Strange pulley noise...

[philmay75]

Hi, experts,

I have an 89 Galaxie 18.5' open bow with a 4.3L OMC V6 I/O (Model 432APRMED) motor.

It has had no real problems, rebuilt the carb this year, great power, and she is running across the water like a scalded cat. But this past week when idling I noticed it started making a sound coming from the front of the motor that is a little hard to describe, but it is almost like a scraping or brushing that goes faster and slower with the RPM...It's like a shh shh shh shh shh shh....(sorry, dont know how to better describe it. It doesnt sound high pitched like metallic scraping...and the noise comes and goes.

Also noticed what seems to be some belt dust gathering on the back of the couch (sits right in front of the water pump) and on the upper doghouse cover. The entire thing is pretty much original parts, and the clock says it has about 200 hours.

I am wondering if the water pump could be going out, or if there is a bearing/bushing in there that could be old and wearing out. Or if just bad belts could make that sound.

I try to work on this stuff myself as much as possible...I just wonder if anyone has dealt with something like this, before I go start dropping coin on a water pump, not knowing if that is the problem.

Thanks much.
-Phillip

 

[Scott Danforth]

Re: Strange pulley noise...

alternator bearing? pull the belt and start spinning components by hand.

 

[Larry E]

Re: Strange pulley noise...

Hi, experts,

I have an 89 Galaxie 18.5' open bow with a 4.3L OMC V6 I/O (Model 432APRMED) motor.

It has had no real problems, rebuilt the carb this year, great power, and she is running across the water like a scalded cat. But this past week when idling I noticed it started making a sound coming from the front of the motor that is a little hard to describe, but it is almost like a scraping or brushing that goes faster and slower with the RPM...It's like a shh shh shh shh shh shh....(sorry, dont know how to better describe it. It doesnt sound high pitched like metallic scraping...and the noise comes and goes.

Also noticed what seems to be some belt dust gathering on the back of the couch (sits right in front of the water pump) and on the upper doghouse cover. The entire thing is pretty much original parts, and the clock says it has about 200 hours.

I am wondering if the water pump could be going out, or if there is a bearing/bushing in there that could be old and wearing out. Or if just bad belts could make that sound.

I try to work on this stuff myself as much as possible...I just wonder if anyone has dealt with something like this, before I go start dropping coin on a water pump, not knowing if that is the problem.

Thanks much.
-Phillip

Water pump

 

[philmay75]

Re: Strange pulley noise...

alternator bearing? pull the belt and start spinning components by hand.

:facepalm: That's a really great common sense suggestion. Thanks, Scott. Will give that a try.

 

[paultjohnson]

Re: Strange pulley noise...

I have had good luck troubleshooting belt noises by spraying the tiniest bit of WD-40 on the belts while the engine is running. Like a half second...IF the sound is just the belt on the pulleys, the noise will go away instantly [tho temporarily] This is the best case scenario, a new belt may be all you need. Also, if a bracket or something has loosened up, the belt may just be out of alignment causing excessive wear. If the noise continues, the problem is deeper, like alt, water pump or power steering unit/bearings...Good luck...

 

[philmay75]

Re: Strange pulley noise...

Thanks, guys,

Honey-do's got me today, but I'm going to have a closer look tomorrow.

Seems like I've seen this type of question asked before, but can I put a chevy waterpump on this thing, or does it need to be marine? I can understand the marine-specific non-venting carbs and gaskets...wouldnt seem to matter with a water pump, tho?

 

[Scott Danforth]

Re: Strange pulley noise...

the circulating pump is the same between boat, truck, car, genset, and irrigation pumps.

 

[philmay75]

Re: Strange pulley noise...

Thank you all for the great suggestions.

As an update to this issue, I pulled the belts off the accessories leaving only the damper pulley to turn with the motor. I hand spun each of the components, but no sound like I was hearing. so I started the motor and sure enough I still get the brushing noise coming from the damper. (picture of the damper below). Not sure what makes a brushing/light scraping sound from the damper with no belts. Do they wear out and eventually brush against the crankcase? Gonna do a little research on the interweb to see what I can find out.

 

[Idlespeedonly]

Re: Strange pulley noise...

It is hard to tell in the picture But it looks like the outer ring has slid back. And if it has it is probably rubbing the timing chain cover.

 

[bruceb58]

Re: Strange pulley noise...

the circulating pump is the same between boat, truck, car, genset, and irrigation pumps.

It needs to be a marine pump especially if you are in salt water. Has a sealed bearing and a stainless steel impeller.

 

[philmay75]

Re: Strange pulley noise...

It is hard to tell in the picture But it looks like the outer ring has slid back. And if it has it is probably rubbing the timing chain cover.

Idlespeed...I think you are correct...I got the bracket out of the way and took a better pic (below). Looks like its time for a new one. My book says I have to pull the motor for that? Is that true? The front of the motor is very accessible.

 

[bruceb58]

Re: Strange pulley noise...

If you have room for a puller, there is no reason to have to pull the motor.

 

[Idlespeedonly]

Re: Strange pulley noise...

As long as you have enough access from the front, the motor will not have to come out. Just be sure to use a balancer remover and installer. Dont use a hammer and the center bolt to put it on. You can borrow these tools from most auto parts stores. Probably need a new seal while you are in there also. Now if the cover is wore through the motor will most likely have to come out to replace it. If it was wore through you would develope an oil leak. Be sure to paint the bare metal to prevent rust. One more thing, dont run it like that.

 

[philmay75]

Re: Strange pulley noise...

Thanks, Idlespeed and Bruce...grateful for the guidance. This will probably take me a few days/week to gather what I need and finish it.

"One more thing, dont run it like that." LOL, too true. You know how tempting it is. I doubt it wore thru...the sound started last time out and we haven't run it since. and no oil is leaking.

Thanks again, gentlemen. I'll post the update.

 

[robert graham]

Re: Strange pulley noise...

I have had good luck troubleshooting belt noises by spraying the tiniest bit of WD-40 on the belts while the engine is running. Like a half second...IF the sound is just the belt on the pulleys, the noise will go away instantly [tho temporarily] This is the best case scenario, a new belt may be all you need. Also, if a bracket or something has loosened up, the belt may just be out of alignment causing excessive wear. If the noise continues, the problem is deeper, like alt, water pump or power steering unit/bearings...Good luck...

My second on that method to determine if it's the belt or another component....belts can make all sorts of sounds and noises!

 

[philmay75]

Re: Strange pulley noise...

Hi guys,

It's done, surprisingly. I found an OMC damper here local, and the puller/installer at the auto parts store. Followed the guidance on here, and a youtube vid I found on using the tool, and there ya go. about 2 hours including painting the bare spot, put on new belts while I was in there, and she's ready to go again.

I very much appreciate you guys time and input. It was a lot easier job than it would have been if I didnt have the help. Thanks!

-Phillip

 

[Idlespeedonly]

Re: Strange pulley noise...

Looks good. It is easy with the correct tools.

 

[Darringer]

Re: Strange pulley noise...

An idea on the belt dust that you had in the doghouse. If the pulleys have rust in the "v" section, it will be rough and literally sand your belts down. The rougher they are, the worse and faster this will happen. I had the same problem and used a wire wheel in the "v" to remove the rust and make them smooth again. Problem solved.