After the car has been shut off, the IAC Solenoid still has power to it - full battery voltage. Is this normal? Is the main relay f'd? I didn't see how many amps it was pulling.

The problem may be due a problem in the alternator. With the engine off, disconnect the smaller wires on the backside of the alternator and see if the problem clears. If it does you need to replace the alternator. A isolation diode in the alternator has shorted. Be careful when working around the main output lead of the alternator since it is hot to the battery. Disconnect the battery ground lead first if you need to remove the alternator.

At first I thought it was the alternator so I disconnected that connector. I could still hear the buzzing of the solenoid.

Could it just be a dirty/sticking valve?

Could it just be a dirty/sticking valve?

 

It wouldn't cause this to happen. We need to find the source of the power getting to the valve. It would help to know the model and year of the vehicle with the trouble.

 

To help disconnect the circuit when the car is parked find out which fuse the circuit is on by pulling fuses one at a time.

It's a 1995 Legacy with an EJ22 engine. The circuit is powered through the main relay and a 30A fuse in the main fuse box. I don't have the wiring diagram in front of me so I can't remeber what other sensors/instruments are also on that circuit.

 

I was having a previous problems with the car which I traced to a loose ground wire on the intake manifold.

 

I'm also loosing coolant. Is it possible there's a crack in the valve body and coolant is getting into the intake manifold?

The main relay should open up when the ignition is off. Check to see if the relay is staying closed. Another possibility is the ignition switch isn't turning off as it should. Pull fuses out to see if you can isolate the bad circuit path that way.

 

I doubt that there is a coolant leakage problem causing this to happen. You may have a headgasket or intake manifold leak. First be sure that that there isn't a loose connection somewhere and check things while the system is hot and engine is running keeping pressure up.

Both my dad's 95 2.2 and my mom's 98 2.5 do this. They shut off after a little bit. Had me worried the first time I noticed. Not sure why it does this, but it's just the way it works.

Thanks