Please post your a/c performance
Thread Starter
Junior Member
Joined: Oct 2012
Posts: 57
Likes: 8
From: SRQ, FL
2001 S430 W220
Please post your a/c performance
I am trying to figure out if I am getting 'decent' or expected a/c performance in this hot as hell weather in my 01 S430. Sometimes I cannot figure out if that's just the way it is, or if there's a problem.
At about 100F outdoor with 30-40 percent humidity, when IDLING for 10 minutes, vent temps are around 60F. That's a -40F difference, which most a/c documentation says is adequate. When DRIVING, I am getting 50-55F at the vents which starts to feel good. 60F does not really feel cool to me. These values are after replacing the receiver drier and recharging the system to proper 34oz R134a spec. I also changed cabin filters. My 2015 Audi A5 gets to 40F vent temps with ease although we may not be comparing apples to apples here.
Would you think this does not cool enough? Should I look at replacing expansion valve or condenser to get better results?
At about 100F outdoor with 30-40 percent humidity, when IDLING for 10 minutes, vent temps are around 60F. That's a -40F difference, which most a/c documentation says is adequate. When DRIVING, I am getting 50-55F at the vents which starts to feel good. 60F does not really feel cool to me. These values are after replacing the receiver drier and recharging the system to proper 34oz R134a spec. I also changed cabin filters. My 2015 Audi A5 gets to 40F vent temps with ease although we may not be comparing apples to apples here.
Would you think this does not cool enough? Should I look at replacing expansion valve or condenser to get better results?
Last edited by DimcheSRQ; Aug 9, 2023 at 07:42 PM.
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Mercedes
I am trying to figure out if I am getting 'decent' or expected a/c performance in this hot as well weather in my 01 S430. Sometimes I cannot figure out if that's just the way it is, or if there's a problem.
At about 100F outdoor with 30-40 percent humidity, when IDLING for 10 minutes, vent temps are around 60F. That's a -40F difference, which most a/c documentation says is adequate. When DRIVING, I am getting 50-55F at the vents which starts to feel good. 60F does not really feel cool to me. These values are after replacing the receiver drier and recharging the system to proper 34oz R134a spec. I also changed cabin filters. My 2015 Audi A5 gets to 40F vent temps with ease although we may not be comparing apples to apples here.
Would you think this does not cool enough? Should I look at replacing expansion valve or condenser to get better results?
At about 100F outdoor with 30-40 percent humidity, when IDLING for 10 minutes, vent temps are around 60F. That's a -40F difference, which most a/c documentation says is adequate. When DRIVING, I am getting 50-55F at the vents which starts to feel good. 60F does not really feel cool to me. These values are after replacing the receiver drier and recharging the system to proper 34oz R134a spec. I also changed cabin filters. My 2015 Audi A5 gets to 40F vent temps with ease although we may not be comparing apples to apples here.
Would you think this does not cool enough? Should I look at replacing expansion valve or condenser to get better results?
Junior Member
Joined: Nov 2021
Posts: 18
Likes: 9
From: Houston
01 S430 Sport---- 23 S580 Sport
My AC on my 2001 S430 performs the same exact way. I honestly thought something was wrong with the compressor (2 years old), but apparently this is normal (?) behavior. In the morning and at night it blows ice cold though, so I suppose this is just the AC trying to overwork in the heat and when idling in traffic or at lights, the ambient air is being cooled enough when sucked by the fan. I guess the 105 degree weather and high humidity here in Houston doesn't help.
Thread Starter
Junior Member
Joined: Oct 2012
Posts: 57
Likes: 8
From: SRQ, FL
2001 S430 W220
It's blowing pretty strong. No problems there. I was thinking to do an evaporator flush with special foaming cleaner up through the condensation drain line underneath. Maybe after 23 years that thing has gunked up a bit.
Thread Starter
Junior Member
Joined: Oct 2012
Posts: 57
Likes: 8
From: SRQ, FL
2001 S430 W220
Thanks. I'll pass on 134a alternates, I believe that they are no different than 134a performance. I tried Duracool a while back, and it actually got worse. They tend to be more flammable and a lot more expensive than a 12 oz 134 can at walmart.
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MBWorld Fanatic!
Joined: Sep 2018
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From: New Orleans Area
2015 E400 Sedan
cleaning coils is always good inside and out..
but think what is diffrent with AC performance:
One you sitting still
other you are moving..
so what is different is Compressor RPM and air flow across the condenser.
I think your AC may have the variable compressor and if it does maybe the control cartridge valve is going out and not changing comp. displacement larger with low speeds??
Or like I said early fan air flow is low due to fan or clogged coils??
Or crappy MB ac system design.
but think what is diffrent with AC performance:
One you sitting still
other you are moving..
so what is different is Compressor RPM and air flow across the condenser.
I think your AC may have the variable compressor and if it does maybe the control cartridge valve is going out and not changing comp. displacement larger with low speeds??
Or like I said early fan air flow is low due to fan or clogged coils??
Or crappy MB ac system design.
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From: Netherlands
CL 600 '00 5.8L V12
Refill your AC system with a UV die and check, with an UV light, if there are any spots on your condensor or any other place.
