454 Mag Belt Squeeking

[2ifbyc]

Hey All,
I have a 1990 7.4L 454 mag. I just got the boat and engine this year. I noticed today at the dock when i start the boat and rev the engine a bit in neutral it squeaks very loud. When i go back to idle its quiet again. Im assuming its one of the belts. Im not much of a mechanic so I guess my question is, where do I begin? How do i find out which belt it is (if it is a belt at all) and then how do i remedy the problem? Also, do I need a water pump? How do you know when you need to replace one?

 

[cr2k]

Re: 454 Mag Belt Squeeking

The squealing is either the PS pump or the Alt. belt. your pullys may be work smooth. Usually the Alt belt will squeal when you first start it when it tries to recharge the battery. You might check the tension. I find 90% of boats have loose belts cuz no one ever checks them. DO NOT over tighten or you will be replacing the alternator, PS pump and or Circulation pump due to bearing failure.

How do you know when its time to replace the raw water impeller?
If the boat is new to you you might want to do it now if you have no knowledge of when it was last done. This is a every 2 year replacement if you use the boat OR not. if used they wear if not used they sit and get hard and get a set to the vanes. usually first sign is heating at idle and ok under way or ok at idle and heat under way, depending on the plumbing and the boat.

 

[triman]

Re: 454 Mag Belt Squeeking

Not sure about the specifics of your engine, but if it has a serpentine belt it probably has a tensioner pulley. The bearings on these pulleys often get a bit squeaky. Simple job to replace them.
As for finding the source of the squeak, I use a long-handle, tang-through screwdriver as a stethoscope. The blade end on the object being tested, the handle end to an ear.
I use a long-handle screwdriver as it keeps hair and other easily caught bits away from the rotating stuff.

 

[2ifbyc]

Re: 454 Mag Belt Squeeking

Thanks for the advice guys!