Skip the auto shop - Our mechanics make house calls

Q: A/C cooling fan only starts working at 93 degrees

asked by on

The cooling fan in A/C doesn’t start to work until the temperature reaches about 93 degrees. That doesn’t seem normal to me. I didn’t find any water leakages, but the coolant box is still decreasing water. Another problem is when I park the car, after driving around in town, the water waste pipe throws out water. But on the interstate highway, it works fine. What is causing these problem?

There doesn’t seem to be past information on the A/C not turning on until 93 degrees for a 2011 Mercedes Benz S550. I would try to see if the automatic temperature control is set to automatic and dial temperature to 65 degrees. The blower and A/C should come on high blower speeds and get cool quick. If not, then you may have a problem with ambient temperature sensor. The coolant leak may be due to the radiator cap not holding the correct pressure or overfilling the coolant reservoir. Your best bet may be to have a trained mechanic inspect the AC system in person and recommend the appropriate repairs.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. A/C cooling fan only starts working at 93 degrees

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Squealing noise, runs bumpy over 50 mph - 2005 Mercedes-Benz ML500

Hi! A good place to begin is with a thorough visual inspection performed on your Mercedes. Squealing sounds under the hood frequently come from accessory belts. This can be due to age or a worn tensioner. That's one of those...

Q: Driver's seat not moving

The "thing under the seat" could be the seat frame, or power motor assembly. The lower power seat is a separate part from the seat itself and may need to be replaced. The power seat frame is not a serviceable...

Q: Engine drag w/ a.c on

The a/c system has an idle up function and that should be checked. If the idle up function is not working properly, when you turn on the a/c the engine will bog down. You are also describing overall poor engine...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...