jenskleis

Hi guys,

My ventilation system has started whistling. And it's driving me up the wall!

The whistle starts, when I drive 100 km/h or above and it continues regardless of whether I send the air through the central and side vents and/or the windscreen vents and/or towards the foot-well.

If I turn the ventilation fan speed **** to "0" the whistle stops. However, it persists unchanged when the fan speed is at 1, 2, 3 or 4. As long as I drive 100 km/h or above, it's there.

It sounds as if air is being forced through a small hole or crack and I therefore suspect a leak in the ducts, which channel fresh air into the ventilation system via the outside air intake below the windscreen wipers.

Or perhaps one of the air duct servos is only partly closed.

Any ideas?

Take care,

Jens

Railmaster.

Could be a bearing in one of the fans in the frunk.

ECU Doctors

What Railmaster said.

Also, the Fresh Air Flap is playing a part when you set the CCU to "0" as it closes and doesn't let air into the cabin.

When you set the Fan Speed **** to "1" and above, this Flap opens letting air into the cabin.

Also test enabling the "Recirculation" and disabling it. See if that causes any changes.

jenskleis

Many thanks for the replies!

I will give your suggestions a try and will keep you posted.

Take care,

Jens

ToreB

Hi Jens!
Whistling and whining in the ventilation system is most often caused by a inert (non-operational) resirculation flap actuator. The resirc flap is vacuum operated, and most often the vacuum hose has been pulled out of the rubber bend of the actuator under the dashboard or on the electric valve in the frunk. See this thread for pictures.

Wheezing may also be caused by a defective ventilation servo, possibly the fresh air servo or one or both mixer servos. My DIY page contains a quick method of testing these servos, as well as the resirc flap.

Cheers,
Tore

jenskleis

Hi Tore,

Thanks a lot for your input. I will read your DYI pages and will follow your advice.

BTW, the LED bulbs arrived and they are working perfectly. Fabulous products!

Take care,

Jens

jenskleis

So, I took the car out today and tried to turn the recirculation on and off a few times. Judging from the brief interruption in air flow, when I activated it, I suppose it is working.

After activating the recirc, the whistle seems to have disappeared. I guess the recirc flap was not entirely closed before, thus allowing air to create the whistle.

Many thanks for the suggestions all. You no doubt saved me a lot of time rummaging around the innards of my ventilation system.

Take care,

Jens

ECU Doctors

Congrants Jen!