Volvo Penta 5.7 GS with closed cooling system

[McCluskie]

Hi All,

I'm winterizing my 1999 Doral 216cc with VP 5.7GS (SX drive). I installed a closed cooling system in 2004 when i started running the boat in the ocean. Usually, I get a marine shop to winterize but doing myself this year.

Planning to flush the raw water intake with antifreeze using muffs. Most advice says "run the engine for 5 min first to open the thermostat". My question is: With the closed cooling system, can I just start flushing anti freeze through the muffs immediately (without the 5 min warmup), since the thermo is on the closed side of the system?

Thanks in advance,
Mike

 

[alldodge]

No need to run motor for the thermostat to open with closed cool. Drain the heat exchanger and anything else on the raw water side, then use AF

Now for changing the oil, might want to run it a bit to suck the oil out

 

[Lou C]

On these usually the system is a half system where only the engine is on the closed system and the manifolds and elbows are all raw water cooled. So you’d have to drain the heat exchanger, manifolds, & raw water intake hose. There is a water drain on the pivot housing (the part that the drive is bolted to) on the port side that also helps to drain this hose and the P/S cooler on the rear of the engine. If that plug doesn’t drain (poke it with a pick) then hold the raw water intake hose up in the bilge after draining it and fill with -100 marine AF till it runs out the drive water intakes; that will push out any residual water.
Now if you wanted to use the tank to winterize you can with this system because the raw water pump will suck in the AF and it will then enter the H/E and exit the exhaust. I would use a live well pump to pressurize the flow because with engine mounted impellers sometimes it is hard to get the impeller to Prime with just a gravity flow.
So run it up to temp on the water hose to change the oil & filter then run it again to check for leaks and to fog it if it’s a carbed engine. Then you have to decide if you just want to drain manually or suck in the AF.

 

[McCluskie]

No need to run motor for the thermostat to open with closed cool. Drain the heat exchanger and anything else on the raw water side, then use AF

Now for changing the oil, might want to run it a bit to suck the oil out

cheers! thank you.

 

[McCluskie]

On these usually the system is a half system where only the engine is on the closed system and the manifolds and elbows are all raw water cooled. So you’d have to drain the heat exchanger, manifolds, & raw water intake hose. There is a water drain on the pivot housing (the part that the drive is bolted to) on the port side that also helps to drain this hose and the P/S cooler on the rear of the engine. If that plug doesn’t drain (poke it with a pick) then hold the raw water intake hose up in the bilge after draining it and fill with -100 marine AF till it runs out the drive water intakes; that will push out any residual water.
Now if you wanted to use the tank to winterize you can with this system because the raw water pump will suck in the AF and it will then enter the H/E and exit the exhaust. I would use a live well pump to pressurize the flow because with engine mounted impellers sometimes it is hard to get the impeller to Prime with just a gravity flow.
So run it up to temp on the water hose to change the oil & filter then run it again to check for leaks and to fog it if it’s a carbed engine. Then you have to decide if you just want to drain manually or suck in the AF.

cheers! thank you