I promise this isn't like all the other blower motor threads out there!

Here's the sequence:
1) Heard chirping noise commonly diagnosed as bad blower motor. Noise typically stopped when fan turned off.
2) Removed, cleaned, re-installed blower motor.
3) Chirping came back, but ONLY chirps from ~40-65 mph. Did not stop when blower motor turned off.
4) Removed blower motor again.
5) Chirp is still there, only from ~40-65 mph (without the blower motor installed).

Since the chirp doesn't occur except for a certain speed range, I'm thinking that either the ram air pressure at that speed or some sort of vibrational resonance is rattling something in the dash. Is there something specific I should check before tearing apart the dash?

P.S. Drive shaft rebuilt last week. So don't even go there

 

blend door actuator? You might be able to pull glove box and get at one side, and maybe see from the other side without pulling dash, perhaps some silicone spray could reach it.

Also, the fresh air intake from under the hood cowl comes straight down to the fan location, and could have leaves it it. I shoved a piece of that rough plastic spun air filter material in mine to keep out some of the billions of live oak leaves we get in my area.

 

And recirculation flap, which has an actuator servo, get at it from glove box, see page 1174 of 1529 in the RAVE shop manual.

 

The servos and levers and whatnot don't seem to have extra play in them. I will fiddle with re-circ settings and vent shutoffs on the way home to see if that helps at all. Thanks for the page numbers! It makes searching that so much easier.

If that doesn't reveal anything, I will take off the plenum air intake and see what I can find. I've never taken it off, but it is cracked and seems to be missing a cap for a hole in the center (not the bolt hole). Who knows what's in there...

 

Messing with the re-circ didn't stop the noise and there didn't appear to be anything in the intake that could be moving around. I got a pretty good look in there and felt around.

I'm kinda stumped. My next move is to have someone else drive it while I put my head down there and try to find the source. If anyone knows of a better plan, let me know.

 

Which side does it seem to be coming from? Can you tell?

PS- Love the user name, but where's the link to your "law blog"?

 

I just posted this same thing the other day. My chirp comes from the pasenger side. It is not under the car. It can happen when idle but usually only makes noise while excelerating with AC on. If i have AC on and im COASTING 5 - 45 mph its NOT there. If i step on the gas at any point from 0-45 ish with AC on the chirp is there. It goes away after 45. Sometimes its gone after using the car for a while. Its the strangest thing. Its not that loud but just a funny quirk im trying to figure out.

 

It's from the passenger side.

Haha my law blog is down at the moment but it will be back up so I can drop some law bombs

While we may have similar problems, my chirp doesn't have any correlation to the gas pedal and my blower fan is completely removed, so the AC setting doesn't have any effect either. And my noise only starts at 45...

But anyway, if I figure out what's going on I will be sure to let you know the cause.

 

I've had dashes that squeak when they vibrate at just the right frequency. Those are hard to find. When found, a piece of rubber wedged into the offending area will usually stop it.

symaxwell - My Fan squeak only happened on left turns and only when it was the correct temperature and the fan was ON. Turning applied pressure in the correct direction for the squeal to happen. I'm guessing accelerating is causing the pressure for yours. If the fan was off, NO squeak. Next time yours squeaks, turn off the fan. If it immediately stops, you KNOW it's the fan.

 

symmaxwell - I can't say for sure that my problem is fixed, but it has been gone for a couple days now. In my search for the noise, I removed the A-pillar trim and tightened down the plenum air intake (black cowling at the bottom of the windshield). Mine was cracked in the middle and one of the rubber grommets for a screw had backed itself out. I'm about to drive for a few hours today so I think I will know definitively by tonight whether it's fixed or not. I'll keep you posted.