overheating

[memaw777]

I have a 1978 Century 260 hp 350 V8. I lost abelt to water pump got so hot it started spark knocking. I shut it down and replaced belt after it cooled down I started it up there a loud squeeling from the water pump. While I had the belt off I tried turning water pump by hand and it really spun easy which didn't seem right. But it still got hot when I took pump of I couldn't find anything wrong turned free and all the fins looked good. Any help will be appriciated.

 

[arboatdr]

Re: overheating

I assume you are talking about the engine circulating pump turning free. If so I would look at the impeller in the lower unit. If you are talking about a seawater pump then it should not turn without some resistance. If it turns freely,take it apart and check your impeller agian looking for a spun hub or badly formed fins. As far as the squeeling goes, isolate the noise and replace the damaged component. Good luck, DH

 

[Don S]

Re: overheating

What do you have, OMC, Mercruiser, Volvo???

 

[memaw777]

Re: overheating

sorry its a mercruiser

 

[Don S]

Re: overheating

How about raw water cooled, or closed cooling system. (Do you have a heat exchanger that also holds antifreeze.)<br />With a serious overheat, you may have damaged the thermostat.<br />Do you have raw water flow through the cooling system. If the boat is out of the water, is there water coming out of the transom shield relief ports. If still in the water, do the risers get hot quickly (10 ro 15 seconds)?

 

[memaw777]

Re: overheating

yes raw water cooled with new manifolds and risersI dont know about transom shield relief ports the recirculating pump was squealing took it off couldnt find anything wrong also had broken belt

 

[Don S]

Re: overheating

If the pump turns free, are you sure that is what is causing the squeeling belt? Did you check the alternator, if it's froze up the belt will squeel and the pump won't turn.

 

[waterone1@aol.com]

Re: overheating

Just wondering, are you sure it's the BELT that is squealing ? It could be the bushings in the circulating pump shaft. If the bushings are worn, they will seam fine when turning by hand, untill you get to the speed an engine turns. In that case replace the pump.

 

[Walter]

Re: overheating

You can determine if the belt is squealing by using a spray bottle to squirt some water on the belt and see if the noise goes away. (Obviously, the engine must be running!) If it does...you can feel quite confident it's the belt that's squealing.<br /><br />Also...I wouldn't hesitate replacing the engine's thermostat after a significant overheat.<br /><br />Walt

 

[deputydawg]

Re: overheating

OK, I must ask, what happened to the belt in the first place? Is there something else locked up that caused it to throw the belt? If a belt is adjusted correctly and everything is good belts just don't come off. Find what caused the belty to lose in the first place, you may solve your problem. <br />If you put the same belt back on is it stretched and slipping?

 

[crazy charlie]

Re: overheating

When was the impeller in the outdrive replaced last?????I would spend the $100 bucks and replace the circulator too.Sooner or later you will have to anyway.Call it Preventative maintanence.Charlie

 

[memaw777]

Re: overheating

I have a new recirculating pump I was going to put a new impellor in lower unit when I pulled lower unit down there was water on the splined shaft where it goes into upper unit. Is this a problem does the seal up inside have to be replaced if so how.