irondad

In the last few weeks since it's gotten warm I've noticed that when I first start the car, warm (or not cooled) air comes out of the vents even though "auto" is pushed and it's on the lowest temperature setting. Within a couple of minutes the air gets cold and then works perfectly and I usually have to make it less cold.

So, in short: something isn't switching or turning on or kicking in, and once it does the A/C works perfectly. Warm, then cold and stays cold.

I've searched and Googled and seen lots of "cold then warm" scenarios, or "warm then cold then warm" or "cold then warm then cold", but no "warm then cold" like mine. I know nothing about air conditioners and live in hot Texas so desperately need your help!

Plutoe

Regrettably with the advent of the W211 drivers no longer have access to the fault and actual value tests which W210 drivers have and use to help solve a problem like yours-----all the billy bob AC guys will say I can fix that---sure--- so do not get suckered in. At best all they can do is place a set of gauges on the system and determine the amount of refrigerant and the status of the expansion valve---they can not access all the sensors, flaps and all the other stuff.

That said the bad news is that your AC system can only be CORRECTLY diagnosed with DAS Xentry or equal

irondad

What is a DAS Xentry, and that allows them to access all the sensors, flaps and all the other stuff? Is that dealer only?

Plutoe

DAS Xentry is the name of the MB first line diagnostic software---used worldwide to diagnose their products, however like most software is available through various channels and used by poor schmucks like me to diagnose MB products.

You objective is to find another schmuck like me in your area!! If not then the alternative is Ms Daimler!!

PS:do you live anywhere near Tampa

pragmatic1

My e55 is having a similar problem. I'm guessing it's related to faulty change-over valve. As Plutoe suggested; diagnostic software seems like a good option. This link may help as well ~ https://mbworld.org/forums/e-class-w...rol-valve.html

Plutoe

I can appreciate post #5 contribution, however the key word is "guessing". That approach is expensive and time consuming----Why guess and do the job more than once---find the problem, then fix the problem once---let others spend money on speculation!!

E55Greasemonkey

You'll need to have it properly diagnosed by a competent MB shop or dealer...That being said, I recently fixed a 211 with a similar problem, and it turned out the compressor was at fault. However, there are many other things that can cause the same symptom.

Barry45RPM

Occaisionally when I start the car mine will also blow Hot then suddenly change to cold. (Since new in the Summer of 2007) Its not the heat build-up of the ducts when parked... you're right something in the system is confused on start-up & then catches on & cools. Its not often but it is noticeable when it happens. I just press MAX cool to smack it up side the head when this happens... or just wait the few seconds it takes to wake up and blow cold..

Its an MB... overwrought and overthought.

vettdvr

Anyone run a high side low side pressure check?