AC Issue 2005 ML350 3.5L W163
Thread Starter
Junior Member
Joined: Nov 2008
Posts: 31
Likes: 2
From: Lathrop, Ca
2005 ML350 Sport
AC Issue 2005 ML350 3.5L W163
This issue is unique in that it only happens when the engine is started for the first time after setting all night or for any 24-hour period.
1. Start the engine and let idle dropdown.
2. Then turn AC on Auto 64 degrees. Air coming out the dash vents will be ambient air temperature for the next 5-10 min.
3. So if it is in the middle of the afternoon and the outside temperature is 105deg that's what blows out for 5-10 min then it switches to cold.
4. After that, stopping and starting the engine everything is fine.
5. The next day same process.
6. I've had pressures checked and Freon removed and refilled all is good and no leaks. Have a friend who owns a Radiator/AC shop since 1978. Have not taken into Mercedes Benz yet.
7. Possible cause the Heater/AC blend door sticks on the heater side but slowly move to the AC side.
This issue started last summer like a light switch was turned on.
Any information and help are appreciated.
1. Start the engine and let idle dropdown.
2. Then turn AC on Auto 64 degrees. Air coming out the dash vents will be ambient air temperature for the next 5-10 min.
3. So if it is in the middle of the afternoon and the outside temperature is 105deg that's what blows out for 5-10 min then it switches to cold.
4. After that, stopping and starting the engine everything is fine.
5. The next day same process.
6. I've had pressures checked and Freon removed and refilled all is good and no leaks. Have a friend who owns a Radiator/AC shop since 1978. Have not taken into Mercedes Benz yet.
7. Possible cause the Heater/AC blend door sticks on the heater side but slowly move to the AC side.
This issue started last summer like a light switch was turned on.
Any information and help are appreciated.
Last edited by 1stChendeng; Jun 2, 2022 at 01:22 AM.
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Joined: Sep 2013
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2021 GLB250 FWD, 2023 GLA250 FWD, 2013 C250, 2015 GLK350, 2005 ML350SE, 2003 E320
Good luck with this. It gets worse. Maybe Maj Dundee can help diagnose. Indie shop and Mercedes dealer said our 2005 ML350 SE was “performing as designed.” When other things started to fail around 200k miles we traded it in on a new one.
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Joined: Oct 2011
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From: Bronx, N.Y.
2002 ML 320 & 2006 ML500
Yes, but only when the codes will tell.
