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 ShopForum > Technical Information and Support > Tech Help

LinkBack Thread Tools Display Modes
Old 01-16-2000, 05:13 PM
James Stephens
Posts: n/a
My 1988 300SEL has a heater problem. It will intermittently work at the MAX setting. When the car reaches operating temperature and the Climate control is in the MAX position the heater works sometimes. When the dial is then moved into the white normal operating zone it blows cold air. When I move the dial back to MAX it still blows cold air. I can then turn the engine off, immediately restart it and the heater will again work on the MAX setting. What can be the problem here. Any help is greatly appreciated. Thanks in advance.

James Stephens
Reply With Quote
Old 01-17-2000, 07:36 PM
Join Date: Mar 1999
Location: Tucker, Ga USA
Posts: 12,153
Sounds like a hydro-locked mono heat valve. The insert can be replaced for $35-40.
Reply With Quote
Old 01-19-2000, 05:49 PM
Registered User
Join Date: Mar 1999
Location: Williamsburg,VA, USA
Posts: 106
similiar problem on my car. Mono valve fixed it. About a 20 minute job. on my 91 300SE the valve is located on the passenger side between the firewalls under the hood. May have to move the hoses that heat the windshield fluid, but didnt have to disconnect anything. Not sure if it was necessary, but I drained the heater just to be on the safe side. good luck
Reply With Quote
Old 01-21-2000, 07:06 AM
Registered User
Join Date: Apr 1999
Location: Cincinnati, OH, USA
Posts: 59
Can you explain more about this valve and how it works? I have a 92 500SEL and it seems that the heat does not come out as strong as it should. I hear the blower running strong in the dashboard but I have yet to be able to get a forceful stream of air coming out of the dash vents. I have tried Auto set at 78F, Auto set at 78F with red light between center vents on. When I put the defrost on it blows out strong like it should. Heat for the rear seats only comes out at the floor ducts and not at the ceter armrest duct found between the front seats. Like above it seems that when I turn the car off and restart the heater sometime regulates correctly. Any ideas?

Reply With Quote
Old 01-21-2000, 08:42 AM
Andras Nagy
Posts: n/a

I believe the center outlet in the rear is for A.C. only. Check your Owner's Manual. Mine blows only during A.C. operation, and that's what my Owner's Manual says it should do.

The heat comes out of flat ducts under the front seats, blowing back into the back seat compartment.

All this makes sense, for the MB engineers know that heat rises, and A.C. falls. So these ducts are located correctly....Andras
Reply With Quote


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

Similar Threads
Thread Thread Starter Forum Replies Last Post
Exploding Heater Cores? hill Off-Topic Discussion 3 06-03-2003 09:43 AM
A/C & heater problems on 400 SE sread Tech Help 2 11-27-2002 01:30 PM
Heater Core problem dave1shere Diesel Discussion 1 11-24-2002 11:16 PM
point gap, Carb sync and heater valve..misc problems gmask Vintage Mercedes 21 11-18-2002 09:21 PM
Heater problems MarcoPolo SL Forum 0 10-14-2002 06:51 PM

All times are GMT -4. The time now is 02:58 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2018, 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