2009 E550 has melting plastic smell from heater vents
I have a 2009 E550 with about 98000 miles, have owned it about a year.
There is an odor that comes from the cabin heating/ventilation system that I first noticed several months ago. I took it to MB Service at the dealership where I bought the car a few times but I finally gave up on them as they seemed to be just guessing at the issue and generally giving me the run-around.
The odor comes from the heater vents, and smells like plastic that is hot but not burning; there is no smoke. If I put the blower to full speed the odor will soon dissipate, or become diluted sufficiently. If I set the fan speed back to a lower setting the odor will come back.
There are no oil leaks from the engine and I see no obvious sources of the smell in the engine compartment. At first I thought the smell was like hot oil, but it is actually more like hot melted paraffin wax, or melted plastic.
Does anyone have any ideas?
Thanks,
Steve



