V8 5.7L 350Hp heats up at low Rpm

[easycom]

Hello I Live in Greece and My problem is that when I run the boat at high rpm temp stays at normal but if I slow down (700-1500rpm) temp rises.<br />Anybody knows what happens?<br />Thermostat,impeller,manifolds,elbows,bellows all are brand new.<br /><br />Thanks in advance.

 

[marunr]

Re: V8 5.7L 350Hp heats up at low Rpm

It sounds like the impeller isn't working. It isn't pulling any water up in to the engine, but at speed the force of the water is pushing itself up.

 

[Dunaruna]

Re: V8 5.7L 350Hp heats up at low Rpm

Hi easycom,<br /><br />Could you give more info like: year, type of outdrive, fresh or raw water cooled, why all those parts have been replaced, who did it and finally, do you have a spare room for a couple of weeks <br /><br />Seriously, a bit more background info would be good.<br /><br />Aldo

 

[Wart T]

Re: V8 5.7L 350Hp heats up at low Rpm

That's a classic impeller symptom. I don't care if it is a new impeller. You need to check it again. The complete housing may need replacement. Never assume a part is good just because it was recently replaced. Take it from an Old Bald Fat Guy that has been around the block a few times.

 

[Baldguy]

Re: V8 5.7L 350Hp heats up at low Rpm

Hey Oldbaldfatguy, <br /><br />You don't have a copywrite on that username do ya? I might need it in a few years

 

[easycom]

Re: V8 5.7L 350Hp heats up at low Rpm

Hello to all and thanks for the responce.<br /><br />Its a 1996 engine sea water cooled with A1 Drive It was Inboard converted for drive. I replaced the manifolds and Elbows because the where ready to start leaking.belows and impeller as a regular service.<br />The fact is that the engine did not have a thermostat as most of the people here in Greece remove them (That is because the sea water during summer is hot 18-25 Celcius). <br />Without the thermostat the engine runs cold no matter the Rpm or time running.<br /><br />Thanks again.

 

[easycom]

Re: V8 5.7L 350Hp heats up at low Rpm

Sorry its 250Hp

 

[Wart T]

Re: V8 5.7L 350Hp heats up at low Rpm

You can have it in a few years Baldy. I'll use Olderbalderfatterguy. Or maybe just Deadguy.