I have a 1997 C280. The air conditioning whistles (an up and down whistle). It doesn't matter which fan speed I have it set to. It's a very distracting and annoying sound. I recently replaced the cabin filter about a month ago, but this noise just started. I took out the cabin filter and put it back in, but this had no effect. Could the unit be low on freon? What should the pressure read on the low side?
Any help is GREATLY appreciated.

Hi,

Did you do a search? I seem to remember something about that before, a years or so ago.

Mike

__________________
1998 C230 330,000 miles (currently dead of second failed EIS, yours will fail too, turning you into the dealer's personal human cash machine)
1988 F150 144,000 miles (leaks all the colors of the rainbow)
Previous stars: 1981 Brava 210,000 miles, 1978 128 150,000 miles, 1977 B200 Van 175,000 miles, 1972 Vega (great, if rusty, car), 1972 Celica, 1986.5 Supra

Thanks for respondig. I haven't had any luck searching. The question is out there but no answers.

Hi,

In this thread it was a vacuum leak at an actuator and the whistle changed with engine speed: Whistling HVAC System?

In this thread they are suggesting it is the motor/regulator:
a/c problem in C230K

Mike

__________________
1998 C230 330,000 miles (currently dead of second failed EIS, yours will fail too, turning you into the dealer's personal human cash machine)
1988 F150 144,000 miles (leaks all the colors of the rainbow)
Previous stars: 1981 Brava 210,000 miles, 1978 128 150,000 miles, 1977 B200 Van 175,000 miles, 1972 Vega (great, if rusty, car), 1972 Celica, 1986.5 Supra

This is dumb I know but I had a whistle also and it was the passenger side dash vent being almost closed. Opened it up and the whistle was gone. Hope yours' is that simple.

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95 SL500 Smoke Silver, Parchment 64K
07 E350 4matic Station Wagon White 34K
02 E320 4Matic Silver/grey 80K
05 F150 Silver 44K

I have the same sound in my E320 I think it's something with the vents acutators but I think it*s no nice job to fix that so I leave it for now if it's get worse I have to look in to it there is not so often it will whistle so I can take it for now.
I don't think the cabin filter is the problem why should the noice only occur in AC mode then?

Mike,
Thanks again for your responses. Do you have an image of where the actuators and vacuum lines are located?

Sorry I don't have anything. But those threads I referenced gave decent explanations I think. Maybe someone else can provide a picture for you.

Mike

__________________
1998 C230 330,000 miles (currently dead of second failed EIS, yours will fail too, turning you into the dealer's personal human cash machine)
1988 F150 144,000 miles (leaks all the colors of the rainbow)
Previous stars: 1981 Brava 210,000 miles, 1978 128 150,000 miles, 1977 B200 Van 175,000 miles, 1972 Vega (great, if rusty, car), 1972 Celica, 1986.5 Supra

That thread regarding the actuator pod was mine - I have pics and will try to dig them up. They were NOT easy to get to; I assume the dash would normally have to be removed to access them.

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08 W251 R350
97 W210 E320
91 W124 300E
86 W126 560SEL
85 W126 380SE Silver
85 W126 380SE Cranberry
79 W123 250
78 W123 280E
75 W114 280

Keep in mind you were working on a W210 and he has a W202 so they might be different. I have no idea.

Mike

__________________
1998 C230 330,000 miles (currently dead of second failed EIS, yours will fail too, turning you into the dealer's personal human cash machine)
1988 F150 144,000 miles (leaks all the colors of the rainbow)
Previous stars: 1981 Brava 210,000 miles, 1978 128 150,000 miles, 1977 B200 Van 175,000 miles, 1972 Vega (great, if rusty, car), 1972 Celica, 1986.5 Supra