E-Class (W211) 2003-2009

E500 A/C Question

Old 04-13-2008, 11:02 PM
Senior Member
Thread Starter
Join Date: Aug 2006
Location: San Diego
Posts: 393
Received 2 Likes on 2 Posts
2011 E350 Bluetec, 2007 GL450, 2003 E500 (GONE)
E500 A/C Question

Guys, my car (2003 E500) is almost 7 years old (yes, it was made in July of 2002!) and has about 55K miles on it. In the last couple of days it has been extremely hot in Southern California and I noticed that my air conditioning wasn't delivering as much of cold air as it used to. Can anyone tell me if A/C should be recharged once in a while? Or is it an indication that there is a leak in the system and I have lost some of freon?

Thank you.
MB500 is offline  
Old 04-13-2008, 11:19 PM
MBWorld Fanatic!
Barry45RPM's Avatar
Join Date: Mar 2004
Location: Ft. Lauderdale Area, USA
Posts: 4,977
Likes: 0
Received 9 Likes on 9 Posts
2015 ML 350
Basically, a car A/C system is a closed system, much like your refrigerator is at home. In theory neither system should ever need a recharge of gas unless something malfunctions which causes the system to dump gas.

Your car's A/C system is subjected to shakes, rattles & rolls, which will always lead to a failure somewhere in the system causing a loss of refrigerant either due to too high a pressure causing the system to dump, or due to another part failing such as a fitting, hose, or compressor/condensor.

When you notice a loss of cooling it always is a repair. Adding refigerant alone never cures the problem, it just masks it for a short while.
Barry45RPM is offline  
Old 04-14-2008, 12:34 PM
Out Of Control!!
konigstiger's Avatar
Join Date: Jul 2003
Location: North Scottsdale, AZ
Posts: 10,384
Received 1,164 Likes on 980 Posts
'71 Pinto
Originally Posted by MB500 View Post
In the last couple of days it has been extremely hot in Southern California and I noticed that my air conditioning wasn't delivering as much of cold air as it used to.
Note during rapid acceleration, heavy braking, and high speeds the compressor output is lowered to provide the engine with extra power. If these situations are not associated with your complaint, then the cause may be a malfunctioning humidity sensor (part #A2118300572) or low refrigerant level in which case the refrigeration system needs to be checked for leakage using fluorescent dye.


VIN A845370 to B100720 and X189946 to X223159

If you are experiencing reduced airflow and cooling after driving for a while, the cause may be the evaporator has become frozen. Under certain temperature, humidity and driving conditions evaporator temperature control may not be optimized since the deletion of the humidity sensor starting with 7/05 production - you will see a blank plug in place of the sensor shown. Mention DTB P-B-83.00/102 MAY07 and dealer will install a humidity sensor.
Attached Thumbnails E500 A/C Question-humidity_sensor.jpg  

Last edited by konigstiger; 04-14-2008 at 12:38 PM.
konigstiger is offline  
Old 04-14-2008, 12:54 PM
MBWorld Fanatic!
ohlord's Avatar
Join Date: Apr 2007
Posts: 6,170
Likes: 0
Received 4 Likes on 4 Posts
300E a couple 1994 w124wagon E320 Wagon/,1971MGB Track/Rally, MG Midget Autocross ,2000 E320 wagon.

you 211 guys have onboard diagnostics for the climate control?
if you do,run the tests and errors and see what you come up with.
Autozones usually carry the dye kit and rent a uv light.Or you can get the more accurate electronic sniffer at harbor freight tools.However if you are not use to working with a/c it may be best to run the tests if your system has them and take the results to a good a/c shop.Dye is messy,you need to evacuate,vacuum ,and install a new drier and recharge the system with r134a and the proper amount of a/c oil.If you know how to do all that and have the tools you probably would not be asking the question
ohlord is offline  
Old 08-09-2014, 08:08 PM
Join Date: Jan 2014
Posts: 3
Likes: 0
Received 0 Likes on 0 Posts
03 E500 Sport
ac problem

Hi everyone been hectic evening today bcus my ac stopped working on my 03 E500. I noticed fuse in driver side box blown so as anyone else would I replaced it. As soon as I plugged it in it blew. Im new to MB and the forum but can anyone give up some ideas of things to try on fixing myself it would b appreciated?
jayzE500 is offline  
Old 08-09-2014, 08:39 PM
Out Of Control!!
Join Date: Feb 2011
Location: Tampa
Posts: 11,919
Received 590 Likes on 573 Posts
1999 E300TD
Check you fuse listing card on the flap of the under hood fuse box!!
Plutoe is offline  
Old 08-09-2014, 08:44 PM
Join Date: Jan 2014
Posts: 3
Likes: 0
Received 0 Likes on 0 Posts
03 E500 Sport
Thank you I will in little while. .... just coming home from work and require a hot shower. Hopefully its a easy fix and not to costly.
jayzE500 is offline  
Old 08-10-2014, 08:18 AM
MBWorld Fanatic!
vettdvr's Avatar
Join Date: Mar 2006
Location: Louisiana
Posts: 3,254
Likes: 0
Received 4 Likes on 4 Posts
03 E500 and Corvette
Most a/c systems that are not totally enclosed such as a refrigerator use a mechanical seal. Some are carbon disc with ceramic disc. They wear in and seal very well in modern car a/c. They do however leak, granted it may be small and you may not detect it but they can leak up to 2 oz/yr and be considered still good for service.

What this means you might be leaking UP TO 2 oz/yr with a normal system and a car 10 yrs old never serviced "might" have leaked up to 20 oz. Granted it would quit working before then. A car 10 yrs old that has never been checked or added Freon could still be low and still working. My guess it a 10 yr old car would just need a top off of perhaps 5 to 10 oz to return it back to full charge.

However many shops will tell you low on Freon, have to find leak, discharge pull vacuum and charge fully then inspect. With a normal wearing seal you probably won' t need all the extras and only have 'normal' seal leakage, but that is the only way a shop could put their name on it as being "right" for and service they preform.
vettdvr is offline  
Old 08-10-2014, 09:10 AM
Join Date: Jan 2014
Posts: 3
Likes: 0
Received 0 Likes on 0 Posts
03 E500 Sport
Unfortunately no type of had 3 previous wondering in compressor is lock and if thats y fuse is blowing
jayzE500 is offline  

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)

Thread Tools
Search this Thread
Rate This Thread
Rate This Thread:
You have already rated this thread Rating: Thread Rating: 0 votes,  average.

Quick Reply: E500 A/C Question

Contact Us - About Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to and affiliated sites.
  • Ask a Question
    Get answers from community experts
Question Title:
Your question will be posted in: