Draining Coolant from my QSB 5.9 engine

[Peter Van Rossem]

Thanks for letting me ask this question…I have a Cummins QSB 5.9 and I am in the process of winterizing this engine. I emptied the raw water from the main cooler on the port side and emptied the exhaust silencer before adding the Antifreeze. Started up the engine and sucked the Antifreeze in until I saw the red coming out the silencer so I’m sure this is done properly.

Because this is a new boat and I am not a pro winterizer, I measured the coolant freeze level ( this is for engine, not raw water side) and found the Antifreeze to read -18C…after winterizing the engine. Where I live, it can get to -28C. So now I need to drain the engine and refill with -40 (prefered)
My question is, when I pull the plug on the starboard heat exchanger, will it empty the entire block? Do I have to worry about the water pump holding some -18 antifreeze as well as the thermostat holding -18antifreeze as well. I really don’t want to start the engine again…A, because I am on the hard and B, to get the thermostat to open to circulate the new -40 Antifreeze can’t be done without hooking up a water hose to the raw water side. Thanks for letting me post. PETER

Topic

[Rob Schepis]

Yup, coolant check/change should have been done before decommissioning the boat. Only way I see it at this point is to remove the tstat from the housing and flush the higher protection coolant through from top down.

[Author]

Replies