ricardovasco

Hi all. I realize my a/c was not that good after 10 days I bought my car ( CLK 500 2004). The air started to come off warmly from the output left side. After that I reseted the a/c system pressing the 2 buttons informed here ( recirculation + ...) The a/c is better now. I mean, it is cold if you put your hand in front of the output but I think its not enough to fill the whole car. Sometimes I think it gets better when the car is in movement. I went to 3 especialists today. The first one said that the compressor is not good... need to be replaced..etc . He put the tools to measure the compressor pressure and air level. He said the compressor level hand was not moving so it indicated it was not good. The other 2 guys said the opposite. The compressor is ok and the hand MUST be stopped so the pressure is keeping the same level. The air level was also ok. What do you guys think? I've never had a MB before and a friend said the a/c of the CLK is normaly sooo cold and efficient. I can say its fair from that. Of course I live in Rio de Janeiro(30C is quite common here) and got no insulfilm on my car which is also black. However, my GF got a Corolla ,black and the a/c gets sooo cold. I got 3 months to complain about that with the store which sold me the car so they will fix that for free. Now I need to know if the a/c is like that or if it has any anomaly.
By the way, I realized there is a very hot compartment under the panel ( driver's side). There is a plastic cover which is getting soooo hot. Whats that? The guy said it would be the warm air output( not sure how it is called in english) and I could open this cover and isolate that with a thermal isolation. Is it normal to your cars? Why does it get too hot? How to fix that? Maybe its the reason the A/C is not getting so cold.

Thank you all!

Regards
Ricardo

ricardovasco

Anyone?

Rudeney

There is a heater vent under the dash, coming out beside the plastic panel near the center console. My guess is that you either have a damper problem, or an A/C system problem. It's just going to be hard to diagnose without looking at it. I can tell you that a common symptom of A/C problems is hot air on the driver's side, while the passenger side stays cool. I suspect there is a tie-in with a damper and an expansion valve that causes this. It happened on our C240 - the passenger vents would blow nice cold air, but the driver's side was "warmish". I charged it with about half a pound of refrigerant and all was fine.

ricardovasco

Thanks Rudeney! If you were me , what should you do first? I mean, people here really want to replace the compressor to make more money. The other 2 mechanics said the compressor is ok...air pressure is ok...etc. When the car is moving the air gets better. Sometimes is ok. However, when the a/c is off and I turn on, the air gest a little crazy. First the air comes on my feet and then it comes from the regular outputs.
What about the heater vent ? Its getting sooo hot. Do I need to replace anything or isolate? I need some help because here in Brazil the MB dealer and all others would take my pants off and the garages don't know the car that good.

I really think its not a a/c mechanical problem like compressor... condenser. It looks like a electronic problem or something like that.

Thank you so much.

Regards
Ricardo

Rudeney

So when you did the A/C test/reset, did the lights stop flashing? If not, then you have a damper control problem. I they did stop flashing after 20-30 seconds, then we can probably assume everything is fine mechanically. I would then look to the refrigeration system. You said they put gauges on the system and said the refrigerant level was good? If that's the case, then it's not the compressor. Another possibility is a bad temperature sensor in the cabin. Really, all of these things are going to require a good mechanic with proper tools to diagnose. You may have to go to the dealer and at least get them to pull the diagnostic codes.

ricardovasco

I just reseted it again to see that. They stopped flashing after 30 seg. Only the Front Defrost light still on( not flashing). I realized again when I turned the a/c on that the air came first only from under the dash. After 5...8 seconds it came from the dashboard and stopped coming from under the dash.

ricardovasco

Thats the result when the third guy was testing the a/c. Is it normal? The guy said yes. The pressure and the gas quantity were ok.

Rudeney

If those gauges are connected properly, that doesn't look right. Typically, the suction side (blue gauge) should be around 35psi. Yours is at 32, so that's pretty close, let's call it good. However, the high pressure side (the red gauge) should be over 150psi, but yours is showing around 30psi. Now, it's possible that the gauges are not properly connected, and they are both just reading the suction side. I know the high pressure valve is a bit hard to find, so maybe the mechanic got lazy. That would be my guess - I don't think you could get the suction side down to 32psi and not have the pressure side over 150. But that's just a guess - it's hard to say without "being there".

billyhead1

When I overcharged my a/c system using the DIY kit from O'reilly, I experienced similar symptoms to what you describe. Panel on the underside of the dash very warm/hot to the touch. I was on a long drive, and experimented with using the "a/c off' button, and that panel got hotter when the compressor was running, so it was at least somehow related. As I recall, I performed the Climatronic diagnostic easter egg procedure at the time when I overfilled the car, and that it did the normal blinky-light thing.

After the dealer removed the excess refrigerant and set everything right, the under-dash panel does not get hot. So, to echo Rudeney, I would guess that you have a pressure or fill level problem.

ricardovasco

Thanks Rudeney. I think only the blue side was connected correctly. I think the guy commented that red side to be connected would miss some gas . Is the blue side only ok? What does that mean? The compressor is not working well or there is no enough gas?

ricardovasco

Thanks Billy. What do you think? Does it have too much gas or I need to fill with more? Or its a mechanical problem? The blink test was ok. The lights stopped blinking after 30 secs.

Rudeney

You need to get a qualified mechanic to look at this. He needs to connect gauges to both the high and low sides of the system. If the low side is too low and the high side is too high, then the system is overcharged. If the low side is too low, but the high side is good, then it could be a problem in the system - bad compressor, clogged drier, bad expansion valve, etc. Again, this needs the attention of a competent mechanic.

ricardovasco

I will try to find some expert and honest person to do that. Today I drove the car for 30 min. The air was confused. It started ok..cool...etc.. but then it was warm...the air stopped to come off from the dash and started to come off on my feet so I changed the direction button for down also. When I turned it back for the dash, the air came with a burned smell. I stopped the car to change the tires. The way back home was perfect. The air was cool all the time. Thats sooo crazy. There was a guy in that garage who is specialist in A/C. He said it was normal and I should bring him the car when the problem is happening lol

I think its something with the expansion valve. I've also heard of 5 small a/c motors and one of them can be broken. A guy told me they are responsible for the air directions...warm ar/cold ar...etc... whats is that?

Thank you Rudney. Im just persisting on that with you because I can't trust in anyone here. They see a Mercedes and think you are a billionaire ; ))

Rudeney

So the airflow changed direction? That wouldn't have much do to with the refrigerant system. You said you did the A/C reset/test - did the light stop flashing? Maybe the problem is a bad temperature sensor or A/C control panel and has nothing to do with the refrigeration system at all.

ricardovasco

Yes, I did. The lights stopped flashing after 30 secs. Only the Front Defrost light still on. How to check the temperature sensor?

Rudeney

That will require SDS. It can give readouts of the temperature sensors, sunlight sensor, and humidity sensor.

ricardovasco

Hi all! I was just checking the Star Diagnosis results of my car when I bought it. There are 4 errors on K-KLA ( A/C system). The mechanic said all errors gone after he reseted the system. He said its normal . Is it true?

Any way, Im attached the errors on my a/c system ( its in portuguese but there is the code error so you probably know what they mean). If you don't undertand, ask me . The B1205 is the refrigerant which was very low. The B15B8 and B15C0 are something like the butterfly vent ( left and right) are hanging or blocked . The B15A0 is like butterfly defrosting(right side) is also hanging or blocked.

Do you think one of they can be the reason of my issue?

Thank you guys.

Regards
Ricardo

Rudeney

You definitely have ventilation damper problems. I would have it scanned again to see if the same errors are stored. Then reset them, drive a day, and check again. I'll bet you have some bad servos in the damper system and they are working intermittently. Also, have you had the refrigerant recharged? If so, you should not have a low refrigerant error unless there is a leak.

ricardovasco

Thanks Rodney.

I remember the mechanic said after he reseted the only error stored was the "bad communication with the component H3/1( alarm siren signal.... ) ". code B1078.

I will ask someone to scan my car again once it was scanned in Sao Paulo just for a safe purchase.

ahmedhossame

I think I'm having similar codes for the butterfly vents. They are not working. How difficult to replace them. I have the WIS at home but I don't know really how to use it to show the steps its little not user friendly.

megacrazy

Their location is not exactly easily accessible...If I was gonna do it I'd probably rip out the entire dash and replace all of them at the same time