strange humming

[PhantomZ28]

ok i got a 97 lt1 and i'm wondering about this strange humming noise when ever i turn off my car.
ok i turn the key to the run position but do not sart right?
then when i turn the key back to off i hear this humm (i think it a fuel pump?) from right infromt of the drivers seat.
i'm jsut wondering what it is and where its located?

[TruckMuddr]

Does your radio and stuff still work when you turn the key to off???

[PhantomZ28]

yup
everything is normal my friend i had a 2nd fuel pump installed? O.o?? i dont think so. but the reason i ask what it is is cuz at time it dosent make that humm it makes a clanking noise and that just worries me!!

[TruckMuddr]

Hmm, thats weird

[Dave M]

This may sound weird, but are you sure it's not your power antenna going back down? After you turn the ignition off, the power antenna retracts into the fender, and the motor hums. Because the car is off and quiet, it's very noticeable. It also clanks as each section goes into the other. Sounds like it may be exactly what you're describing. It wouldn't be coming from in front of the drivers seat, but the sound may fool you.

[jspeed97]

I have a 97' Formula that when i turn the key and then turn it back off without ever starting it, the A.I.R pump will run for a second. That is the pump that pulls the exhaust gases to be recycled into the engine. For some reason, don't know why, it decided it would start doing that. Of course it doesn't hurt the car and it only does it when I turn the key and then turn it off without starting the car.

Reason I know this, is because I was putting in my K&N FIPK 2 intake and I had to re-attach the AIR hose to the new intake, just infront of the MAF sensor. When my buddy turned the key on and then off I heard it run and saw exaclty where it was coming from. I thought to myself, that is weird. So to make sure, I got under the car, unconnected the AIR power, and had him do the same thing. It didn't run, so I knew it was the culprit. I've had a few LT1s and never saw this happen before, but I wouldn't be to worried.

Check it out for yourself, but be very careful in the process.

[PhantomZ28]

yeah its not a power antenna (dont got one)
but i'll check that air pump. i hope thatswhat it is. it dosent seem to affect my engine when it doesnt happen. but i'll take a look andsee. just making sure the air pump isnext to the igniton coil right?

[jspeed97]

Okay, if you get up under the car on the drivers side, just in front of the wheel well, and look just under the drive pulleys, you will see it. You can see all of the EGR (AIR) hoses connected to it. You can't miss the simple 2 prong power connector, it looks exaclty like all the other snap power plugs. If you have trouble finding it, simply follow the AIR pre-maf hose back down to it. Hope this helps. I'm not a mechanic, so I might not being using the incorrect terminolgy, but I'm sure you will see what I am talking about. Let me know if it is it.

I've thought about removing the entire system to save weight, but didn't want to trip any computer codes...... Oh well, I'm trying to sell my baby anyway.... Hope this helps though....