? to Ramsport47 - posted on eng for 86 Mariner

[ecmark]

I'm working through a over heating issue - can you review the cmmts and provide insight? - or a mechanics reference in the Ocean City MD area?

I'm finding the design of my cooling system regarding repair parts to be a challenge - example, my thermostat housing has 1 hose coming from the H/E - I'm seeing diagrams with 3 hoses into the thermostat from a "standard cooling layout" ?? tks, Ed

 

[Unknown]

anybody out there able to lend a hand on this???

 

[RamSport47]

it really depends if this is a complete closed system or partial. A partial would only send antifreeze through the engine leaving the manifolds and such with sea water. The hosing would be different in each case. We do not see many closed systems here, so I don't think I would be able to help...sorry :-(

 

[ecmark]

Morning Kenny - yes it is a partial closed cooling system in that the raw water comes in and filters thru the velvet drive first then is routed to the intake on the H/E - there are two exit hoses to the risers - the water pump goes directly to the underside of the H/E with a single hose out the top to the thermostat - I'm stymied because it doesn't make sense to me that a gasket on a riser that supposedly only has raw water in it would allow for the closed coolant to escape.....I thought that only the H/E tank had an area where coolant and water were next to one another for cooling - the thermostat failing wouldn't push coolant out the exhaust would it? any help is greatly appreciated, tks! Ed
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[dmunneke]

I have this configuration as well and seems to me the olny possibility is the exchanger.

 

[geomut]

I have a 32 Convertable with fresh water Crusaders. Two sides to the cooling system, raw water side and antifreeze side. The raw water side goes in this order... sea cock, strainer, v drive, sea water pump (Sherwood), trans oil cooler, heat exchanger (raw/sea water side) and then out to the exaust elbows where the sea water leaves the boat with the hot exaust gasses. The fresh/antifreeze side is a closed loop staring at the heat exchanger, into the thermostat housing, throught the block, out of the block at the back of the circulator (car water pump)pump and back into the heat exchanger. A problem with either side can cause you to overheat. Check to make sure you have plenty of good clean antifreeze in the heat exchanger or a worn out thermostat. After that start checking the sea water side for possibe obstructions. If you are not getting enough sea water through the boat you won't cool the antifreeze in the exchanger.

check for clean intake, clean strainer, good or new impeller in sherwood pump, no junk blocking the oil cooler including peices of a replaced impeller and lastly no blockage on the exaust elbows (the water needs to be able to get out of the boat). If you have two engines and one is cool compare the temp and volume of water coming out of both.

My risers and manifolds both have antifreeze. Only the exaust elbow is sea water.