[agrajeda]

Hello everyone, my Dad left my Sister and I a Chevelle after he passed away a couple years ago. Still learning about the cars. We noticed a strange engine noise. Can anyone help me figure out what this is? I really appreciate any help.

1970 Green Chevelle

 

[SFD]

Sounds like something vibrating maybe on that pulley system or possibly a water pump going bad. Other guys on here may know once they hear it. Sorry about your dad.

 

[Leadhead]

I was think it was a rattle also, but the engine idle seemed to struggle as the rattling got louder toward the end of the video. I'm starting to wonder if you dropped a valve.

 

[agrajeda]

Thank you. Any suggestions on process of elimination? Should I replace one part at a time?

 

[Leadhead]

I wouldn't take my word on it. There are people here that are infinitely smarter than me. I would wait for more responses. I would take a section of hose and put one end up to your ear, and put the other end up against the valve covers, and move it along each one to see if the problem area presents itself.

 

[Leadhead]

Also wondering about a loose timing chain. Does the car start back up easily after it stalls?

 

[agrajeda]

My sister says she starts it and then around a minute and 15 seconds it starts to make the sound in the video then the engine shuts off.

 

[agrajeda]

Yes it starts up easily.

 

[Leadhead]

Do you have any black smoke coming out of the exhaust?

 

[agrajeda]

No black smoke. Here is a 2nd video. Car is staying on now.

1970 Chevelle Engine

 

[Leadhead]

You know what, I just noticed that you have an electric fan for your radiator. I'm starting to think it's the bearings in your fan. Try unplugging the fan and see if it still does it. Just don't let it run too long to where it overheats.

 

[Leadhead]

Let me know the results.

 

[agrajeda]

Will do.

 

[oldcutlass]

Also take the belt off and see if the noise goes away.

 

[hydro462]

Thats what I was thinking, one of those electric fans with the cheap bushings. I know that sound but I just can't remember what it was..

Fuel pump drive?

 

[agrajeda]

We are going to test it tomorrow. I will let you know if that fixes it.

 

[DUTCH MAX HEADWORK]

Grab the air cleaner and see if the rattle stops. At the end of the first video, you can see the air cleaner assembly is loose and rattles around.

In the second video, That pump on the left front side is a vacuum pump for the vacuum brake assist. It turns on to supply vacuum to the brake system then turns off when a set limit is reached. The noise it is making is normal. They are loud.

 

[LeoP]

JMHO, sounds like the water pump to me, do take the belt off and run it without and see how it sounds then and good luck!!

 

[DUTCH MAX HEADWORK]

JMHO, sounds like the water pump to me, do take the belt off and run it without and see how it sounds then and good luck!!

It does sort of sound like a water pump bearing going bad, But I'll double down on a loose air cleaner housing. My car makes the same noise when the top of the air cleaner is not tightened down enough.

 

[marcrose]

As stated take the belt off