wierd sound coming from dash board when heat is on [Archive] - Bimmerfest - BMW Forums

: wierd sound coming from dash board when heat is on

01-24-2012, 08:12 AM
So as i was driving today i noticed a crazy sound coming from my dash.

It sounds like a bottle of water is rattling side to side and water is splashing all over. Its coming from my driver side vents only when heat is on. When it does not blow hot air the noise disappears but as soon as i raise the heat over 78 degrees the sound returns.

Its such a weird noise. It happens mostly when i set vent to blow heat to feet only.

Does anyone know what im talking about.

This sound is really only noticed when the car is at a stop and radio is off, heat work fine, all vents blow air. It just sounds like something inside the vents is struggling to open and close. I dont want to have the dealer start taking everything apart on a new car to find this problem but its so crazy.

01-24-2012, 02:33 PM
It's a shot in the dark, but what do you think about air bubbles in the coolant system or heater core?

02-09-2012, 04:43 PM
I noticed it too. But i think it's some sort of electrical sensor that constantly checks. I had that on 3 prior bmws as well. All diff but it's all related to vent. Very low buzz sound with periodic timing.