where would turbo boost air come in contact with water cooling system?