Horrible whining sound under hood - The 1947 - Present Chevrolet & GMC Truck Message Board Network

DancingAvocado · 11-11-2021, 07:13 PM

This is on my 72 C20 I recently got. Last owner said it sat for 12 years. I cleaned the tank and lines, put new belts, charged battery. I got it running, and I have a weird sound.

I think one of the pulleys is bad, but it I never had a bad pulley sound like this before. It was very loud. I can't feel any play on the pulleys by hand.

https://imgur.com/a/tvPV5E1 You may have to click unmute on the video, it does have sound.

**LockDoc** · 11-11-2021, 07:17 PM

Quote:

Originally Posted by DancingAvocado

This is on my 72 C20 I recently got. Last owner said it sat for 12 years. I cleaned the tank and lines, put new belts, charged battery. I got it running, and I have a weird sound.

I think one of the pulleys is bad, but it I never had a bad pulley sound like this before. It was very loud. I can't feel any play on the pulleys by hand.

https://imgur.com/a/tvPV5E1 You may have to click unmute on the video, it does have sound.

Bearings may be dried out in the alternator or water pump.

LockDoc

purple gas · 11-11-2021, 08:02 PM

did you loosen the belts and try spinning some pulleys by hand?

**71CHEVYSHORTBED402** · 11-12-2021, 12:17 AM

Quote:

Originally Posted by LockDoc

Bearings may be dried out in the alternator or water pump.

LockDoc

I was thinking water pump, but yeah.

**Stocker** · 11-11-2021, 09:05 PM

If you don't have a mechanic's stethoscope, you can place the handle end of a long screwdriver against your temple, then touch the other end on various parts. Water pump, alternator, PS pump...... be careful you don't touch any moving parts like belts, pulleys, or the fan. Should be able to isolate the noise.

I have also read you can do the same with a few feet of vacuum hose, but I've never tried that.

garyd1961 · 11-11-2021, 09:32 PM

You can also take the belts off and run it for a minute. If the sound goes away you know it's not internal and is something running off the belts .

**knuckle-nurse** · 11-12-2021, 12:10 AM

I had a horrible whining sound inside my cab the other day but it went away when I dropped the cluck off at the hairdressers.

Redneck Rydes · 11-12-2021, 06:14 AM

Quote:

Originally Posted by knuckle-nurse

I had a horrible whining sound inside my cab the other day but it went away when I dropped the cluck off at the hairdressers.

I can relate,15 hours non stop in the truck,OH MY

Lethal Tendencies · 11-12-2021, 07:56 AM

Quote:

Originally Posted by knuckle-nurse

I had a horrible whining sound inside my cab the other day but it went away when I dropped the cluck off at the hairdressers.

BigBird05 · 11-12-2021, 09:49 AM

Do you have power steering? Could be low on oil.

rockyrivermark · 11-12-2021, 04:20 PM

Pretty easy to diagnose when it's that bad. like others already said, pull the belts and turn things by hand.
I'd bet a 12 pack of long necks it's water pump.
RRM

**Palf70Step** · 11-12-2021, 05:57 PM

Have you tried a stethoscope (harbor freight has decent one cheap). Sure makes finding the noisy item quicker than throwing money at parts.

11-11-2021, 07:13 PM	#1
DancingAvocado Registered User Join Date: Jul 2021 Location: Marthasville, MO Posts: 5	Horrible whining sound under hood This is on my 72 C20 I recently got. Last owner said it sat for 12 years. I cleaned the tank and lines, put new belts, charged battery. I got it running, and I have a weird sound. I think one of the pulleys is bad, but it I never had a bad pulley sound like this before. It was very loud. I can't feel any play on the pulleys by hand. https://imgur.com/a/tvPV5E1 You may have to click unmute on the video, it does have sound.

11-11-2021, 08:02 PM	#3
purple gas Registered User Join Date: Oct 2004 Location: saskatoon, planet earth Posts: 694	Re: Horrible whining sound under hood did you loosen the belts and try spinning some pulleys by hand? __________________ I got a bench seat baby, you don't have to sit over there.

11-11-2021, 09:05 PM	#5
Stocker 20' Daredevil (Ret) Join Date: May 2003 Location: Jefferson State Posts: 13,691	Re: Horrible whining sound under hood If you don't have a mechanic's stethoscope, you can place the handle end of a long screwdriver against your temple, then touch the other end on various parts. Water pump, alternator, PS pump...... be careful you don't touch any moving parts like belts, pulleys, or the fan. Should be able to isolate the noise. I have also read you can do the same with a few feet of vacuum hose, but I've never tried that. __________________ - Mike - 1972 K20 LWB 350/350/205 RIP El Jay

11-11-2021, 09:32 PM	#6
garyd1961 Registered User Join Date: May 2016 Location: Henderson NC Posts: 975	Re: Horrible whining sound under hood You can also take the belts off and run it for a minute. If the sound goes away you know it's not internal and is something running off the belts .

11-12-2021, 12:10 AM	#7
knuckle-nurse Senior Member Join Date: Jan 2009 Location: Tugaske SK Canada Posts: 304	Re: Horrible whining sound under hood I had a horrible whining sound inside my cab the other day but it went away when I dropped the cluck off at the hairdressers.

11-12-2021, 09:49 AM	#10
BigBird05 Registered User Join Date: Aug 2019 Location: Cheraw Posts: 1,300	Re: Horrible whining sound under hood Do you have power steering? Could be low on oil.

11-12-2021, 04:20 PM	#11
rockyrivermark Registered User Join Date: Apr 2011 Location: Fairview Park, Ohio Posts: 1,031	Re: Horrible whining sound under hood Pretty easy to diagnose when it's that bad. like others already said, pull the belts and turn things by hand. I'd bet a 12 pack of long necks it's water pump. RRM __________________ My build page http://67-72chevytrucks.com/vboard/s...d.php?t=764662 My cabinet building site http://www.cbcabinets.com

11-12-2021, 05:57 PM	#12
Palf70Step State of Confusion! Join Date: Jul 2002 Location: Gulfport, MS USA Posts: 47,083	Re: Horrible whining sound under hood Have you tried a stethoscope (harbor freight has decent one cheap). Sure makes finding the noisy item quicker than throwing money at parts. __________________ Bill 1970 Chevy Custom/10 LWB Fleetside 2010 Toyota Tacoma PreRunner SR5 Double Cab - DD Member of Louisiana Classic Truck Club (LCTC) Bill's Gallery Life isn't tied with a bow, but it's still a gift. Live simply. Love generously. Care deeply. Speak kindly. Leave the rest to God!



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