Smart Car Air Conditioner Problem

[ktlobb11]

I’m posting this here because I figured this is the location with the most Smart car owners. I had to take my first longer trip with our Smart (2016 Smart) last night covering 265 miles with a 2 hour break in the middle. After traveling for about 80 miles on the first leg the interior of the car was getting warming and I noticed that there was very little air flow out of the air conditioning vents and about 10-20 miles later there was for the most part no air flow. If I played with the fan setting and turned it to high it sounded louder and if it was blowing air but nothing coming out of the vents. After dinner with my son’s family I got back on the road and the air conditioner was working fine and air flow was back to normal. Then sure enough at about 80 miles into the 2^nd leg of my trip the same thing happen and again 10-20 miles further and very little to no air flow. I’m taking it to Mercedes tomorrow but I know they’re not going to replicate the problem. So I’m taking a chance that someone else with a Smart has already experience the same thing or maybe has an idea of what would cause this?

Thanks for any feedback.

Kevin

[TreyandSusan]

A recent thread that discusses similar issue.

[sclord2002]

What you are describing sounds like the evaporator core is icing up. If so, the ice blocks the air flow and when you stop, the ice melts until you run it and refreeze it, blocking the air flow again.  A low refrigerant charge can cause that, but there could be other things at play.      Charlie

[Nigel]

It sounds to me like the evaporator is icing up.  When you shut it down for a bit it thaws out and works again for a while.  I believe that can happen with high humidity and a low refrigerant charge but I’m not an AC tech.  

 

Nigel

Charlie wins the race

 

[ktlobb11]

Thanks much guys, I'm not very "Smart" (Pun Intended) when it comes to automobiles but that makes sense and I'm going to take that information to the dealer with me. If that was the cause then being that I was in Florida and it was hot I should have pulled over for 5 minutes and that probably would have been enough time for the ice to melt. Would have been a good experiment. I'll respond with the outcome later today.

Thanks Again

Kevin

[Dennis M]

Our latest smart has pretty good AC, but the earlier ones were somewhat marginal. One thing to keep in mind is that AC in Europe is intended to keep the car from getting too hot, not to make it cold.

Anyway, evaporator ice over can happen with any car in humid conditions when AC is running full blast. Two things that might help: set the temp warmer than the max cool level which gives the compressor a chance to recycle and run the fan at a lower speed. I used to drive 50-60k per year in the midwest (yeah, I was a road warrior) and both of those tricks have helped when I had a car that tended to freeze up. I have found that running the fan slower allows the air passing over the evaporator to cool more, thus cooler air out of the vents.

[ktlobb11]

Thanks for all the feedback, so this is what the dealer did and said. First they said they couldn't find anything wrong but they did add Freon and/or re-charged the AC system. They then stated that if your running the car for an extended period of time at the same speed that the AC system will shut down or slow down to conserve fuel and to not allow the engine to over heat. So I don't know how knowledgeable they were at this dealership about Smarts but the evaporator icing up seems to make a lot more sense to me. I will say we set the temp to its coldest spot and run the fan on high to get started so I do believe I'll make some adjustments to this moving forward. If it happens again I also try slowing down for a bit on just pulling off and stopping for 5-10 minutes to see what happens.

Thanks Again for the feedback, it will certainly help me in the future if it happens again, luckily I don't plan on using the car for long trips to often.

Kevin

[HERO Maker]

1 hour ago, ktlobb11 said:

I will say we set the temp to its coldest spot and run the fan on high to get started so I do believe I'll make some adjustments to this moving forward.

Not sure if you said it elsewhere, but remember to bring that temp setting up to something that is going to be comfortable, yet allow the system to cycle.  Plus, I believe there is not difference in cooling by setting the temp to the lowest amount.  The system will not cool any faster by doing that.  It will get to the appointed setting and then cycle.  If you forget and leave it on 60, you probably help create the freezing situation.  Just my thoughts and something I've be telling the DW for years!

[ktlobb11]

Yes I agree, my DW drives the Smart all the time and has it set at 60 so I don't bother changing it when I drive it. So I think I'll try and change her thinking with that. I think that's a good idea and "Dennis M" stated the same thing. I actually like to use the Auto setting for the air conditioner and set the temp at say 70 so I'm also going to try that. Unfortunately I don't have the problem driving around town or on short trips this just happen on the longer trip but I think I'll change the settings for all driving.

Thanks

Kevin