C15 Blowing coolant but no hydrocarbons

You have that much air coming out, it is most likely a head gasket. Although you could pop the unloader out of the compressor and run it for a minute just to rule that out.

Blown head gasket has a distinct smell in the cooling system. Take a sniff in the reservoir.

 

It is not air in system. If it was it would get hot. Something is pressurizing system, You ruled out air compressor, so most likely it is head. Pressure test cooling system. Do not rely on the block tester kit. I have seen those test good and the head was bad and seen them test bad and there was no problem.

 

That looks like someone trying to fix an oil leak. Has nothing to do with your coolant system. Look, you have a headgasket blown or a cracked head or a cracked liner flange if you have already isolated the air comp. And rad cap.

 

Just trying to help get the red diesel test fluid there is a big difference. The red fluid turns yellow. Have seen that blue fluid and used it never had it show anything on a diesel. Do has you want but the red does works with diesel the hydrocarbons from gas engines are totally different then a diesel.

 

I had this problem for about two years on a 2000 international with a 6NZ. I did all the test, swap the caps, still did it. So, one day the water pump started to leak at the weep hole. I change the water pump, and haven't had to add coolant since, other than leaky heater hoses.

 

I know you don't want to hear this but like someone else said, look into head gasket or head. No water pump will not pressurize system. Take a oil sample and see if you have high potassium levels, that will indicate anti freeze in oil.

 

thanks for the tip