CopperDesigno

I noticed yesterday that with the top down the A/C wasn't blowing cold air, it was actually kind of hot. I tried all of the vent selection on the dial. I also switched it from EC to non-EC a couple time to see if that setting was stuck. Then that night I had the top up and still no cold A/C. Ok now your thinking my air needs to recharged. I tried it again this morning and it works with the top up and down? I am really confused.
At first I thought it was something with the car where if the top was down, the computer turned off the A/C becuase it figures that the driver wouldn't want to use it. but after my night time experiance, I don't know anymore.

Brian_R170

The A/C should work with the top down. If it didn't, I'd have traded my SLK in a long time ago.

Lots of possible reasons for your problem, including

- heater valve is malfunctioning allowing hot coolant through the heater core
- Mixer (flap) is malfunctioning.
- Electrical problem causing A/C compressor not to kick on.
- Coolant is low, right on the edge where the pressure sensor sometimes senses it's too low and sometimes not.

CopperDesigno

Thanks, maybe the body shop didn't replace the compressor or the another part of the system correctly. I'll have them review it the next time it goes in.

trex_47e

I agree, the a/c is a must with the top down in the summer. I would melt if it didn't

wrio

I moved from Boston to Orlando, FL and as you all know, the heat here is oppressive... Now I have to have the AC on, and with the price of gas the way it is, I'm curious to know from you guys if you noticed a huge difference in gas usage when the AC (and when the heat) is turned on (SLK 230, 2001)...

thanks

Brian_R170

I keep a log of the fuel economy in my SLK32. I drive with the A/C on for 8 months of the year. There is about 1mpg difference between the months where the A/C is on and when the A/C is off. That is a combination of the increased load from the A/C and the decreased efficiency of the intercooler.

That's about a 5% decrease in fuel economy for a 230 that averages 20mpg. If you drive 12K miles per year and pay $2.50/gallon for gas, you'd be paying an extra $1.45 per week to use the A/C.

You're the guy that posted wondering about using lower grade fuel to save money, right? Just try to cut back on your driving as much as possible. You'll save alot more money that way.

wrio

Yeah.
Not taking in consideration California, I believe I was living in one of the most expensive areas of country for gas prices. While driving down from Boston to Orlando, I noticed that in Georgia, the Carolinas and in Florida the price was much much lower (about 15%). I'm not sure if it had to do with taxation or if the gas companies think that people from the Northeast are wealthier or what.
I spent an avarage of 8 hours a week, in/out the city, driving in MA due to my comute to clinics etc I used to fill up my tank 2x a week.

wrio

Yeah.
Not taking in consideration California, I believe I was living in one of the most expensive areas of country for gas prices. While driving down from Boston to Orlando, I noticed that in Georgia, the Carolinas and in Florida the price was much much lower (about 15%). I'm not sure if it had to do with taxation or if the gas companies think that people from the Northeast are wealthier or what.
I spent an avarage of 8 hours a week, in/out the city, driving in MA due to my comute to clinics etc I used to fill up my tank 2x a week.