Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help




Go Back   PeachParts Mercedes-Benz Forum > Mercedes-Benz Tech Information and Support > Diesel Discussion

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 08-26-2008, 10:53 PM
Registered User
 
Join Date: Apr 2001
Location: So. California
Posts: 744
Our 123/126 A/C systems take too long to cool down, why

Hi guys,

Looking to start a discussion about the length of time it takes the A/C to start blowing cold cold cold....blah.......

From an engineering standpoint, why does the wife's '02 Explorer start blowing cold almost immediately and both of my 123's have taken some street time to start blowing cold (cold like you know you're on the right track)? It can't be the 134 vs R12 debate. The Ford runs R134....so I'm throwing it out there. And just for the record, my 123 will blow 35F on Freeze 12, just takes awhile to get there. Yeah I know the system is 25yo and the evaporator is probably dirty. What else?

i think these car's A/C systems have not been their strong point. Flame on kids:
__________________
84 300DT Puke Yellow. Totalled after 438,000
84 300DT Orient Red. 169,000 (actual mileage may vary)
2002 Explorer EB (wife's)
Reply With Quote
  #2  
Old 08-26-2008, 11:29 PM
Registered User
 
Join Date: Oct 2005
Posts: 4,263
The AC system was not your car's strong point.

The W210 factory 134a system starts cooling nearly instantly.
Reply With Quote
  #3  
Old 08-26-2008, 11:54 PM
bustedbenz's Avatar
Registered User
 
Join Date: Feb 2007
Location: Lexington, NC or Boone, NC
Posts: 2,270
Quote:
Originally Posted by Eric Eliel View Post
Hi guys,
It can't be the 134 vs R12 debate. The Ford runs R134....
It's not the refrigerant necessarily, but simply the systems themselves. The Ford system was designed to be large enough to do the job plus a little extra. It's simply a higher capacity cooling apparatus.

The apparatus they put on the Mercedes, for whatever reason, is simply trying to do a job bigger than it's capable of, due to being designed to a less stringent requirement than that which we'd prefer it to be fulfilling.
__________________


http://www.appstate.edu/~salleyms

"What could possibly go wrong?"

~Michael S.~ -
1986 M-B 300SDL, retired due to rust and electrical problems. Donated engine to:
1987 M-B 300SDL, odo dead. New project.
1982 M-B 240D, odo stopped at 308,000
1982 M-B 300SD, 175,000
1989 Dodge Ramcharger, 87,000 - 4wd, 318
Reply With Quote
  #4  
Old 08-27-2008, 12:16 AM
compress ignite's Avatar
Drone aspiring to Serfdom
 
Join Date: Feb 2004
Location: 32(degrees) North by 81(degrees) West
Posts: 5,554
I.e.

Ask any German driver if Frostbite type A/C is/was ever at the top of His/Her list
of most important attributes for an automobile.

Wasn't until somebody dragged somebody else (maybe Werner Von Braun was the dragee) out to Death valley at Summers height that word filtered back to
Deutschland that a refrigeration system would be appropriate in a luxury Auto.

RANT: You can,with a little effort,have your MB deliver Frosty Air Instantly...
1.Parallel Flow Condenser (As Large As YOU can STUFF in front of the Radiator).
2.NEW (NOT REMAN) High capacity Compressor.
3.Clean,Clean,Clean:Evaporator,Condenser ,RADIATOR,System Hoses,Etc.
4.Nylog for the New O-Rings.
5.NEW SEALED Receiver/Dryer.
6.Vacuum Overnight.'Holds vacuum? Then:
7.Pressure test with Nitrogen. O.K.? Then:
8.Re-Vacuum after Nitrogen is out.
9.Fill with the proper amount of R-12 and Lubricant.
10. Make sure you have "Long Johns (or Janes)" on.
__________________
'84 300SD sold
124.128

Last edited by compress ignite; 08-27-2008 at 12:27 AM.
Reply With Quote
  #5  
Old 08-27-2008, 12:23 AM
TylerH860's Avatar
KHAAAAAAN-gress
 
Join Date: Aug 2007
Location: Wichita, Ks
Posts: 5,187
I've always found my AC to be adequate.
__________________
1985 500SL Euro w/ AMG bits 130k
1984 300SD Turbodiesel 192k
1980 240D Stick China 188k
2001 CLK55 AMG 101k
2007 S600 Biturbo 149k Overheated Project, IT'S ALIVE!!!
Reply With Quote
  #6  
Old 08-27-2008, 12:39 AM
JimmyL's Avatar
Rogue T Intolerant!!!
 
Join Date: May 2004
Location: Sunnyvale, Texas (DFW)
Posts: 9,673
I can start my F150 out in the driveway, leave it sitting there, come back in 5-10 minutes and the cab is freezing. {with temps in 90's or 100s}
Drive the Mercedes home, start with the interior cold, leave it sitting in the driveway and in 5 minutes it's up over 60 degrees. That is all of them with each type of refrigerant.
Condenser and evap are simply inadequate......
__________________
Jimmy L.
'05 Acura TL 6MT
2001 ML430 My Spare

Gone:
'95 E300 188K "Batmobile" Texas Unfriendly Black
'85 300TD 235K "The Wagon" Texas Friendly White
'80 240D 154K "China" Scar engine installed
'81 300TD 240K "Smash"
'80 240D 230K "The Squash"
'81 240D 293K"Scar" Rear ended harder than Elton John
Reply With Quote
  #7  
Old 08-27-2008, 12:54 AM
Registered User
 
Join Date: Apr 2003
Location: Phoenix Arizona. Ex Durban R.S.A.
Posts: 3,432
Hmmm. So then along the lines of Compressignite's post above it should be possible to retrofit almost any Mercedes from a Ponton on down with a custom A/C system that really will live up to the requirements of life in oh, say, Phoenix AZ for example.

- Peter.
__________________
81 240D stick. 316000 miles at purchase. 342000 now
2000 GMC Sonoma
Formerly...
2002 Kia Rio. Worst crap on four wheels
1981 240D 4spd stick. 389000 miles. Deceased Jan 08
1984 123 200
1979 116 280S
1972 Cadillac Sedan DeVille
1971 108 280S
Reply With Quote
  #8  
Old 08-27-2008, 01:02 AM
Registered User
 
Join Date: Oct 2005
Posts: 4,263
Quote:
Originally Posted by pj67coll View Post
Hmmm. So then along the lines of Compressignite's post above it should be possible to retrofit almost any Mercedes from a Ponton on down with a custom A/C system that really will live up to the requirements of life in oh, say, Phoenix AZ for example.

- Peter.
Of course it is possible. That doesn't mean that it will be inexpensive.
Reply With Quote
  #9  
Old 08-27-2008, 01:13 AM
bustedbenz's Avatar
Registered User
 
Join Date: Feb 2007
Location: Lexington, NC or Boone, NC
Posts: 2,270
Exactly. I have always found mine woefully inadequate but I have too many other places my money needs to stretch to.
__________________


http://www.appstate.edu/~salleyms

"What could possibly go wrong?"

~Michael S.~ -
1986 M-B 300SDL, retired due to rust and electrical problems. Donated engine to:
1987 M-B 300SDL, odo dead. New project.
1982 M-B 240D, odo stopped at 308,000
1982 M-B 300SD, 175,000
1989 Dodge Ramcharger, 87,000 - 4wd, 318
Reply With Quote
  #10  
Old 08-27-2008, 02:46 AM
Registered User
 
Join Date: Apr 2001
Location: So. California
Posts: 744
The window tint on the back half of the car helped. The dark Orient Red paint in the summer doesn't help.
__________________
84 300DT Puke Yellow. Totalled after 438,000
84 300DT Orient Red. 169,000 (actual mileage may vary)
2002 Explorer EB (wife's)
Reply With Quote
  #11  
Old 08-27-2008, 03:25 AM
compu_85's Avatar
Waiting for his Model 3..
 
Join Date: May 2008
Location: Springfield VA
Posts: 5,174
The AC on mine is great when moving. When stopped the temp creeps up to 60*F on hot days. No, it's not the rad fan(s), both electric ones work and the belt fan is new.

The system in my 99.5 TDI (which got a new $900 compressor in 2005) blows only slightly colder. The big difference is at idle. When underway there is almost no difference. The Benz does seem to cool the interior quicker. Perhaps because the dash is 1/2 the size?

-Jason
__________________
1991 350SDL. 230,000 miles (new motor @ 150,000).

2013 Fiat 500E. 20,000 miles, 80 miles at a time.
2012 Passat TDI. 95,000 miles. More space, power, and fuel economy than the Benz
2004 Touareg V10 TDI. 150,000 miles. One of 450.
1999 Jetta TDI. 310,000 miles.
1992 Jetta ECOdiesel. 156,000 miles. 1 of 48. Sold.
1991 Jetta ECOdiesel. 430,000 miles. 1 of 700. Sold to VeeDubTDI, totaled in front of our house

Last edited by compu_85; 08-27-2008 at 04:03 AM.
Reply With Quote
  #12  
Old 08-27-2008, 09:29 AM
vstech's Avatar
DD MOD, HVAC,MCP,Mac,GMAC
 
Join Date: Mar 2006
Location: Mount Holly, NC
Posts: 26,247
Quote:
Originally Posted by compress ignite View Post
Ask any German driver if Frostbite type A/C is/was ever at the top of His/Her list
of most important attributes for an automobile.

Wasn't until somebody dragged somebody else (maybe Werner Von Braun was the dragee) out to Death valley at Summers height that word filtered back to
Deutschland that a refrigeration system would be appropriate in a luxury Auto.

RANT: You can,with a little effort,have your MB deliver Frosty Air Instantly...
1.Parallel Flow Condenser (As Large As YOU can STUFF in front of the Radiator).
2.NEW (NOT REMAN) High capacity Compressor.
3.Clean,Clean,Clean:Evaporator,Condenser ,RADIATOR,System Hoses,Etc.
4.Nylog for the New O-Rings.
5.NEW SEALED Receiver/Dryer.
6.Vacuum Overnight.'Holds vacuum? Then:
7.Pressure test with Nitrogen. O.K.? Then:
8.Re-Vacuum after Nitrogen is out.
9.Fill with the proper amount of R-12 and Lubricant.
10. Make sure you have "Long Johns (or Janes)" on.
NEVER! I repeat NEVER test a system with vacuum... test with nitrogen FIRST!!!!!
if you test with vacuum, and it does not hold you have just ruined your drier!
look. think learn!
testing with vacuum is stupid stupid stupid.
it's only at most 14.7 psi differential from atmospheric pressure.
a HUGE leak will not show up with vacuum on a crappy charging manifold.
IF IF IF IF IF IF IF you have a DIGITAL micron gauge, AND AND AND you have experience with charging rates and vacuum rates of drop, you can get a feel for a tight system, BUT nitrogen is WAAAAAAAAAAY safer and easier to test for a leak.
PLEASE get it through your heads. DO NOT TEST FOR LEAKS WITH VACUUM!@!!!!!!
__________________
John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!
Reply With Quote
  #13  
Old 08-27-2008, 03:25 PM
Registered User
 
Join Date: Apr 2001
Location: So. California
Posts: 744
Anyone want to develop a 2 to 3 minute timed electrical relay that would automatically turn the aux fan on when the A/C is turned on? Kinda of like jump starting the A/C cooling process.

Think this would help?
__________________
84 300DT Puke Yellow. Totalled after 438,000
84 300DT Orient Red. 169,000 (actual mileage may vary)
2002 Explorer EB (wife's)
Reply With Quote
  #14  
Old 08-27-2008, 03:37 PM
Registered User
 
Join Date: Oct 2005
Posts: 4,263
I don't think it would help. Instead, insure that your refrigerant pressure and temperature sensors are working, and start the fan when appropriate.
Reply With Quote
  #15  
Old 08-27-2008, 03:52 PM
Registered User
 
Join Date: Apr 2001
Location: So. California
Posts: 744
Quote:
Originally Posted by Matt L View Post
and start the fan when appropriate.
Huh? The electrical fan in front of the radiator starts on its own when the temperature switch is triggered by the heat sensor in the receiver/dryer. You can't turn it on manually. My idea would be to design a circuit that would starting the condensor fan cooling process immediately but temporarily to get the condensor cooling faster.
__________________
84 300DT Puke Yellow. Totalled after 438,000
84 300DT Orient Red. 169,000 (actual mileage may vary)
2002 Explorer EB (wife's)
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not 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 On
Trackbacks are On
Pingbacks are On
Refbacks are On




All times are GMT -4. The time now is 05:17 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page