2000 W210 E320 whistle from fresh-air setting
 

Our 2000 E320 has developed a whistle noise from the vents that varies with the fan blower speed. By selecting recirculation the noise is completely gone.

I'm guessing that the blend door isn't resting where it should when it's set to allow fresh air in.

I check the filters. Removing them made the noise louder - I believe because of the increased air flow.

Any ideas?

-Tad

The 210 whistles when the outer dash vents are partially closed. Check the open/close knobs on the dash. Yes, it's a longshot, but always start with the easy stuff! :)

Thanks. I checked that too. It whistles all the time that it's set to allow fresh-air in.

-Tad

It's the blower itself. Mine does it too. I have ignored it.
Steve

That's disappointing. I guess I'll have to take it apart and look for something in the fan making it whistle. Hopefully it is within reach.

-Tad

I've heard the blowers screech, but never whistle. How long since the cabin air filters were changed?

They were done 20k miles ago, but I removed them both (both are charcoal, is that correct) and the noise got louder.

-Tad

Also have an slight intermittant whistling noise coming from the vents. I think mine is only when the A/C is on. Also choose to ignore for the last 6 years.:rolleyes:

The cabin filters should be white paper type material, located behind the glove box. It sounds like you may have taken out the charcoal filters which are accessed from under the dash. You may have something interfering with the fresh air flap.

good luck, Robert