A/C Stops Working while driving - Thoughts, Ideas? - Mercedes Benz SLK Forum
SLK R171 General Discussion SLK 200, SLK 280, SLK 300, SLK 350, SLK 55 AMG

Reply
 
LinkBack Thread Tools
#1 Old 06-14-2010
SLK World Member
 
Join Date: Jun 2009
Location: Tampa Florida
Vehicle: 2006 SLK350 Pewter Ext., Black Int., Auto
Posts: 48
Country:
Chats: 0
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 17 Times in 8 Posts
(Thread Starter)
A/C Stops Working while driving - Thoughts, Ideas?

We have a 2006 SLK350 about 54,000 miles - auto, been pretty much problem free. However past 6-8 months a/c will stop working while driving, just turns off while driving. A/C button light is on - but cold air stops blowing and warm/hot air (like just open vents) blow in. This has happend 3 times in the past 6-8 months. Tried turning it off/on (pressing a/c button), pressing Auto button on climate control, changing temp, nothing works (meaning a/c getting cold again), only thing that seems to work is turning car off and then turn it back on, a/c then comes on fine (blows cold again). A/c is ice cold.

Not sure if anyone has had a similar problem or ideas on what it might be.

Its is starting to get hot in Florida. Going to dealer on Friday for B Service, but if had any thoughts about potential issue could share with dealer. Thanks.
firstmercedes is offline  
Sponsored Links
Advertisement
 
#2 Old 06-14-2010
aka John

 
UK-C200's Avatar
 
Join Date: May 2008
Location: Richmond, Tx
Vehicle: LHD Black SLK350, LHD Firemist SLK55
Other Toys: Nacra F18
Posts: 12,998
Country:
Chats: 1143
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 8 Post(s)
Thanks: 1,704
Thanked 2,889 Times in 2,016 Posts
When this happens - does it sound like the fan is still blowing, just no air coming out of the vents?




Life is good - enjoy it with the top down!



To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
UK-C200 is offline  
#3 Old 06-14-2010
SLK World Member
 
Join Date: Jun 2009
Location: Tampa Florida
Vehicle: 2006 SLK350 Pewter Ext., Black Int., Auto
Posts: 48
Country:
Chats: 0
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 17 Times in 8 Posts
(Thread Starter)
The fan (blower) works fine, air still comes out and adjusts with the different speed selections on the dial.
firstmercedes is offline  
#4 Old 06-14-2010
aka John

 
UK-C200's Avatar
 
Join Date: May 2008
Location: Richmond, Tx
Vehicle: LHD Black SLK350, LHD Firemist SLK55
Other Toys: Nacra F18
Posts: 12,998
Country:
Chats: 1143
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 8 Post(s)
Thanks: 1,704
Thanked 2,889 Times in 2,016 Posts
Weird - I've heard os a failure mode where the vents all close, but not one where the A/C completely cuts out and does not come back...

Be interesting so see what codes (if any?!) are stored.




Life is good - enjoy it with the top down!



To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
UK-C200 is offline  
#5 Old 06-15-2010
aka Denny
 
carver's Avatar
 
Join Date: Jun 2008
Location: Denver, Colorado - USA
Vehicle: 2008 SLK 350
Other Toys: 2011 E550
Posts: 196
Country:
Chats: 3
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 55
Thanked 50 Times in 26 Posts
Any chance you are using air recirculation mode on those hot days? This doesn't exactly sound like your issue but I thought I point it out just in case. In air recirculation mode the car will automatically pull in outside air every 30 minutes or so. On a really hot day it may feel like the AC has quit working.

This doesn't exactly align with what you've described, but I've seen other similar posts where people didn't know the car behaved this way. If you are using air recirculation mode, perhaps it is switching to outside air and never resetting until you shut off and restart the car. Just a guess - could be way off.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
carver is offline  
#6 Old 06-15-2010
Banned
 
Join Date: Nov 2009
Location: Dayton, OH
Vehicle: '09 SLK 350
Other Toys: RC Model Planes, '06 MX-5
Posts: 147
Country:
Chats: 0
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 1
Thanked 12 Times in 10 Posts
When you don't get any cold air, the compressor has stopped working. I'm assuming that the system doesn't have any leaks and has freon. This seems to be the case, since you can get cold air after stoping and restarting.

You should familiarize yourself with the fundamentals of the system. The evaporator is inside the car and the compressor & condenser are in the engine compartment. What I believe your problem is a solenoid that is thermostatically controlled that turns the compressor on and off.

Also you might let the car idle with the system on and stick a thermometer in one of the vents. If the temperature is reasonably cold, you know the heart of the system is OK, and your problem is as I described. Incidentally, the freon level can be checked by looking at a sight gauge.

A/C repairs can be horrendously expensive. I'd shop around for an independent who is good at diagnostic work. Anyway, your problem sounds electrical and shouldn't be too expensive. BTW, always check out a shop with the BBB. Even the state's AG if possible.
VivreBien is offline  
#7 Old 06-15-2010
Founding Member #2

 
etyu's Avatar
 
Join Date: Jun 2006
Location: Orange County, CA
Vehicle: 2008 SLK 55
Posts: 17,832
Country:
Chats: 11
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 12 Post(s)
Thanks: 4,411
Thanked 2,862 Times in 2,065 Posts
Garage
Just relating some personal experience:

This is on my daughter's 10+ year old BMW E46. The a/c system (with auto mode) would spew out hot air (almost thinking like it was on defrost mode, and the fan speed would increase) while driving and would remain so for almost one hour until turned off manually. Cold air would return after maybe 2 hours of being turned off. This would recur again almost 1-2X/day.

BMW service did a test on the system and found that the baseline pressure was fine but on turning on the compressor, it failed to reach the target pressure. Technician added more refrigerant with fluorescein dye to detect leaks. Very little or minimal dye noted along the tubes and junctions. Since the addition of the refrigerant, the A/C did the hot air thing for once or twice and then everything has been working fine for the last 4 months.

BMW did not charge and service advisor left the job order "open" so it can be revisited anytime later.

Eddy



To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

Pewter(cubanitsilber metallic)/Beige, PIII package, Airscarf, Hands-Free Communication System, Lighting package; Designo Black Leather Cover on e-brake handle(Thank you Bill T), SmartTop v3.x, John's 3BFM, M113 AMG OEM air filters, Modified R170 ant., clear side-markers & front parking lamps w/error-free LEDs, chromed front & rear turn indicator lamps, steel mesh at battery bay cover & cabin air intake, sock-over-seatbelt buckles, belt-loop guide protectors, Lamin-X fog lamp protectors, bilateral rear fog lamps enabled, etched ///AMG logo on gear shift knob by Blackrose-etching
etyu is offline  
#8 Old 06-16-2010
SLK World Member
 
Join Date: Jun 2009
Location: Tampa Florida
Vehicle: 2006 SLK350 Pewter Ext., Black Int., Auto
Posts: 48
Country:
Chats: 0
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 17 Times in 8 Posts
(Thread Starter)
Thanks for the ideas. I also thought it might be something electronic since the a/c is ice cold and it only happened a couple times in the past 6-8 months. It is going in for a B Service Friday, I will ask the dealer how much to diagnosis.
firstmercedes is offline  
#9 Old 06-16-2010
SLK World Junior Member
 
Join Date: Jun 2010
Location: Arkansas
Vehicle: 2006 SLK 350
Posts: 3
Country:
Chats: 0
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
My wife's '06 SLK 350 is in the shop right now for the exact same problem. Turns out it's something electrical (relay?) in the compressor. It threw a code, so the dealer should be able to track it down.
TheSlacker is offline  
#10 Old 06-16-2010
aka John

 
UK-C200's Avatar
 
Join Date: May 2008
Location: Richmond, Tx
Vehicle: LHD Black SLK350, LHD Firemist SLK55
Other Toys: Nacra F18
Posts: 12,998
Country:
Chats: 1143
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 8 Post(s)
Thanks: 1,704
Thanked 2,889 Times in 2,016 Posts
Awesome - please let us know what they come up with!!!




Life is good - enjoy it with the top down!



To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
UK-C200 is offline  
#11 Old 06-17-2010
SLK World Member
 
Join Date: Jun 2009
Location: Tampa Florida
Vehicle: 2006 SLK350 Pewter Ext., Black Int., Auto
Posts: 48
Country:
Chats: 0
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 17 Times in 8 Posts
(Thread Starter)
This is why this forum is so great, sharing!
firstmercedes is offline  
#12 Old 10-30-2010
SLK World Junior Member
 
Join Date: Jun 2010
Location: Boca Raton
Vehicle: 2005 SLK55, Silver, 19" HRE Wheels
Posts: 2
Country:
Chats: 0
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
Slk55 2005

I have the same problem with A/C, if I drive on the interstate for longer than 1 hour to 1 hour and 15 minutes, my air actually almost all stops coming out! At first on a real long trip and hot day to the keys, I had the AC pumping at 60 degrees, and it started dripping water on my driver side carpet ! Since then I changed the degrees in my car to 72 degrees, no more water dripping, but now after 1 hour to 1 hour and a half, the air feels very restricted coming out and you can barely feel it, and the air is warm. I turn it off on the drive for about 30 minutes, and then restart and it works again and just repeats problem.

On less than hour trips, the air works great, what is my problem ? I dont want to go to mercedes benz and them say something needs replaced, that truly does not !

Please help, thanks

Last edited by ridgway767; 10-30-2010 at 10:59 AM. Reason: wanted to put kind of car I have
ridgway767 is offline  
#13 Old 10-30-2010
SLK World Junior Member
 
Join Date: Jun 2010
Location: Boca Raton
Vehicle: 2005 SLK55, Silver, 19" HRE Wheels
Posts: 2
Country:
Chats: 0
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
ALSO what should I truly expect on a Service B maintenance ? I have a private guy who used to work at MB, now runs a private shop for MB service, charging $200, oil and check systems, he also is saying since my car should have transmission flush service every 40,000, I have 80,000 miles now on it. he wants an additional 180$ for that service, is this reasonable ? What else is needed at 80,000 miles ?? When I brake at high speeds my car shakes, I was told rotors are warped, which are insanely expensive, any ideas on a good place to buy rotors, and if shaking at 40 mph plus, is it my front rotors right ? Sorry for so many questions !!
ridgway767 is offline  
#14 Old 10-30-2010
Registered Users
 
piperkid's Avatar
 
Join Date: Apr 2009
Location: Glendale, Arizona
Vehicle: 2007 SLK350
Other Toys: Commander, Turbo Airplane, BMW Z3, C5 Vette, Honda VTX 1800 MC
Posts: 82
Country:
Chats: 0
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 1
Thanked 11 Times in 11 Posts
Rotors not that expensive from aftermarket sources. Here are a bunch for under $100 each.

http://www.rockauto.com
piperkid is offline  
#15 Old 02-20-2011
SLK World Junior Member
 
Join Date: Nov 2009
Posts: 6
Country:
Chats: 0
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
I also have the exact same problem.
magiccar is offline  
#16 Old 04-27-2011
SLK World
 
Join Date: Jan 2009
Location: PA
Vehicle: 05 SLK 350
Other Toys: X3, Yamaha R1, 93 Nissan Pickup(Need something for firewood)
Posts: 55
Country:
Chats: 0
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 6
Thanked 4 Times in 3 Posts
Hello I'm having the same problem as well on my 05 350 after around a half hour the AC barely blows any air out of the vents and you can hear the Blower motor spinning.
Even at full blast there is barely any air coming out.

Before the 1/2 hour mark the AC is freezing my wife even complains that it's way too cold on a hot day so it’s working great for a blast around town.

But on my hour commute it shuts down about half way there.

If I shut off the car for a bit and start it back up the AC works fine again.

I would take it to the dealer but it seems like any easy fix since the system is actually producing cold air for the half hour when it works.

I thought maybe the car was overheating and cutting off but it stays pretty much at 85-90C on a hot summer day.

Thanks for any help!



caraddict is offline  
#17 Old 04-27-2011
aka John

 
UK-C200's Avatar
 
Join Date: May 2008
Location: Richmond, Tx
Vehicle: LHD Black SLK350, LHD Firemist SLK55
Other Toys: Nacra F18
Posts: 12,998
Country:
Chats: 1143
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 8 Post(s)
Thanks: 1,704
Thanked 2,889 Times in 2,016 Posts
Quote:
Originally Posted by caraddict View Post
Hello I'm having the same problem as well on my 05 350 after around a half hour the AC barely blows any air out of the vents and you can hear the Blower motor spinning.
Even at full blast there is barely any air coming out.

Before the 1/2 hour mark the AC is freezing my wife even complains that it's way too cold on a hot day so it’s working great for a blast around town.

But on my hour commute it shuts down about half way there.

If I shut off the car for a bit and start it back up the AC works fine again.

I would take it to the dealer but it seems like any easy fix since the system is actually producing cold air for the half hour when it works.

I thought maybe the car was overheating and cutting off but it stays pretty much at 85-90C on a hot summer day.

Thanks for any help!


Caraddict - I don't think there's a 100% diagnoses, but it seems that your system is going into "exchange" mode, where is switches to pulling air in from the outside of the car vs recirculation, and then not popping out of that mode.

I would suspect if that was the case the controller would be storing some errors - your dealer sees no stored errors?




Life is good - enjoy it with the top down!



To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
UK-C200 is offline  
#18 Old 04-27-2011
SLK World
 
Join Date: Jan 2009
Location: PA
Vehicle: 05 SLK 350
Other Toys: X3, Yamaha R1, 93 Nissan Pickup(Need something for firewood)
Posts: 55
Country:
Chats: 0
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 6
Thanked 4 Times in 3 Posts
I'll have to take another look for codes but I did not see any when I scanned and replaced a bad coil pack last summer while this problem was occurring.

I typically avoid dealers if I can help it I like performing all of my own repairs.
MB dealers do seem better than my experience with BMW which I why I left that brand forever!
It's a shame I loved my M but there isn't a good BMW dealer within 100 miles of me.


caraddict is offline  
#19 Old 04-27-2011
Banned
 
Join Date: Mar 2011
Posts: 7,812
Country:
Chats: 0
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 681
Thanked 952 Times in 699 Posts
That intermittent loss of cold could be the refrigerant becoming low when the compressor kicks in. ( Just a thought ) The compressor is shut down if it falls below a certain level. Mine did and even regassing didnt cure it as the system stores the fault. It was only cured this morning after the faults were cleared. Cant understand why the system cant reset itself once the gas is back up to correct pressure
JonB is offline  
#20 Old 11-21-2012
Registered Users
 
Join Date: Jul 2010
Location: Friendswood, TX
Vehicle: 07 280 SLK
Posts: 174
Country:
Chats: 0
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 31
Thanked 24 Times in 19 Posts
Did we ever learn the problem and fix related to the opening post? I have the same issue.
jfpslk is offline  
The Following User Says Thank You to jfpslk For This Useful Post:
Sponsored Links
Advertisement
 
Reply

  Lower Navigation
Go Back   Mercedes Benz SLK Forum > Mercedes Benz R171 SLK Class Cars > SLK R171 General Discussion

Bookmarks

Quick Reply
Message:
Options
Upload your files to MEGAUPLOAD
Upload your images to ImageShack

Register Now

In order to be able to post messages on the Mercedes Benz SLK Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




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

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Similar Threads
Thread Thread Starter Forum Replies Last Post
A/c on/off steve-p SLK R171 General Discussion 18 04-18-2007 08:18 PM
Heated rear screen not working, any ideas? aquascape SLK R171 General Discussion 2 11-03-2006 04:46 PM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome