Am I going crazy?

[ColinP]

I inspected the impeller on my Mercruiser 350 and everything was good. Reassembled the whole bit and got back out on the water and immediately heard a lot of squeaking noise coming from the raw water pump housing.

I reduced the serpentine belt tension a lot and the noise stopped, but now my concern is the low tension on the belt. I noticed that it does not take a lot of belt tension to make the pump assembly deflect and the belt tension is a lot less than it is on any of my cars, is that normal? I'm guessing I can deflect the belt at least 1.5" on the longest span. If I tighten the belt more, the pump gets noisy. Should I be concerned or am I just trippin?

[Bill_AirJunky]

Sounds like the bearings in the pump are on their way out. Might be time for another one soon. If so, I believe they have a weep hole that will start leaking.

Edited August 2, 2010 by Bill_AirJunky

[EchelonMike]

I inspected the impeller on my Mercruiser 350 and everything was good. Reassembled the whole bit and got back out on the water and immediately heard a lot of squeaking noise coming from the raw water pump housing.

I reduced the serpentine belt tension a lot and the noise stopped, but now my concern is the low tension on the belt. I noticed that it does not take a lot of belt tension to make the pump assembly deflect and the belt tension is a lot less than it is on any of my cars, is that normal? I'm guessing I can deflect the belt at least 1.5" on the longest span. If I tighten the belt more, the pump gets noisy. Should I be concerned or am I just trippin?

I replaced the top serpentine belt pulley on my Mercruiser 350 (top of engine, starboard side) and that solved my squeaking issue. Skidim stocks it. If the belt is skipping or "hopping" a bit when you blip the throttle, you have too little tension and you're going to throw a belt or lose traction on an accessory.

-- Mike