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 > Tech Help

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 11-14-2010, 10:23 AM
land sea air's Avatar
HAHA THAT'S WHAT SHE SAID
 
Join Date: Oct 2005
Location: Gaithersburg Maryland
Posts: 201
86' 500SE, replaced both monovalves and still no heat

Here's a riddle hopefully you guys can help me solve. my 500SE has never had heat from the main air vents since I had the car and I always suspected the monovalves (for some reason if I closed all the main vents I could get a decent flow of hot air through the small upper vents on the end. Between that and heated seats I never got cold enough to check it) I recently replaced the radiator and while I was at it I replaced both valves since the car is dual zone. Sure enough both old valves were completely destroyed so I figured it was solved however I still have no heat. The only thing I can think of is there is still a lot of air in the system since it was partially drained for the radiator and the valve box was empty by the time I pulled the lid off. Is there a way to bleed the system or could something more sinister be the cause?

__________________
E30 B25
126.036
123.130 with 616-Frankenbenz (sold)
124.030-Greyhound (sold)
124.030-Schnauzer (sold)


DERP DERP
Reply With Quote
  #2  
Old 11-15-2010, 08:40 AM
Moderator
 
Join Date: Mar 1999
Location: Tucker, Ga USA
Posts: 12,153
If you unplug the valve assembly, you should get very hot air from the side vents & defrost.

Center vent is not designed to allow for hot air.
__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator
Reply With Quote
  #3  
Old 11-15-2010, 08:49 AM
land sea air's Avatar
HAHA THAT'S WHAT SHE SAID
 
Join Date: Oct 2005
Location: Gaithersburg Maryland
Posts: 201
the vents in the middle of the dash are not designed to allow for hot air? Is that something euro specific?
__________________
E30 B25
126.036
123.130 with 616-Frankenbenz (sold)
124.030-Greyhound (sold)
124.030-Schnauzer (sold)


DERP DERP
Reply With Quote
  #4  
Old 11-15-2010, 08:59 AM
mommamia
 
Join Date: Dec 2007
Location: Maryland
Posts: 508
No. The center vents are designed to blow cool/cold air. When your AC is running or using climate control cool/cold air will come out of the center vents to maintain proper cabin temperature.
__________________
1995 E420 152k
1991 300D 2.5 348116 daily driver
1992 300E 2.6 196k-work in progress(head gasket)
2002 BMW 745Li 93k
Reply With Quote
  #5  
Old 11-15-2010, 09:00 AM
land sea air's Avatar
HAHA THAT'S WHAT SHE SAID
 
Join Date: Oct 2005
Location: Gaithersburg Maryland
Posts: 201
this is unlike any other MB I've ever owned, I was under the impression that with the heat on there would be warm air out of all the vents...
__________________
E30 B25
126.036
123.130 with 616-Frankenbenz (sold)
124.030-Greyhound (sold)
124.030-Schnauzer (sold)


DERP DERP
Reply With Quote
  #6  
Old 11-15-2010, 09:06 AM
mommamia
 
Join Date: Dec 2007
Location: Maryland
Posts: 508
That would be incorrect. It ffunctions the same way on my '91and '92 124's.
__________________
1995 E420 152k
1991 300D 2.5 348116 daily driver
1992 300E 2.6 196k-work in progress(head gasket)
2002 BMW 745Li 93k
Reply With Quote
  #7  
Old 11-15-2010, 09:08 AM
land sea air's Avatar
HAHA THAT'S WHAT SHE SAID
 
Join Date: Oct 2005
Location: Gaithersburg Maryland
Posts: 201
I'm not saying you're wrong, but my 87 and 88 300Es and 78 240D blew hot from all vents with the heat on. I will unplug the connector from the valve assembly when I get home and see if heat comes out of the other vents.
__________________
E30 B25
126.036
123.130 with 616-Frankenbenz (sold)
124.030-Greyhound (sold)
124.030-Schnauzer (sold)


DERP DERP
Reply With Quote
  #8  
Old 11-15-2010, 09:18 AM
mommamia
 
Join Date: Dec 2007
Location: Maryland
Posts: 508
I've been wrong before...lol. Although I'm pretty certain about this problem.
__________________
1995 E420 152k
1991 300D 2.5 348116 daily driver
1992 300E 2.6 196k-work in progress(head gasket)
2002 BMW 745Li 93k
Reply With Quote
  #9  
Old 11-15-2010, 09:30 AM
vabenz
 
Join Date: Jun 2008
Location: White Stone, VA
Posts: 25
dablk1 is correct, the center vents are closed off when heat is on to force flow to the floor vents. Failed actuator(s) at flaps allows the heat to blow thru the center vents. A PITA to repair so many just live with hot face and cold feet.
I would suspect a thorough bleed of coolant circuits will reawaken the heat. Warm car, turn heat to max and add coolant as needed. Takes a bit of time but the system will self bleed.
Reply With Quote
  #10  
Old 11-15-2010, 09:33 AM
land sea air's Avatar
HAHA THAT'S WHAT SHE SAID
 
Join Date: Oct 2005
Location: Gaithersburg Maryland
Posts: 201
just to be clear, this is a euro spec model with a separate dial to control where the air goes to, and one to control fan speed instead of the usual push button system. The vents are controlled by sliders to shut them off.
__________________
E30 B25
126.036
123.130 with 616-Frankenbenz (sold)
124.030-Greyhound (sold)
124.030-Schnauzer (sold)


DERP DERP
Reply With Quote
  #11  
Old 11-15-2010, 10:04 AM
Moderator
 
Join Date: Mar 1999
Location: Tucker, Ga USA
Posts: 12,153
On a W126 the center vent was not designed for heated air.
__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator
Reply With Quote
  #12  
Old 11-16-2010, 08:20 AM
land sea air's Avatar
HAHA THAT'S WHAT SHE SAID
 
Join Date: Oct 2005
Location: Gaithersburg Maryland
Posts: 201
tried the heat again today, the only vents that get any heat are the upper end vents, the ones that are mostly for defrost, I do not feel any heat from the main end vents or from the main defrost. I don't think there's any air left in the system either since the coolant has leveled off. The knob to adjust which vents output air doesn't seem to be changing anything but I figure there should still be heat coming from somewhere...

__________________
E30 B25
126.036
123.130 with 616-Frankenbenz (sold)
124.030-Greyhound (sold)
124.030-Schnauzer (sold)


DERP DERP
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 01:51 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2021, 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