A/C starts warm, then cools perfectly... any thoughts as to cause/solution?
Thread Starter
Super Member
Joined: Aug 2011
Posts: 504
Likes: 49
W205, X253, C190, W213,
A/C starts warm, then cools perfectly... any thoughts as to cause/solution?
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!
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!
Last edited by irondad; Jun 14, 2013 at 01:10 AM.
Thread Starter
Super Member
Joined: Aug 2011
Posts: 504
Likes: 49
W205, X253, C190, W213,
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
That said the bad news is that your AC system can only be CORRECTLY diagnosed with DAS Xentry or equal
Junior Member
Joined: Apr 2013
Posts: 39
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From: Southeast Texas
e 55
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
MBWorld Fanatic!
Joined: Jul 2012
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From: Orbiting the planet
This place is a joke.
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.
MBWorld Fanatic!
Joined: Mar 2004
Posts: 5,017
Likes: 16
From: Ft. Lauderdale Area, USA
2015 ML 350
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.
Its an MB... overwrought and overthought.
Last edited by Barry45RPM; Jun 18, 2013 at 12:51 PM.
