OMC 5.7 Overheating

[mlmorton]

I have a 1989 Seaswirl with the OMC 5.7L. When I am sitting at idle, backing in reverse or going at very slow speed, I tend to overheat. If I power up to higher speed, the temp comes down to normal. Do you have any suggestions on how to check to see if my stern drive pump is getting water up to my engine at idle? Should there be water flow if I pull the hose that feeds from the stern drive to the water pump?<br /><br />Thanks for any help you can give me ...

 

[Lou C]

Re: OMC 5.7 Overheating

If you disconnect the hose that goes from the transom housing to the thermo housing, and start it, you should get a stream of water 2-4" high. If not you need to look at the impeller (rear of upper gear housing under the plastic cover).

 

[mlmorton]

Re: OMC 5.7 Overheating

Thanks for the reply. I changed the impeller in the transom. The old one looked fine. I did get good water flow with the hose disconnected at the thermo housing. I still have the same problem. It heats up at idle and will cool down to normal if I power up an run out at higher engine revs ... sounds like I have a circulation pump problem on the engine ... thanks for any advise

 

[Bondo]

Re: OMC 5.7 Overheating

sounds like I have a circulation pump problem on the engine

I'd sooner Think you have a Blockage in the Cooling System............<br />T-Stat...<br />Manifolds....<br />Risers.........