BlackjackM

So I've had my C300 for about 5 days now, and I absolutely love it. The combination of the sporty exterior styling with typical Mercedes-Benz luxury inside is the perfect combo for me. One attribute though that I don't like:

My wife and I went on a trip this past holiday weekend, and it was very hot out. We had the climate control set to 72 degrees on Auto, but the fan seemed like it would constantly run at a high speed even though it was comfortable inside the cabin. I tried turning the dial to the next temp higher, but all it did was blow warmer air at the same high speed. I don't know where the sensor is positoned but if it's in the sun, perhaps it's not reading correctly. Further, I've read on here that people have had trouble with a musty smelling climate system and it's been suggested that it's because people aren't using Auto mode.

Does anyone else feel that the fan programming is too aggressive? In past cars, I've just had to "set it and forget it". I'm hoping that the unusually hot weather had something to do with it.

TRauppius

I have a 2009 C350W operating in the Philadelphia region where it gets fairly hot and muggy in the summer, and I have also done a trip down to southern Florida in July. My experience is that the AUTO mode and setting the temperature at 74F gives me a very comfortable ride with moderate fan levels. Sometimes, when the the car is VERY HOT at startup, I use the MAX setting for about 10 minutes to cool things down, albeit at higher fan speed and noise. Thereafter just deselect MAX and the auto takes over.

Maybe you have a problem with one or more of the radiant heat or humidity sensors. If this issues persists I think you should take it to the dealer for a warranty service check of this system.

MURTAZAC350

Honestly, i wouldnt put too much thought on this. Having had mine since 2009, looking back, if i had taken my car to the dealers for stuff like this, then i'd pretty much have an office at the dealers

There are so many things which will pop up in the next few year. Dont get me wrong, I love my C350, but sometimes just sometimes i wish i had a honda

MURTAZAC350

Oh yea, one more thing, the most frequent answer i hear from the service people ' We didnt find anything wrong, everythngs like it should be '

And yea most of the time the thing is not reproducible at the dealers but then i dont want to leave my car there overnight.

BlackjackM

Thanks for the feedback. I will try it out on 74 and see how it works. In the past it seemed that it would just blow out warmer air at the high setting but I will give it more time next time to see what happens.

jctevere

It was probably due to the extreme heat. My car used to do the same thing, to combat the solar heat fromt he sun. After I got my tints I noticed my A/C doesn't work as hard when I have it on Auto.

joshg1001

On all the cars I have owned, I have never used the auto function, because to me, its just always HIGH. Maybe it is because I live in SF where we dont get a lot of hot weather, but on the off day that we do, I just turn the fan speed on low or whatever, and the temp at 68. I dont do the set it and forget it. When it gets too cold, I turn the AC compressor off, and when its still too hot, I just turn the fan speed up one notch. lol

As for the musty smell, there are only two ways of preventing/combatting this. The first is to always have the aircon on, that is on auto all the time. For those who dont use auto like me, the best way is to turn off the air compressor but keep the fan on so that the moisture in the vent can evaporate fully, thereby not giving it a chance to start molding.

BenTrovato

Auto has it's uses.. on extreme hot days where the UV index is extra hot, the sensor may not be accurate. The sensor will be most accurate at night or when it's cloudy. If during those conditions you experience problems, then just ask them to take a look at it the next time you're in for service.

I've noticed similar issues but only on very sunny humid days. I'm sure there are other conditions where the sensor is not accurate, but this all I've cared to pay attention to so far lol.

Peabody

I'll also say that if you think the fan is running too hard, press the max button and let it run for a minute, and then press the auto button again. It should be at a very low setting after that.

na011

The answer to the AC smell:

http://www.benzworld.org/forums/w204...0-ac-odor.html

Sportstick

Interesting coincidence, as I was just exploring the same concern on our 2008 E Class after noting how well the 09 C Class works. The AUTO function in my C is a true "set and forget" system, unless a brutal day requires MAX COOL. It reaches the desired temp, and calms down and holds comfort better than most cars I can remember. The E, however, always sounds like we're on the edge of a hurricane (yes, all the vents are open), although it also maintains a comfortable environment. We always leave both cars on AUTO (although sometimes manually reduce the E fan speed), and have no odor problems with either car.