W202 air conditioner
 

W202 1998 C230: In very hot weather (>95 F), the a/c compressor cycles on and off at idle, and does not maintain cold air. This typically occurs when sitting in traffic.

The compressor, dryer bottle, a/c switch/sensor, and associated a/c rings have been replaced. Any suggestions?

If your car has AUX cooling fans, I would check those. I would not recommend replacing any mechanical components before the electrical systems have been checked out.

In general, in a W124, AC compressor is usually turned on and off every 20 secs if the engine is overheating and to prevent AC components from freezing.

There are numerous senors in the AC system which can also cause a problem, but the AUX fans seem like the most likely cause.

Does the engine overheat while the car is stopped?

No, the engine does not overheat at all. The auxillary fan can be heard prominently (car sounds like a jet as it comes down the road). I cannot imagine that this is normal.

This thread may help you diagnose the problem. On mine, this was caused by a faulty evaporator temp sensor.

Thank you for the thread. Great pics of C & E class! :)

Yes - "short cycling" describes the problem. The refrigerant system was evacuated and recharged, but perhaps there is a leak. Is this possible? What would cause the leak? What would be the possible location(s) of such leak? Why would it only occur in very hot weather, when the engine is hot?

:rolleyes:

Thank you for the information.

What you describe is called "short cycling" and is an indication of a low refrigerant charge.

Hope this helps,