OMC overheating at idle

[stub756]

My OMC 2.3L Cobra engine is overheating at idle. It cruises around fine, when cruising at 30-35 mph the temp is fine, its usually around 170. Then when it is brought back down to idle the temp really jumps up. It gets to be around 200. If it is brought back up to speed the temp will drop back down again. What is causing this fluctuation in temperature? Thanks

 

[stub756]

Re: OMC overheating at idle

Forgot to mention, the boat has a new impellar, thermostat, and flapper

 

[akriverrat]

Re: OMC overheating at idle

http://www.marinemechanic.com/site/page85.html

 

[stub756]

Re: OMC overheating at idle

Looked at the boat again and found hard plastic pieces in prop and a few soft rubber pieces. Is there anything like this in the water pump?

 

[sea wolf]

Re: OMC overheating at idle

it's what's left of the impeller that u changed. u have a blockage. get all of the pieces out.

 

[stub756]

Re: OMC overheating at idle

I didnt change it I bought it from a shop and i believe the shop changed it an supposedly got all the pieces out. My question is how did the pieces got through the thermostat housng the inlet is only about an 1/2 inch in damiter and there pieces where larger then the opening.... Two were white colored and the other two were black rubber material. Is it possible its something from the water pump?

 

[sea wolf]

Re: OMC overheating at idle

the white pieces are part of the impeller. they obviously didn't get it all.

 

[stub756]

Re: OMC overheating at idle

thanks sea wolf... how do we flush the outdrive of these peices if there are more? Also is the flapper a rubber piece?

 

[sea wolf]

Re: OMC overheating at idle

if u mean the impeller vanes yes they are rubber. hopefully u & the mechanic have got em all. that mechanic screwed up. didn't he run it before u picked up your boat?

 

[stub756]

Re: OMC overheating at idle

Sea wolf yes the boat was run.... My theory is the old impeller pieces werent blocking flow till now. They said they replaced a piece called the flapper and thats what the other flismy rubber pieces were. At speed the boat runs cool just at idle it ran hot.