over heating !!

[bluerunner1]

i was on the lake and from the middle of no were the temp whent up to 240 the coolant liquid drained out i dont know where to start its 1980 merc cruse 470 4 cly 170 hourse conseled system <br />i just put a new head gasket last month and every thing was smooth the past 4 weeks

 

[Haut Medoc]

Re: over heating !!

Did you change your impeller?

 

[bluerunner1]

Re: over heating !!

no i did not change it

 

[bluerunner1]

Re: over heating !!

i did not change the impeller

 

[Haut Medoc]

Re: over heating !!

Check your water flow by removing the hose that comes from transom and connects to the heat exchanger and start the engine. I assume that it is still in the water or you will have to use muffs. There should be good flow there, if not you need the replace the raw water impeller in the out-drive. Don't let it run anymore than you need to (10-20 seconds)or it will fry the ehhaust boots........J

 

[bluerunner1]

Re: over heating !!

thanks alot i will try it and maby clean the heat exchanger it might be dirty .. or blocked

 

[Haut Medoc]

Re: over heating !!

Though it would't hurt to flush the exchanger,although the sudden over-heat doesn't point there if you had trouble free operation for the past four weeks. Check that water flow & post back...J