So, I had blown a turbo coolant hose. This caused the car to sit until I had time to fix the issue. After having gotten everything back together, the car makes a distinct buzzing sound from under the UIM from 2000-3000rpm on accel and decel.

The car sat for 3 or 4 months, and also puked coolant all over itself in the process. Searches for buzzing return results about ISC's and bad injectors. Could there be air in the fuel lines, or a bad solenoid? Any other ideas?

Other than some buzzing the car runs strong. Idles a little high...maybe...

 

Sounds basically like the same problem i have. Starts fine and sounds like its running right. But from 1300-2500 i hear a buzzing or whistling sound coming from the same area as yours.

Does the sound go away when u rev up the motor?

 

Do you have an aftermarket boost controller? I've seen some Profec boxes make an annoying clicking noise under boost.

 

No, no boost controller. Although, it does come from right around the turbo solenoids bolted to the UIM. If it were a solenoid you'd expect it to crap out eventually.

It almost sounds like the airpump moo, but more baseball-card-in-tire-spokes/arcing-electricity. If only car-talk were still on the air....

I'll try swapping out those solenoids, but I wonder if I haven't misconnected something.

 

Quick check just unplug them but I doubt that's it

try unplugging various relays as well like the fans etc...

 

This sounds like your idle air control (IAC) valve. It can make a very noticeable buzzing sound when it goes bad or needs to be serviced....and it is located on the rear of the UIM. This has happened to my car as well. Just remove the IAC and liberally clean the inside of the valve with WD-40 and maybe some low psi compressed air. Make sure all of the dirt and crud is out. The buzzing sound can be the result of the solenoid trying to open or close a valve that is jammed up. Let me know if this helps. FYI: If you unplug the IAC, the car will not run.

Steve

Edit: One more thing...If you test the IAC per the factory service manual (page F-83) and get a good ohm reading, this doesn't mean there is not a problem with this part. The FSM only tests the coil, not the free movement of the valve.