Lower pressure from water pump after impeller change

[seaway81]

I ran aground last week (inside a channel, by the way) and managed to suck a great deal of sand into the impeller housing of a 1999 Mercury 60HP Bigfoot. As a result, the engine barely pumped any water so I took it in to a shop to have it looked at. In short, the impeller housing was completely clogged with sand. I had the housing, the base plate and the impeller changed. After the repairs, the engine pumps water, but at a much lower pressure than it did before I ran it aground. The mechanic seemed to think it was fine, but I am a bit worried. After running the engine for a half an hour at varying RPMs under load the water "peeing" out is warm, but far from hot, and none of the egine surfaces feel more than warm to the touch. Should I be concerned? Is there a period of time befor the new impeller "seats" itself in the housing? Thanks in advance for any help or guidance.

 

[seaway81]

Re: Lower pressure from water pump after impeller change

Anyone have any ideas? I need to get back to fishing!! Thanks.

 

[j_martin]

Re: Lower pressure from water pump after impeller change

Maybe if you told us what the pressures were and are, someone could offer an intelligent opinion.

I'd hazard a guess that the mechanic cleaned out some other partially plugged passages, and it is now normal instead of slightly high as before.

That's just a guess, because you have given me no factual information.

hope it helps
John

 

[hkeiner]

Re: Lower pressure from water pump after impeller change

Is there a period of time before the new impeller "seats" itself in the housing?

A new impeller works at it's best right after installation. There is no break-in period before the water pressure is at it's maximum potential.

If you decide to hook up a pressure gauge, the below guide may be helpful.

 

[marty53]

Re: Lower pressure from water pump after impeller change

Yea there isn't any break in time with an impeller. I'd say contrary to j_martin that it's possible when you sucked in the sand that sand got suck up in the water line elsewhere, which the mechanic didn't clean out when he change the impeller and housing, and thats restricting the flow. I would have him check it out. or you can blow air through it with a compressor.

But as j_martin said. you can put a water gauge in for $50 if you dont already have one--then you could get some real answers

 

[seaway81]

Re: Lower pressure from water pump after impeller change

Thanks for the help. Too bad j_martin needs to be a prick about it. sorry I didn't include the correct amount of factual information. Sorry I don't own a pressure gauge. I was under the impression that people with limited knowledge could come here, ask questions of those with a good amount of knowledge and get helpful responses without getting a bunch of attitude as well. I now know I was incorrect.

 

[j_martin]

Re: Lower pressure from water pump after impeller change

EXCUSE ME!
How did you know that the pressure was lower without owning a pressure gauge? Thus I assumed you had information that you didn't disclose.

If by pressure, you meant the force of the telltale stream, then that makes sense. The water at the telltale all has to go through the thermostats. If they are working properly, and the engine is getting good supply, the telltale is normally quite scant and intermittent. If it is strong all the time, you're probably slightly overheating.

If I were the prick you claim, I'd just ignore you like all the others did for 24 hours, and let you go on spending good money chasing a non-problem.

I'm done guessing/helping. Good luck

John

 

[seaway81]

Re: Lower pressure from water pump after impeller change

I guess you got me straightened out. I would like to apologize, j_martin, it seems I am not having the best of days and took it out on the only person trying to help. For that I am sorry. And thank you for your help.

 

[j_martin]

Re: Lower pressure from water pump after impeller change

Accepted, all is good.

If you need any more help, just ask.

John