Logo
FULL SITE MENU

rattling noise at rpm increase

P

Patrik Falk

New member
after launching the boat this summer the motor gave off a high rattling/metallic noise when increasing the speed on two occasions after around 5 minutes of hitting the seas. I couldn't reproduce the noise, but I took off the hood and filmed the minutes after. Seems the circulating pump pulley is sounding a bit wobbly so I plan to change the circulating pump in the hope it's the bearing giving in. I can see a small leak (a couple of drops in total) from the seals on the lower end of the circulating pump housing. (Mercruiser sterdrive, 5L, 305 CID)

http://www.youtube.com/watch?v=emY2Xh0fSH0


any ideas?
 
Last edited:
Master mechanic said:
Didn't look at the video but if it leaks it's bad bearing went also a auto one will work also with bronze / brass vanes or ss.
Click to expand...

Yup..... Sounds like bearings are junk and the circ pump is headed to the scrap bin. As soon as you see a few drops of water from the "weep hole" in the pump, that's an indication it doesn't have long to live. Be sure you have a "Marine Rated" circ pump, as it will have a bronze / Stainless Steel impeller AND a stainless Steel back cover. Automotive ones will rot out in no time flat, unless you have closed cooling (antifreeze in block), then an automotive pump can be used..
 
Back
Top