DevilsAngel

Ok so its summer time now and its starting to get really freaking hot. I went to go turn on the ac and nothing but hot hot hot air blows out. I talked to my mechanic and he said its probably just a small leak somewhere, but then my boyfriend thinks that the ac just needs to be recharged. SO I'm wondering are Mercedes known for the ac leaking? I'd much rather not spend $200 on fixing it when I've only had the car for a few months. What do you guys think?

rsnpride

In my bimmer, I used to have hot air blow out, but I got the a/c recharged and now its blowing cold air.

I just experienced the same problem with my CLK about 2 weeks ago. I thought the a/c needed to be recharged, but it turned out to be more than that. It was a leak.

superstar

When i bought my car used , it was blowing hot air.so i just recharged it .Now after 3 years , the cold air is starting to get wormer and wormer , i know it will end soon! I think i have a very small leak somwhere.but i can mange to live with that kind of leak!! From what i heared , they have to remove the entire dash board ,in order to fix the leak. If i were you , i would recharge it first, then wait . You may have a small leak , just like mine. Good luck

CLK FAN

You do probably have a leak...but here's a few good questions...did you ever try it out before you bought it? Was it cold before? Because if it was cold before and it was only a few months ago then you have a bigger than small leak. I suggest you just waste about $40 - $60 and have it recharged and see how long it takes to come out....if it's quick than get it fixed but if it stays cold for a long time it could have just came out over a long period of time while the car sat where ever it was before you bought it. Or you can just have it service and fixed...but it will be maybe a few hundred dollars.

I know that there was a thread in here once about our a/c units seals going bad if it sits to long without being used. I use mine regularly because I live in LA, CA and you need it if your sitting in traffic with a pimp suit on : .

TresX

The AC system in these cars are sealed and should never leak.
How do you know you have a leak in your system? Is the EC light on? Did you check through the A/C diagnostics to see the freon level? If you did and you do have a leak somewhere, you have to determine where it is. Don't just refill and see how long it goes. Refill with UV dye and FIND the leak. Here's an easy way to diagnose your problem....with the car on, hold the rest button until the AC systems menu pops up. Check the freon level (it will be displayed in bar), as well as the the temp levels of all sensors (especially the evaporater temperature sensor).

Is your EC light on? If no, do you hear the compressor engaging? Do you know what the hell I'm talking about? (sorry couldn't resist). anyhow...I'd be more than willing to help...if you provide more information. Best case scenario, it's just your compressor or condensor/radiator. Pretty cheap/easy fix. Worst case scenario...it's your evaporator....then you have to take apart the dash and it gets me$$y. If it is your evap....make sure they change all of your vacuum elements while they are in there. Don't want one of those to fail after you put it all back together........

P.S. Actually your best case scenario would be that you don't have your EC light on and the problem is just your evap temp sensor. $75 bucks.



P.P.S. Everything I tell you is from personal experience with my own car. I must have fixed EVERYTHING on it thus far. (by myself, mind you) So I'm not just blowing smoke here.....

CLK FAN

Listen to the guy with a picture of a Porsche as his profile pic. The truth is if you spend some money you'll find out what's wrong with it.

DevilsAngel

ok so i held the rest button and only numbers came up. on the left side it showed a 1 and the right side it showed 110-112. does that mean anything? The ec light didn't come on, so we'll say that could be a good sign. I did hear the compressor engaging, atleast I would assume that was the noise I heard. (still a beginner learning things about my car!)

scottster77

yes! its a good sign that the EC light is not constantly on... so that means the leak must be small.. best thing is to have it checked out...

few weeks ago my EC light was finally went off and its blowing nice cold air.. no more rolling down the window half way pretending that i have AC..

usually if the EC light is on.. that also means theres a leak, something went bad or its out of freon/refridgerant.... if the light is on for awhile.. once the freon/refridgerant is recharged.. the systems needs to be reset...

to find out the problem.. running a dianostic on your car should cost about $80... make sure its not some general mechanic shop.. instead take it to a specialist that deals with benz...

DevilsAngel

ok so recharded the ac. the air isn't as hot as it was. its only warm now. how should it run for before it should blow cold air? and does anyone know what all the numbers are for on the ac menu? some of them read 0 one reads -21, and the rest read between 90-105. i don't have a menu to know what they mean. help???

Redtallman

do a search on ac diagnostic on this site it should pop up for the codes that u are seeing, also if this car is like the e320 then it has two valves that open and close the the hot water from the engine, that could be stuck open i wiil check and see if i can find the post and foward it to ya

TresX

I have the actual list on my computer at work, I can post it for you on Monday. From memory, I believe the 2 values you should be interested is 5 and 7. 5 being the evap temp sensor value and 7 being the refrigerant level (in bar). Check those 2 values when the car is cold and report back.

You never answered my question as whether the EC light was on or not before you refilled your system. The fact that you refilled your system and it still doesn't blow cold is a "bad" thing. I assume it's not on anymore since you "refilled". Do this....turn the ignition on (turn the radio off)....then turn the ac on 1 click +. You will hear a "clicking" sound from the front of the car. (this is your compressor engaging) If it doesn't "click" then you may have a problem with your compressor. But first things first, check the values for 5 and 7 and report back.

Redtallman

here u go https://mbworld.org/forums/showthrea...blems:naughty:

DevilsAngel

Ok the EC light was off before I refilled the system. It was holding pressure and not losing anything when the gauge was connected. It doesn't blow hot air anymore but its definitely not cold, still just warm air. I still hear a clicking sound so that must be good. And #5 reads 126 and #7 reads 5.

p.s. i did a little more research and found the list of what the different numbers mean

TresX

AHA!!!! THERE YOU GO!!! There's the problem. Your evap. temp sensor is reading 126 degrees!!!! Unless it's REALLY hot where you are, it is BAD The value for #5 should be ambient temperature OR a temperature SIGNIFICANTLY LOWER than ambient temp. when the AC is on. In fact, if you check the car in the morning (before you turn it on), the value for #2 should be the same as #5. #2 is outside air temperature value. If they aren't the same, and 2 seems right and 5 is WAY off.....Go to the stealership...get yourself an evaporator temperature sensor and swap it out. It is located under the driver footwell along the firewall. You won't be able to see it without a flash-light and will still be a little hard for you to find when you do have one. (the replacement part is slightly different looking from the original.


Bad news is...you refilled a system that didn't need refilling. (for future reference...if the EC light is not on, then you shouldn't be worried about refrigerant). Good news is...you're only showing 5 bar of pressure (which is strange if you didn't have the EC light on and you added more). Regardless, you need a little more. But change the evap temp sensor first! I'll bet that will fix it! If you hear your compressor engaging....I'm almost SURE it will fix it.

TresX

P.S. I just saved you a good 3-4 hundred bucks.....(diagnostic time, parts/labor) from the stealer....


IF that is you in the avatar.....I'm sure the boys here won't mind if you make payment in some more recent photos. We can even start a poll on the differnent positions

DevilsAngel

So I checked the temp again this morning and there was a 10 degree difference between #2 and #5. Luckily its going to be rainy all week and I can wait until this weekend to go get the sensor and change it out. But my ec light keeps going on by itself but I'm able to turn it off if I turn off the car and start it back up. Does that mean anything or am I ok still as long as I can turn it off?

P.s. sorry guys that isn't me in that picture. I'm not quite that tall. I guess it'll have to remain a mystery on whether I look like her or not. Maybe in the future you all will see me with my car when I post new pics of it up. but for now you'll have to assume I do look like her....

TresX

check again tomorrow morning and compare the values of #1 & #2 to #5. 1 is inside the car. 2 is outside the car. and 5 is the evap. temp sensor.......so just to be safe...make sure 5 doesn't equal either 1 or 2. If it doesn't show the same value for either....then for sure it is bad.


The EC light coming on by itself is not really a good thing....can you toggle it off by hitting the EC button? or do you have to restart the car? (by the way...check the value for #7 tomorrow morning, just in case). When you refilled, did you use UV dye?

ThrillKill

Extremely helpful. The CLK and ML both have had flawless a/c since purchase. Both completely flatlined this year at the same time. Took the ML for a recharge and it's so so (I suspect the cabin filter needs replacing). After reading this, I'll check out the CLK....ummm when I sober up.

DevilsAngel

ok so when i checked it this morning #2 was pretty on key with the actual outside temp, #1 and #5 were close in range, about 10 degrees higher than the outside temp. when i refilled it i didn't use the UV dye. and when i checked #7 this morning and this afternoon it went from a 5 down to 3.

the EC light is on when i start the car, but if i turn the car off and just turn the power on then i can turn the light off. but it will come back on about 10 minutes after i've been driving and i can't turn it off when the car is running. So basically its looking like i'm gonna have to take it to the shop.

TresX

OK....you have a refrigerant leak. You should have used the UV dye (it's the same thing...a can with refrigerant in it, mixed with uv dye) but since you didn't....the tech is gonna have to refill again with UV dye to find the leak. Either that or use a sniffer. Just let him/her know you already refilled the system so that he oils the system when he refills it this time as well. (you can't just keep adding refrigerant to a car w/o oiling the system) Keep your fingers crossed......hopefully it's just the compressor. (Still a $800 fix at an inexpensive independant mechanic) 1k normal pricing and 1500 easy at the stealer.

ThrillKill

I don't really follow this.

My numbers are:

1-95
2-68
5-150

It's approx. 90F degrees outside. Thanks.

TresX

Your evap temp sensor is definitely BAD. Change it and i can guarantee you that you will get cold air. I'm sure there are ways to "trick" your car into giving you cold air, but eventually it will go hot, right? Trust me dude....change it out and you'll be golden.


P.S. Try this....start the car and turn on the AC. DO NOT HIT THE ACC. PEDAL. The air should be cold and stay cold. (granted your compressor is engaging and you have refrigerant) What is your value for #7?

ThrillKill

#7-5


[QUOTE=TresX.


P.S. Try this....start the car and turn on the AC. DO NOT HIT THE ACC. PEDAL. The air should be cold and stay cold. (granted your compressor is engaging and you have refrigerant) [/QUOTE]

Nothing but engine-hot air

TresX

OK...your refrigerant level is a little low, but not enough to make you get hot air. Is your compressor engaging? IE. do you hear a clicking noise from the front of your car when you first turn on the AC? If so.....I'm willing to BET that if you change your evap. temp sensor....you WILL get cold air. Look at it this way....check it again in the morning. If you have a reading of something anywhere near what you had today....IE 100+ when the car is cold and ambient temp is obviously not 100+.....you have confirmation that that sensor is bad.

ThrillKill

I appreciate your help.

On the CLK, I can hear a click and the engine idle drops a bit so I assume the compressor is engaging. I'll try what you said in the morning. What # should the refrigerant level be? Unfortunately the ML does not have climate control, is there another way to detect a faulty sensor? My ODB2 scanner is not detecting anything.