Pulley Noise? Fan Clutch Noise?

timmytoast

Test Drive
I have this squealing, metal-on-metal sound I think is either from a pulley bearing going out or the radiator fan clutch going out. I’ve already replaced the idler pulley and belt tensioner after spraying them with lube to determine what one is making the sound. When spraying them I started with the belt tensioner then moved to the idler pulley. After spraying the idler pulley the sound went away. So as I said I replaced the idler pulley and belt tensioner but the sound is still there. To sound is heard beginning at 2750-3000 rpm.

If someone can tell me how to post a video, if that’s possible, you can hear the sound in the video. Otherwise, any help anyone can give is welcome. Thanks!
 

TerryD

Total Tease
Supporting Member
Location
Covington, Va
If you slowly increase throttle to maintain the RPM around that level, it's the noise present or just when revving?
 

timmytoast

Test Drive
If you slowly increase throttle to maintain the RPM around that level, it's the noise present or just when revving?
It’s mainly present when revving but can also be heard when slowly increasing throttle. When slowly increasing throttle you can get to 4000 rpm or so before hearing the squealing sound vs 2750-3000 rpm when revving before hearing the sound.
 

TerryD

Total Tease
Supporting Member
Location
Covington, Va
Take your belt off and try it. Verify it's related to the accessories.

There's the fan mount to consider too. It's basically another idler pulley.
 

timmytoast

Test Drive
How long is it safe to run the engine without the belt?

With the belt off, if I don’t hear the squealing sound, what would that tell me? That the fan mount is bad?
 

TerryD

Total Tease
Supporting Member
Location
Covington, Va
How long is it safe to run the engine without the belt?

With the belt off, if I don’t hear the squealing sound, what would that tell me? That the fan mount is bad?
The water pump is run by the timing chain so till it needs the fan to cool. 5 minutes probably wouldn't hurt. Just watch the temp because without the fan spinning it could overheat eventually.

If it goes away, it could be any of the accessories. You'll just have to spin them and listen for noise or roughness in the bearings. If you have to change the fan clutch or mount, change them both because vibration from one will damage the other.
 
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