Volvo Penta 5.0 GL

[grandefermagio]

I have a twin engine Volvo Penta 5.0 GL. About a month ago the starboard engine overheated and hydrolocked. I was lucky I removed the plugs, blew out the water and changed out the impeller. Everything has been fine. So, being the concerned boat owner, I promplty changed out the impeller on the port engine. The impeller was not in to bad of shape just a few small peices missing. Well when I got on the lake this fouth of July the port engine started to overheat. My first thought was I had rubber impeller parts in the cooling system. I didn't find any anywhere. So I thought the thermostat was bad I removed the thermostat and checked the housing for blockage. Since I was on the lake I tried running without the thermostat. Still overheating. I flushed every hose that I could and didn't find and blockage. When I run the engine with a garden hose it seems to be fine water flows through the engine normally until it heats up to about 175 and then flow stops. If I allow the engine to cool it flows fine untill it heats up again. I'm stumped!

 

[stub756]

Re: Volvo Penta 5.0 GL

I have a similar problem with my 2.3 cobra. At speed it runs coool but if i let slow it down and idle it will overheat. Mine runs fine on ear muffs as well. I am replacing the impeller. Did you lube the impeller before you put it in?

 

[grandefermagio]

Re: Volvo Penta 5.0 GL

No I did not lubricate the impeller but I did remove the housing and inspect it. It seemed to be OK. I checked the flow through the impeller and it also seemed to reasonable. I'm still stumped.

 

[stub756]

Re: Volvo Penta 5.0 GL

IF you didnt lube the impeller before you put the new one in that may be your problem. It is possible you fried your new impeller in the port side engine.