mcoady1

Anyone else have their air conditioning temperature become mediocre? Its cool now, but not cold and quick like it used to be, and when it gets cold it takes a bit of driving. Scanner said refrigerant is 13.5 bar on 83 deg F day, did have a power supply low historic code saved. Wondering about anybody else's experience with this. Compressor engaging?

oldmangrimes

On my 2013 GL450 it's never been very good, but I bought it two years ago with 80k miles, so I don't know how good it was new. The compressor is running, it puts out cold air, just not ice cold. It's not as cold as my other cars that have good AC. I've got the panoramic roof so it gets pretty hot if the windows are rolled up and it's parked outside. I have a iCarsoft MBii scanner, and I just read that it can check the pressure so I will do that soon. I'm curious to hear if others have had good luck with simple recharges on these.

arsupisemnet

Change between modes... Most likely you are on diffuse...

chassis

Scan using XENTRY. Detailed diagnostics and operating parameters will be displayed showing target and actual values.

Evap outlet temp should be in the 40s.

mcoady1

Dropped it off at mechanic today, he said pressure was low and recharged it. Couldn’t find leak but he put dye in it to trace it down should it get low again. We’ll see!

chassis

Look at the vapor line from compressor to condenser. Mine is slightly leaking from the crimp at the compressor. It is a slow leak and XENTRY says all the temps and pressures are in spec. AC blows cold so I’m keeping an eye on it. I have the hose in case it needs to be replaced, the parts guy said I bought the last one in the country last year.

E55Greasemonkey

It's normal to have to evac and recharge these cars every 5 years or so. The freon doesn't last forever, some of it leaks, some may break down chemically, but this is essentially a maintenance item. Newer cars hold such a small amount of freon that a small loss of say 10% noticably affects the cooling capacity.

sdwtchlvr

I had mine charged up last year and it’s been great since.

Before it was blowing not so cold and I noticed a faint swirling/swishing sound coming from the vents. Did some reading online and read that sound can indicate low refrigerant.

I have a 2013 550, purchased in 2018. Just for reference.

Tiffany's GL450

My wife's 2013 GL450 blows cold on the Passenger side but the Drivers side is cool, at times its even just air and not conditioned air. But the passenger side stays cold, after some driving the Drivers side seems to be getting colder but not like the Passenger side.
Is the fault of a blend door actuator or temp sensor of some sort? Or do I need to have the system cleared of the old freon and new freon put back in?

Chad

CaliBenzDriver

Forget the parts canon, parts are hard to come by these days!
You need to have it scanned to check what the AAC computers has to say.
Actuator and sensor are excellent guesses. Scanner will tell!

Usually the bad temp sensor is on passenger side, broken during filter service.
Speaking of which... do replace or remove cabin air filter to get good flow over the blower ballast module.

Tiffany's GL450

Filters were replaced at the B Service with K&N and Factory Filters earlier this year.
Is that temp sensor in the immediate area where those 3 filters are at? Would you know the official name of the temp sensor, like AC Temp Sensor or something similar?
Thanks for the help!

Chad

CaliBenzDriver

... there is a dozen sensors involved in Mercedes A/C - This system definitely far from basic.

The most frequently disturbed sensor is on the passenger footwell cover but I wouldn't try to get away with only guessing ... scan

Tiffany's GL450

Scan, looks like a dealer or shop will have to do it. I only have a basic-generic-cheap scanner used for reading codes only.
Rats!

Chad

Tiffany's GL450

Do the MB's use a particular scanner or would a Auto Shop that uses Scan II or OBD Scan Tool be able to determine what the AAC Computers have to say?

Chad

chassis

XENTRY is the MB dealer diagnostic tool.

CaliBenzDriver

an iCarsoft handheld scanner will read everything AAC module has to say.

You need a $150 Benz specific scanner not a basic $39.99 special...

Xentry is the reference 👏

BenzNinja

iTrader: (4)

I'm here

Tiffany's GL450

Thanks gents!

Chad

Tiffany's GL450

So the Air Conditioner has no codes, a friend of mine has a Matco Scanner and hooked it up. The scanner revealed 93 codes that varied from Communication or Open Signal / Internet Signal Loss or Missing Message / Low Power Supply and other codes that I would consider nuisance alarms or codes. Nothing related to the performance of the car or the Air Conditioner.

I find it odd that none of those codes or faults showed on the Display, it is clear, only the scanner revealed these codes.
The one parameter or fault I was looking for: AC - Air Conditioning(N22/7) showed no faults. But yet the AC is as first described, cool on the drivers side, cold on the passenger side.
I'm going to take it to a shop and have the ac system evacuated and the Freon replaced, see if that fixes the problem. Is this one of Mercedes Letter checks perhaps? Like fluid changes and filter replacements at a pre-determined intervals?

Chad

Tiffany's GL450

I think I might invest on a more robust scan tool, one that I could scan the Wife's Mercedes and my GMC Truck and my Camaro.
I seen a guy on here using an iCarsoft scan tool so I found their website and seen different models.
One in particular shows to read multiple vehicles, the iCarsoft CR Elite scan tool, (https://www.icarsoft.com/Product/s-3..._cr_elite.html) any thoughts on that scanner or perhaps a better scanner for less the $300?
I think it's time to upgrade!

Chad

BenzNinja

iTrader: (4)

see you in 3 month's
good luck

Tiffany's GL450

Tell ya what dude, if you hadn't been a ***** saying "see ya in 3 months" I might have considered your service. But instead you can go pound sand!!
Please stay off my Post, I'm looking for help not wise *** comments!

Chad

CaliBenzDriver

a while back @chassis shared his solution to increase A/C cooling was to decrease R134 load... I buy that.
Mine was to wrap the A/C lines to minimize engine heat transfers.
Thinking it over both of the above solutions decrease pressure to increase cooling!

With higher heat, the pressure of the high side liquid increases and the compressor gets a higher head to pump gas around.
The resulting pressure increase on the low side limits the evaporation of a warmer liquid into gas.

Tiffany's GL450

Thanks man, I plan on taking the car to a shop this week to have the AC looked at

Chad

CaliBenzDriver

With the level of heat this summer, frigid A/C is not an option - Let us know what made a difference to get your A/C cool again... 😎