Let me first clarify that I seriously doubt that this is the belt because this sound is unforgivably LOUD... It was heard by people inside a large biulding!

Whats happening is this... SOMETIMES, not always but occasionally when I start my car up, I hear something whine like an intense grind... It literally sounds like an alarm or a sirense (infact thats what I thought it was when I first heard it until I turned the car off and it too disapeared.) It will last for maybe a minute and won't even fade it just... vanishes, disapears, car runs like it never even experienced the problem. A local mechanic said it MIGHT be a pulley. Well just a few minutes ago I was (un)lucky enough to catch it again! I popped the hood immideately to take a peak. I looked at the belts and pulley's rotate and none seemed to wobble and infact, the noise level really wasn't as loud under the hood as it is inside the car... I look under the car and it is somewhat louder then I check behind the car and it seems to be the loudest right where the exhaust exits... What on earth does this sound like?

 

It's not the air pump going south is it?

 

I have the exact same problem you are talking about. When the car has been sitting for a long while, it doesn't make this noise on startup, but if the engine is still pretty warm when I start it up, it will do it. It goes away after a few minutes, but it really is as loud as you are making it out to be. If you bring the rpms up for a minute when it starts making this noise, it usually goes away. I haven't had a chance to mess with it yet, but I am pretty sure it is a pulley.

 

If you find out what it is, please inform me... For me it usually happens when I leave the car sitting for about an hour or two. It hasn't happened on a real cold or real warm start yet. All bets are off though. How can I tell if it's a pulley? Better question, how hard is it to replace those pulley's? If they are Pulley's, is this a good opportunity to go Underdrive?

 

How can I even be sure?

 

I think it's the starter failing to disengaging from the flywheel. Or rather the starter continuing to try and engage the flywheel after the engine has started.

 

Sounds logical to me. The fuel pump and trans pump are the only other things I would guess to look for as far as a whine coming from underneath/rear of the car. However, when it's as loud as you say it is, I'm going to have to go with the starter too. If it happens again, stick your head under the car (while it's secure of course) right behind the front passenger tire. You should be able to see the starter from there....and hear it the best from there as well.

 

If he is hearing the same sound as I am, this is not the problem.

 

If it's the starter, will replacing it fix the problem? Is there a possability I could have damaged the flywheel aswell? All I know is that it's an intense highpitched humming sound, it sounds almost like electricity and then after about a minute or so, it doesn't just wind down or anything it just disapears as if some mechanical device was disengaged...

 

If it were the starter it would actually be the solenoid on the starter freezing in the engaged position. As for the sound, the starter gear against the flywheel ring gear would make a racket that isn't so much a whine as a grind.

If it is the starter the flywheel ring gear is being eroded. Let's hope it isn't that. If it is purely a whine and not a screech then it is probably associated with the air pump as said. The pump runs for about a minute after start. Does that seem to be about how long you are hearing the noise?

 

Pull the AIR PUMP fuse under the hood to disable it.

 

If it were the starter, would it sound JUST LIKE holding they key in the "START" position while the engine is already running? That clicking sound? If it is, then fortunately thats not the same sound... It sounds more like a biulding alarm going off and when I say it's LOUD I mean it's LOUD!!! It only lasts for about a minute, maybe even less. It doesn't wind down or slowly fade, it just DISAPEARS INSTANTLY as if it were some sort of machine disengaging.

Basically...
- It sounds like a very loud whine.
- Pitch doesn't change regardless of the RPM or Gear I'm in.
- It only appears at Startup and not EVERY Startup either. I've only heard it twice this week. It never does it on Cold MORNING starts however after I've driven it, let it sit for about 3 hours, come back to start it and it usually happens.
- It seems to be the loudest INSIDE the car or where the exhaust exits, not under the hood.
- Disapears without even the slightest fade within a minute.

 

The only thing back there that would whine is the fuel pump.

 

Yes, it would sound just about exactly like you hit the starter while the engine was running. Didn't know anyone else ever did that.

If the sound is as loud as you're describing then I'm at a loss as to what it is other than to go stand with the others that feel it is a belt screeching. But a belt slipping over a pulley doesn't sound like a building alarm.

Stupid question but are you certain your car doesn't actually have an aftermarket security alarm system that is malfunctioning? My 95 has a remote start hidden in the dash that I have never been able to use but I wonder if some day someones transmitter will trigger it randomly.

 

The only thing on a car that I've ever had that kind of sound from is bad alternator bearings. Sometimes they'll scream like a banshee upon startup then go away 'till the next time. And the alternator is way down low in these cars so that could be why you can hear it so clear from the rear.

Pull the acessory belt and spin/wiggle every pulley, idler, and accessory and see if one feels gritty/loose.