Over heating problems

[michaelxmas]

Hey guys, I need your help again. A while back I turned over the engine and it started but the fan belt did not turn? Shut it down and went on-line here and one of the guys suggested that I loosen the fan belt and check the water pump to see if it was stuck. He said sometimes the engines turns in reverse when it stops and flips the impeller. Well I checked and sure enough it had flipped so I turn it back in the right direction and was ok for a few hours of cruzing around. But I want on another long cruz yesterday and the overheat buzzer went off. I shut it down and let it cool off. Started it again and temp was fine at 175 degrees. But the right side header was very hot and the left side header was running much cooler at about 90 degrees. At 1000 RMP'S it was ok, but as I run it up to 1,800 RMP's it started to over heat again. I thinking it's the impeller, but I put a new one in this season and it's pretty darn hard to get to and I just want to see if there is anything else I should check before I climb down there to pull out the pump again to check the impeller.

[chpthril]

I'd bet the farm the impeller is toast. What engine do you have? If it's a Merc with the old plastic housing, check it real close. It may need to be replaced too.

[laserfish]

Also,if the impeller has started to come apart, the vanes can get lodged in the cooling system, partially blocking sections of it. When you change it, be sure and backflush good to ensure there is no blockage.

[SPBFAN]

What type of engine and what year boat do you have? Rather than us all speculating we can give you more help if you tell us this way we can point you in the best direction for repairs.

[AdaminMN]

I think laserfish is on the right track, especially of one side is hotter than the other.