1985 chevy 5.0 i/o overheating at high speed

[rbernierluc]

At high speed temperature gage goes to red<br />slow down to half speed and temperature goes to normal. idle is also normal<br /> This raw water cooled Merc.

 

[Reel Poor]

Re: 1985 chevy 5.0 i/o overheating at high speed

Is this a raw water cooling or closed cooling system. Merc, Volvo, or OMC?<br /><br />Most likely,,,water pump impeller failure, t-stat failure, or restriction in cooling system

 

[Haut Medoc]

Re: 1985 chevy 5.0 i/o overheating at high speed

Welcome to iboats I'm not a Volvo guy, but.....I would suspect that the raw water impeller would be the first thing that I looked at/replaced.......JK

 

[Don S]

Re: 1985 chevy 5.0 i/o overheating at high speed

The raw water impeller is the first thing you look at on ANY overheat problem on any make.<br />Usually they are expected to last forever, but in reallity should be replaced every couple of years.