I have engine oil ( not transmission oil) in my radiator. The cooling system always blows coolant ot the overflow bottle and makes a wooshing noise through the heater core. This has started about 1,000 miles since I replaced the head and head gasket. I just removed the oil cooler tonight and pressure checked it. It held air. I then sealed the engine breather and oil ports for the oil cooler and pressurized the engine trough the dip stick tube. I did not hear air comming from the engine block.

My question is do I have a bad head gasket, engine block, or am I missing something else?

For what ever its worth, the head and gasket are oem.

 

most likely culprit is the oil cooler.

 

Don't you think if the oil cooler holds air it should hold oil?

 

Any air bubbles coming out with the coolant?

 

I never saw any bubbles, which seems strange considering the problem I'm having.

 

Based on your description that the problem started after the head and gasket change, I would suspect you reused the old headbolts, and that you are now leaking oil through the headgasket. The OEM Cummins headbolts are a one time use product that depend on a predetermined stretch to set the tension, and even though there are claims that they can be reused, I have yet to see a case where reuse has proved successful.

If it were your oil cooler, you will find considerable coolant in the oil when you do an oil analysis, and a pressure test of the radiator will identify a significant leak. A headgasket may not leak until the engine is hot and under load.

 

I replaced all the head bolts. The reason the original head gasket leaked is one of the head bolts, particularly the bolt closest to the exhaust manifold over the # 5 cylinder. The original leak leaked coolant externally down the side of the block.

Assuming the current head gasket is the problem, RCW, do you think it could leak oil into the coolant? It seems likely, being that the oil pressure is substantially higher then the coolant pressure. I just hate pulling the head off for no real good reason, or to do it and have the leak re-occur. I also can't believe the block is cracked, but I'm sure I'm not the first if it is. Plus how would you know if the block is cracked being that it has cast in cylinder liners that mimic a wet sleave design. You can only see the first two cylinders through the oil cooler opening.

As you can probably tell my head is swimming about this.

Thanks in advance for everyones advice.

 

If I remember correctly there was a update on the oil cooler gaskets. I have seen the service news letter that was issued buy Komatsu. They use alot of "B" series in their equipment. PM me if you want more info.