Engine "chirping" noise

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Jul 19, 2015 | 03:53 PM

Mpls Funk

Thread Starter

Burning Brakes

Joined: Oct 2000

Posts: 877

Likes: 59

From: Minneapolis, MN USA

Engine "chirping" noise

Hi all,

I have a 1970 with the 350/350. It has a Holley 650 DP carb and an Edelbrock Torker intake and a non-stock cam (don't know what it is, previous owner did it). At ~3000 RPM, the engine makes a loud high-pitch "chirping" noise. Is this the noise of the secondaries opening up? Is that common? When I pull the throttle by hand (removed the air cleaner), I don't notice this sound...but when I'm driving, it is very clear. Could there be something wrong, or is this normal?

Jul 19, 2015 | 04:32 PM

Revi

Drifting

Joined: Oct 2005

Posts: 1,615

Likes: 150

From: Forth Worth TX

Have you tried tightening your fan belts or replacing them if they are old?

Radiator fan hitting the shroud?

Jul 19, 2015 | 04:55 PM

gbvette62

Race Director

Joined: Oct 2000

Posts: 12,596

Likes: 3,082

From: Shamong, NJ

Quote:

Originally Posted by Revi

Have you tried tightening your fan belts or replacing them if they are old?

Do you have AC and/or power steering? Those belts love to slip and make noise, especially the AC belt.

Jul 19, 2015 | 05:22 PM

Mpls Funk

Thread Starter

Burning Brakes

Joined: Oct 2000

Posts: 877

Likes: 59

From: Minneapolis, MN USA

I have power steering, but no A/C. I'm not sure how old the belts are...prolly at least 5 years, but almost no miles in the past 5 years. Would it make sense that it only makes that noise at higher RPMs? When I first started driving it today, it would start making the noise at 2900-3000 RPM...after a little while, it would not start making the noise until ~3500-4000 RPM, don't recall exact number, but it was definitely a higher RPM.

Jul 19, 2015 | 06:36 PM

toobroketoretire

Melting Slicks

Joined: Apr 2009

Posts: 2,632

Likes: 112

From: Great Plains Iowa

Quote:

Originally Posted by Mpls Funk

As you're running a track-racing carburetor your secondaries open up at full throttle regardless of what road speed you're running or how fast you're spinning it. A loud high-pitched "chirping" would indicate a slipping alternator belt.

Jul 19, 2015 | 07:46 PM

Street Rat

Le Mans Master

Joined: Aug 2010

Posts: 5,339

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From: Central Texas

Sounds like an alternator belt to me too. Been there.

Jul 19, 2015 | 10:15 PM

Mpls Funk

Thread Starter

Burning Brakes

Joined: Oct 2000

Posts: 877

Likes: 59

From: Minneapolis, MN USA

Thanks guys - sounds like I should just replace the alternator belt. I'm sure this is an easy task - can anyone point me to a video or good "how to" post on how to do it properly?

Jul 20, 2015 | 12:39 AM

Mpls Funk

Thread Starter

Burning Brakes

Joined: Oct 2000

Posts: 877

Likes: 59

From: Minneapolis, MN USA

Based on your comments above, I tool a look at my belts and was surprised to see my alternator belt is touching/rubbing on the front of the power steering pump! Could this be part of the issue? But again, I ask why only at higher rpms? I tried to get a picture of it. The first picture is zoomed out to give perspective...the second picture is trying to show closer up:

It appears I can take tension off the alternator belt by loosening one of the alternator mounting bolts and then sliding it along that bracket. But how do I take tension off the power steering pump belt (the one closest to the fan) to replace that?

Last edited by Mpls Funk; Jul 20, 2015 at 10:17 AM.