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Help me troubleshoot my AC, please! (2013 C300 Sport)
Let me start off by saying that I'm not very car savvy at all so please bear with me and my laymen terms.
Last summer my AC started blowing warm air. I bought the little refill tank from Home Depot, filled it up, problem solved.
This summer, it started doing it again. Essentially, this is what happens:
If my car has been sitting in the shade, even if it's very hot outside, my AC will work fine when I start up. If I drive it in the evening or if it's cooler out, AC works fine.
If my car has been sitting out in the sun, my AC will immediately start blowing warm air. When the issue is occurring that warm air is blowing, my car legitimately sounds like a jet engine from the outside. I don't know if that's the AC compressor or engine fan or what.
I bought the iCarSoft MBII on Amazon to check for fault codes and it didn't come up with any (though from what I read, this thing isn't the greatest.)
I did do the climate control diagnostic system, while it was sitting in the garage, and here is the numbers I got while my AC was on low (AC was working well at the time):
Here it is after I put the AC on max. It blew cold air for about 30 seconds, then warm air started coming out and my car became super loud again (engine area, once again, not sure where the sound comes from)
I apologize if this is a stupid question but I was hoping I could figure this out before bringing it to a shop and dropping a ton of money on it. I guess I just want to know what I'm in for.
W204 C200, BMW E30 M3, 1980Gt Mini, Toyota Corona, KTM 200 EXC.
Hi
Okay I will try and help you with what I know, the data stream you have is superb by the way.
The noise you hear super loud is the cooling fan it is going Flat out and the reason is the 27.9 bar = 400 psi!
Most average cars top out at around 250 psi at like 2000rpm (Mercedes may be different) with a Hi sense switch for coolant temperature or coolant pressure this drives the fan speed to max.
Very High coolant pressure is in my experience either over charged or blocked up cooling fins on the condenser or the cooling fan not working.
First step is try and have a very good detailed look at the front condenser being clogged with dust in the fins can cause these same symptoms if you can water blast it or wash it some how.
Next would be either remove some of the A/C gas you have installed or preferably have the system evacuated and refilled with the correct amount.
Hi
Okay I will try and help you with what I know, the data stream you have is superb by the way.
The noise you hear super loud is the cooling fan it is going Flat out and the reason is the 27.9 bar = 400 psi!
Most average cars top out at around 250 psi at like 2000rpm (Mercedes may be different) with a Hi sense switch for coolant temperature or coolant pressure this drives the fan speed to max.
Very High coolant pressure is in my experience either over charged or blocked up cooling fins on the condenser or the cooling fan not working.
First step is try and have a very good detailed look at the front condenser being clogged with dust in the fins can cause these same symptoms if you can water blast it or wash it some how.
Next would be either remove some of the A/C gas you have installed or preferably have the system evacuated and refilled with the correct amount.
Dave
Hey Dave,
Thank you for the advice!
Just to add to my ignorance, what exactly are cooling fins? I tried googling images and looking up videos on youtube for steps on how to clean them (or what they even look like) and I came up with nothing. Once again, I apologize for my ignorance and I appreciate the help.
W204 C200, BMW E30 M3, 1980Gt Mini, Toyota Corona, KTM 200 EXC.
The cooling fins are part of the condenser what the air touches as it passes through the condenser like very small passages, road dust and leaves can block it up so not very much air can be drawn through the condenser.
I hope that makes sense.
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