AC advice
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Junior Member
Joined: Oct 2008
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From: Kaiserslautern, Germany
09 Mars Red C350
AC advice
When I picked up my C350 in Sindelfingen i was advised to keep my AC on at all times and to just adjust the temperature to where i was comfortable. I was so excited to pick my car up
I didn't pay attention to the reason. Can anyone help me with this?
I didn't pay attention to the reason. Can anyone help me with this?
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From: Irvine, CA
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i havent heard this one before...
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i think it is to keep the car from getting that moldy smell that comes from the condensation produced by the AC unit in the vents.
By keeping the aircon on all the time, the water inside will either dry out (in warmer air) or stay in liquid form (in cold AC), which are not ideal conditions for the mold spores to grow.
You dont have to do this. What i do when i turn on the AC is made sure you turn off the AC but keep the air vent on to dry the water inside. Do this maybe 10 minutes before destination
By keeping the aircon on all the time, the water inside will either dry out (in warmer air) or stay in liquid form (in cold AC), which are not ideal conditions for the mold spores to grow.
You dont have to do this. What i do when i turn on the AC is made sure you turn off the AC but keep the air vent on to dry the water inside. Do this maybe 10 minutes before destination
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From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
There is a good technical reason. You should run your aircon at least weekly if you want decent compressor life even in the middle of winter. Keeps seals in good condition & pliable, circulates the lubricant & releases the refrigerant comingled in the lubricant. This is why Benz recommend it - The oil companies have been trying to get this into all car owners manuals for years. Of course the OEMs would rather sell more replacement compressors.
Agree with warming the system up prior to shutdown to prevent bacterial growth & smells
Agree with warming the system up prior to shutdown to prevent bacterial growth & smells
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I think the advice was "old school knowledge", the current compressors run continuously and switching AC on or off doesn't have any effect on compressor seals' life.
The compressor works with a variable power from minimum 2% to max 100%.
The mould issue comes from water condensation at the heater core bottom as mentioned. There is nothing that keeps fresh water coming when the car is parked. Keeping the AC on all the time cannot improve things against mould. The advice to dry the heater core just before parking the car is the best approach but unfortunately asks some discipline from the driver, at least myself I would often forget to do that.
The compressor works with a variable power from minimum 2% to max 100%.
The mould issue comes from water condensation at the heater core bottom as mentioned. There is nothing that keeps fresh water coming when the car is parked. Keeping the AC on all the time cannot improve things against mould. The advice to dry the heater core just before parking the car is the best approach but unfortunately asks some discipline from the driver, at least myself I would often forget to do that.
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There is nothing that keeps fresh water coming when the car is parked.
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From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
I am well aware the compressors run full time - They need to be made to do some work & cycle the refrigerant. Testing has proven that this extends life. I know where you are coming from though - It's less of an issue than it used to be with a clutched compressor that remained stationary when off.
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From: UK
2021 C63S coupe
There is a good technical reason. You should run your aircon at least weekly if you want decent compressor life even in the middle of winter. Keeps seals in good condition & pliable, circulates the lubricant & releases the refrigerant comingled in the lubricant. This is why Benz recommend it - The oil companies have been trying to get this into all car owners manuals for years. Of course the OEMs would rather sell more replacement compressors.
Agree with warming the system up prior to shutdown to prevent bacterial growth & smells
Agree with warming the system up prior to shutdown to prevent bacterial growth & smells
The lady who did my handover at Sindelfingen did say the same, keep it on always, however I don't but make sure I use it at least once a week.
My car developed an electrical fault which damaged the battery, when MB Assistance arrived and removed the aircon filter above the battery, I noticed that when the car is switched of, the vent moves into the open position to allow air to circulate while the car is not in use, this I suppose is desinged to help with the 'foul smell' we talk about.
Last edited by Uga Uga; Jul 7, 2009 at 01:29 PM.
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From: SEATTLE WASHINGTON USA
'08 C300 Lux Barolo Red Beige Leather P2 MM 18" wheels '84 944
Swash plates
I don't know when they were phased in but even my '01 C320 used one. Which is why you never feel the compressor kick in because the plates change angle slowly. Eliminating the clutch removes one more trouble item.
I run my AC constantly.
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From: SEATTLE WASHINGTON USA
'08 C300 Lux Barolo Red Beige Leather P2 MM 18" wheels '84 944
Filter
Very very true, my next door neighbour never used his aircon, (Jaguar) last week when his wife switched it on the whole thing exploded, gas, fluids etc... The technician said lack of frequent use damaged the seals.
The lady who did my handover at Sindelfingen did say the same, keep it on always, however I don't but make sure I use it at least once a week.
My car developed an electrical fault which damaged the battery, when MB Assistance arrived and removed the aircon filter above the battery, I noticed that when the car is switched of, the vent moves into the open position to allow air to circulate while the car is not in use, this I suppose is designed to help with 'foul smell' we talk about.
The lady who did my handover at Sindelfingen did say the same, keep it on always, however I don't but make sure I use it at least once a week.
My car developed an electrical fault which damaged the battery, when MB Assistance arrived and removed the aircon filter above the battery, I noticed that when the car is switched of, the vent moves into the open position to allow air to circulate while the car is not in use, this I suppose is designed to help with 'foul smell' we talk about.
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From: Toronto, ON
2011 E350 4Matic Wagon, 2013 C350 4Matic Sedan
My car developed an electrical fault which damaged the battery, when MB Assistance arrived and removed the aircon filter above the battery, I noticed that when the car is switched of, the vent moves into the open position to allow air to circulate while the car is not in use, this I suppose is desinged to help with 'foul smell' we talk about.
DIY: Heater Blower Intake / Battery
As RLE mentioned the air filter is accessed from the passenger side footwell:
Cabin filter change
Has anyone actually experimented to see what kind of "hit" keeping the A/C running will take on the car? I personally found it to be negligible.
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From: Toronto
2009 C300 4Matic
awkward... i was told when i take the car off, to always remember to take off the fan/ac. so that when i start the car again they do no start up right away. :\
something about helping longevity of the ac system.
something about helping longevity of the ac system.
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From: UK
2021 C63S coupe
What I am referring to is the the air intake and not the filter, this can be found upon removal of the water trap.
Super Member
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From: UK
2021 C63S coupe
You were referring to this box:
DIY: Heater Blower Intake / Battery
As RLE mentioned the air filter is accessed from the passenger side footwell:
Cabin filter change
Has anyone actually experimented to see what kind of "hit" keeping the A/C running will take on the car? I personally found it to be negligible.
DIY: Heater Blower Intake / Battery
As RLE mentioned the air filter is accessed from the passenger side footwell:
Cabin filter change
Has anyone actually experimented to see what kind of "hit" keeping the A/C running will take on the car? I personally found it to be negligible.
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From: SEATTLE WASHINGTON USA
'08 C300 Lux Barolo Red Beige Leather P2 MM 18" wheels '84 944
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From: UK
2021 C63S coupe
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From: New Jersey
C 350 Obsidian Black
The Air Recirc / Fresh air valve on the 204 also works based off of speed. It will slowly close of outside / fresh air as the car speeds up. This helps to remove outside wind noise that normally comes through.
As far as running with or without the AC. I typically have it off, but certainly run it periodically to circulate they system and keep seals in good condition. I have not had any issues, but maybe garage parking also helps with keeping any moisture issues down.
As far as running with or without the AC. I typically have it off, but certainly run it periodically to circulate they system and keep seals in good condition. I have not had any issues, but maybe garage parking also helps with keeping any moisture issues down.
