slight overheat problem..waterpump???

[JoelF]

260/350 Mercruiser. I put a new thermostat in last year and everything was ok all year. Today I put the boat in the water and at idle the temp gauge does up to 180 Degrees. With a little throttle the the temp gauge goes right down to about 160 and stays there while underway. Does it sound like I need a new water pump impeller?????????

 

[180shabah]

Re: slight overheat problem..waterpump???

Sure does

 

[Don S]

Re: slight overheat problem..waterpump???

260/350 Mercruiser

For future posts, that discription says absolutely nothing about what you have.
Year, actual model number, and best of all the Merc SN and what drive you have is the information needed for many/most problems. You may not see how the type drive effects your problem, but trust me, it can.

 

[JoelF]

Re: slight overheat problem..waterpump???

Its a 1984 with 350 hours, alpha drive. I'm not able to get the model and serial number until next week.

 

[Haut Medoc]

Re: slight overheat problem..waterpump???

With that info, it does sound like you need a new impeller....
If you haven't had your drive off, there are othere things to be serviced at the same time....
Here is a link to manual #6.....
http://www.boatfix.com/merc/Servmanl/6/6covr3.pdf
Courtesy of Don S....
This will give you the procedure for the task......​