planeracer
Cadet
- Joined
- Aug 5, 2011
- Messages
- 12
Hello,
I have a Volvo 350 5.7L engine on my boat. It is raw water cooled cooling system and I installed new manifolds , raisers, sea water impeller and 160 F thermostat on it. But, last weekend I found new problem with it, all running ok up to 2000rpm . Temperature around 160 F. As soon rpm passes 2000 temperature starting to going up, I never let it go to high,
Lowered rpm, and temperature went back to normal again. It seems not enough water from sea pump to cool engine
down. I read a lot on the net about that problem, but first think what i did, I lowered outdrive into big bucket to cover sea water inlet holes. BTW, I have 275 outdrive unit. Then started the engine, waited couple min. and pulled sea water pump hose from thermostat housing to see how much water impeller pumps water out, at idle it was ok, but water had lot of air bubbles in it, looks like hose sucks an air from somewhere and actually im not sure how much water must come out from that hose. I pushed rpm up to 2000 and amount of water changed a little but amount of air bubbles increased a lot. Outdrive is not completely in the water , only inlet holes. Now, Is airleak causes that problem? or I still have to go forward and check for impeller condition, or I have a bad thermostat? Please let me know what you think.
Thank you
I have a Volvo 350 5.7L engine on my boat. It is raw water cooled cooling system and I installed new manifolds , raisers, sea water impeller and 160 F thermostat on it. But, last weekend I found new problem with it, all running ok up to 2000rpm . Temperature around 160 F. As soon rpm passes 2000 temperature starting to going up, I never let it go to high,
Lowered rpm, and temperature went back to normal again. It seems not enough water from sea pump to cool engine
down. I read a lot on the net about that problem, but first think what i did, I lowered outdrive into big bucket to cover sea water inlet holes. BTW, I have 275 outdrive unit. Then started the engine, waited couple min. and pulled sea water pump hose from thermostat housing to see how much water impeller pumps water out, at idle it was ok, but water had lot of air bubbles in it, looks like hose sucks an air from somewhere and actually im not sure how much water must come out from that hose. I pushed rpm up to 2000 and amount of water changed a little but amount of air bubbles increased a lot. Outdrive is not completely in the water , only inlet holes. Now, Is airleak causes that problem? or I still have to go forward and check for impeller condition, or I have a bad thermostat? Please let me know what you think.
Thank you