Scionti95

After parking out in the sun and heat, (Tampa, Fl.), after starting the car, the air volume coming out of the vents in the A/C mode (temp. set at 78 degrees) came on at the highest level. Understandable as it was quite hot inside the car.My wife standing outside the car near the front was completely surprised by the fan noise emitting from beneath the hood. As long as the climate control was in the "Auto" mode, the speed of the fan would not decrease. I thought it would decrease as I drove, but after close to 15 miles of driving, there was no decrease in the volume of air coming out of the vents. Could not hear the radio from the loud blowing noise. Had to use the rocker switch to manually control the speed. Started to experiment as I drove by raising the temperature and still no decrease of air blowing from vents. Same event also occurred today. This only occurs when car is parked in the sun/heat. It is garaged at night, so normal operation of fan speed blowing in the AM is normal. Did not experience this during the winter months, but the heat is coming on now in Florida. Any ideas/suggestions before I take the car into the dealer would be greatly appreciated. It is a 2010 E-350, so any issue will be covered by warranty, but would like to have some knowledge before showing up at the dealership. Thank you

Wig

Maybe after 15 mins the air con has not yet cooled the car to 78 degrees, so it continues at max fan speed?

Scionti95

Wig: Thank You for your prompt reply. It is appreciated. I had strongly considered your suggestion, but thought with the outside temperature only 82 degrees, it would reach the inside temperature of 78 degrees quickly. Perhaps my assumption was incorrect. Hopefully others will jump on this thread and provide their thoughts/opinions.
Again, thank You Wig for your prompt reply. I am in the learning stage with this car and appreciate all input.
Semper fi

Tjdehya

If the outside temp is 82f and its sunny if your windows are not tinted then the temp inside the car will always be above outside temp.
Sometimes it's just easier to drive with the windows open for a minute or two so that all the hot air leaves the car.

oorah

Scionti95

Tjdehya:Thank you for post. Good info and beginning to make sense. Windows are not tinted and I had the cover slid back allowing light/sun to enter through the abbreviated glass roof. Am beginning to believe that perhaps I do not have an "Auto" problem on the climate control, but rather simply the heat is cranking up in Florida and will manually adjust air flow with the rocker switches. Greatly appreciate your take on my concern Tjdehya. Anyone else out their that has an opinion, jump in.

Semper fi !!

Sathinas

May want to check the climate control sensor fan. I don't know if yours has one, but all of the MB's I've seen have a little fan in front or behind the sensor that pulls cabin air over the temperature sensor in order to calculate cabin temperature.

The fan blades tend to get crud on them and lose their ability to pull air, or the motors simply fail.

Scionti95

Sathinas: Did not have knowledge of a small fan located near the sensor that pulls/pushes cabin air over the temperature sensor in order to calculate cabin temperature. I am going to rule out the crud on the blades as the car is only a little over 7 months old, but the failed motor is a distinct possibility to review/examine.

Thank you for your input and suggested problem area.

Semper fi !!

Pntblnk

I think you are on to something here. The sensor must still think that the internal temperature is still well above your set point. If your car has been sitting in the hot sun the heat set will be immense and take a while to normalize again. Internal temp in the afternoon sun can reach 120 or higher. That causes all of the materials inside the cabin to normalize at this same high temperature. My guess is that the sensor and surrounding materials are retaining the heat for a longer period of time than you are driving and haven't cooled to the same termperature as the cabin air.

My $0.02.

I'm no expert, but I did sleep at a Holiday Inn last night.

Scionti95

Pntblnk: Thank you for your post and validation of what may be occurring. Going into the dealership tomorrow AM and will post up what I find out.

Roof over your head, bed and a shower; beats the boonies any night.

Semper fi !!

El Cid

When this happens in my car in S.C., I just hit the fan button to lower fan speed. It changes the system to regular A/C. When car cools down, I hit the Auto button and it works normally.
Airborne!

ImInPA

This sounds like the normal operation of every automobile that I have owned for the past 20 years with Auto climate control. Now, if it never lowers the fan speed even after it has cooled down for a while, then there is a problem.

Scionti95

El Cid: Thanks for the post. Rainy overcast day in Tampa, so no repeat of problem I have been experiencing. Good tip as to how to handle in future if no fan problem found at dealership tomorrow.

Semper fi !!

Scionti95

ImInPA: Thanks for the post. Have driven the car for over 1/2 hour with temp. set at 78 degrees. No decrease in fan speed. Ratcheted it up to 80-81-82 degrees and still no slow down in fan speed. Sathinas suggested the climate control sensor fan as well as the temperature sensor. Those areas will be starting point when going to the dealership tomorrow.

Again, thanks for your experience and will post up tomorrow after visiting the dealership.

Semper fi !!

ttoE550

One thing I did not see mentioned: After running for 1/2 hr on full blast, the AC should make the car COLD. As a point of reference, my car is set to 68, and in the summer after sitting in the sun it might run on high for 10 minutes or so. If your car is not COLD, it might mean something is wrong with the AC.

Good luck tomorrow.

Scionti95

Took the car by the dealership yesterday and they were unable to find anything out of what is termed "normal". They felt that because the car is black with black interior, that is contributing to the high heat concentration inside the vehicle when parked in the sun, resulting in high fan speed when in "Auto" mode. Difficult to debate that point, so will continue to monitor situation under different variables. Appreciate all the input provided and will keep you updated.

Semper fi

ImInPA

Another thing that has not been mentioned. Do you have the MAX/AC button pushed? This will cause the fan to stay on high and overrides the AUTO setting.

Just a thought.

Tjdehya

I thought everyone in FL drove the car off the lot and directly to a tint shop to apply 5% Tints?
Are you planning on tinting your windows?

BenzE350

Your description of 1/2 hour at high fan speed does not sound normal in this situation. Do you have it set at Max/AC as someone else mentioned?

El Cid

I tend to leave my sunroof tilted open when I park the car in the sun. Assuming I feel secure about the area and no chance of rain (or pollen).
Another reason to leave tilted for newer cars is that it lets the "plastics" evaporation to escape. Happens in all cars as plastics, vinyl, etc. give off a gas for first few months. May build up on inside of windows.
BTW, What is the difference between a Sun Roof and a Moon Roof?

BenzE350

1. Depends on the time of day and/or how much you have been drinking or smoking.

2. From Answers.com