My SA began to make this obnoxious whining noise last night on my way home from work. Thought it might be a pulley bearing at first, but it's coming from the intake. Drove it around the block after I got home and seems to run fine. You can notice from the video that when I give it some gas the sound weakens but then returns to it's normal pitch. I thought it was a bad pulley bearing, but I'm not certain. Any help is appreciated.

http://www.youtube.com/watch?v=moaUs...ature=youtu.be

 

compared to what the last one sounded like I would say your exhaust is plugged .

 

Damn that's annoying...

To tell if it is the water pump or alternator, take off the belts and start it for a few seconds. Don't let it run for any amount of time without the water pump being driven.

 

Based on how it dips when you rev it, I'd guess it's vacuum related. Something acting like a whistle as air is pulled past it. Vacuum dips when you rev.

Use a cardboard tube to listen thru, and you can probably localize it a bit better because the tube will be directional. you can also pull and cap vacuum lines one at a time to see if it will go away.

 

Divin is right...def vac related.

 

Haha i know, my last video had a massive leak. Stud on the presilencer broke off so it was shooting out of the header. Got it welded for 15 bucks and it's been quiet ever since, until this annoyance that is.

Divin thanks for the input, I am going to take a look at it this afternoon. I wasn't sure if it was a pulley bearing or due to the strange pitch and because I would expect a bad bearing to get louder as it cranks faster. As of now it's similar to deflating a balloon while pinching the ends so a vacuum issue seems more probable.

 

Could be a vac hose, a gasket, or a torn diaphragm on one of the vacuum actuators (like the choke pull-off, shutter valve diaphragm, etc) if you still have them.

A bearing I'd expect the pitch to rise proportional to engine RPM.

 

*Face palm*

It was the gasket I put on under the block off plate... A slit ripped in it and it was flapping much like the balloon reference I brought up earlier. Thanks for the help!

 

[painting another dead bug on the side of my monitor]

Glad to help.

 

That noise was a vacuum leak? Damn, how far did you have to drive with the noise?

 

mine did that and it drove me crazy! it was the thingy above the exhaust manifold was loose lol

 

Too funny! If I was a hundred miles from home, I'd have to get ear plugs or get the car towed. With my luck it would be at night and for some reason I wouldn't have my tools.

 

For a next time diagnosing a pulley/belt related problem take the belts off or use a small amount of brake clean on the pulleys/belt. If the noise goes way you got a general idea of where to start looking or not looking.

 

My first thought after watching the video is that it might have something to do with that Frisbee that is lodged on top of your carb.

Does the car start running rough at idle when this started? If so, might be the shutter valve.

 

I drove to work and back one day... worst day ever.

 

Yeah I did that the first time i actually had time to work on it. I worked a double back to back days and my first chance was Wednesday after my shift. I kinda figured it wasn't a pulley since it did not get louder as i went faster. It' ran fine the whole time. There was just a half in slit in the gasket that was flapping. I had no idea what on earth could even make a sound like that haha.