another E63 n00b observation/question - AC related
09-03-2009, 08:57 PM
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'09 E63 AMG sedan (sold); E36 M3, E90 M3
another E63 n00b observation/question - AC related
I've noticed a few times when I first start the car and drive off (car is started with the AC button OFF), the air immediately blows quite cold, definitely colder than outside, making me think the compressor MUST be on, despite the light indicating it is off. In this scenario, I had the temp selector set to LO.
In any other car I have owned, when you say "Off AC," then the coldest the air coming in the vents can ever be (no matter where you have the temp set at) is as cool as ambient air.
Made me wonder if my compressor was stuck ON or something. So I called service adviser, who did some research and indicated that the AC logic is "variable displacement" (or something like that) and that it never really shuts off, but responds to demand, or something along those lines. So I interpreted this to mean that even though I had the AC OFF, the fact that I had the temp setting at LO meant the compressor would run?
So if I ever need the full power of the engine (say at the track), the only way to have the compressor really OFF is to turn off the AC system all together? or set temp to outside temp and keep AC light off? Is there's no truly passive vent in this car?
Sounds messed-up to me. I read in another thread ( see post #14 )that when the car is started up, the compressor will automatically, then cycles off - so maybe that explains it?
In any other car I have owned, when you say "Off AC," then the coldest the air coming in the vents can ever be (no matter where you have the temp set at) is as cool as ambient air.
Made me wonder if my compressor was stuck ON or something. So I called service adviser, who did some research and indicated that the AC logic is "variable displacement" (or something like that) and that it never really shuts off, but responds to demand, or something along those lines. So I interpreted this to mean that even though I had the AC OFF, the fact that I had the temp setting at LO meant the compressor would run?
So if I ever need the full power of the engine (say at the track), the only way to have the compressor really OFF is to turn off the AC system all together? or set temp to outside temp and keep AC light off? Is there's no truly passive vent in this car?
Sounds messed-up to me. I read in another thread ( see post #14 )that when the car is started up, the compressor will automatically, then cycles off - so maybe that explains it?
09-04-2009, 12:59 AM
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2007 E63 w/P30 and Eurotech CF Diffuser
Your experience is identical to mine. I did not dig in so much with the dealer as you did.
As for a passive vent? Well if I turn the system off air flow is minimal. If I force the fan to minimum and have the pano tilted open I get a fair air flow
So this is not a noob question. This is a question that no one on the forum has a definitive answer to. If it had to do with wheels or lowering we would know all about it.
I think there are some places to research this. I will post again if I find anything.
As for a passive vent? Well if I turn the system off air flow is minimal. If I force the fan to minimum and have the pano tilted open I get a fair air flow
So this is not a noob question. This is a question that no one on the forum has a definitive answer to. If it had to do with wheels or lowering we would know all about it.
I think there are some places to research this. I will post again if I find anything.
09-04-2009, 01:14 AM
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2007 E63 w/P30 and Eurotech CF Diffuser
OK, that was easy.
It uses a clutchless compressor. These are nearly the same. It indicates the ability to control between 2% and 100%, which means it is really never off.
http://www.mercedestechstore.com/pdf...%208-30-02.pdf
http://www.mercedestechstore.com/pdf...2008-30-02.pdf
EDIT - This is getting interesting. Read this http://blogs.howstuffworks.com/2009/...pressors-work/
The paper refered to is here http://delphi.com/pdf/contact/brochu...ompressors.pdf
All good stuff.
It uses a clutchless compressor. These are nearly the same. It indicates the ability to control between 2% and 100%, which means it is really never off.
http://www.mercedestechstore.com/pdf...%208-30-02.pdf
http://www.mercedestechstore.com/pdf...2008-30-02.pdf
EDIT - This is getting interesting. Read this http://blogs.howstuffworks.com/2009/...pressors-work/
The paper refered to is here http://delphi.com/pdf/contact/brochu...ompressors.pdf
All good stuff.
Last edited by Jon2007E63P30; 09-04-2009 at 01:22 AM.
