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

LinkBack Thread Tools Display Modes
Old 08-04-2008, 08:21 PM
Registered User
Join Date: Jul 2007
Location: Upstate South Carolina
Posts: 1,132
83 240d a/c ?'s

I would like some input as to why my a/c will blow cold out the two center vents but the two on the side (one on pass, one on drivers side) are real hot air like the heat is on.
Anyone had this problem?

Reply With Quote
Old 08-04-2008, 09:11 PM
Registered User
Join Date: Nov 2006
Location: New Hampshire
Posts: 282
The center vents are just that and will only blow outside air or a/c air. All other vents work with the heater controls for temperature. So I would check to make sure that you have both heater control knobs set to off or the arrow pointing down. If they are in the off position you might need a new heater control valve, or adjustment on the heater control knobs.
Reply With Quote
Old 08-04-2008, 09:35 PM
Scott98's Avatar
Registered User
Join Date: Aug 2003
Location: Weston, FL
Posts: 1,254
I get cold air out of all 4 with A/C. I get hot air on the outside two but cold (outside) air out of the middle two with the heat on.

1982 Mercedes 240D, 4 speed, 275,000
1988 Porsche 944 Turbo S (70,000)
1987 Porsche 911 Coupe 109,000 (sold)
1998 Mercedes E300 TurboDiesel 147,000 (sold)
1985 Mercedes 300D 227,000 (totaled by inattentive driver with no insurance!)
1997 Mercedes E300 Diesel 236,000 (sold)
1995 Ducati 900SS (sold)
1987 VW Jetta GLI 157,000 (sold)
1986 Camaro 125,000 (sold - P.O.S.)
1977 Corvette L82 125,000 (sold)
1965 Pontiac GTO 15,000 restored (sold)
Reply With Quote
Old 08-04-2008, 10:21 PM
Registered User
Join Date: Jul 2007
Location: Upstate South Carolina
Posts: 1,132
Ok, the two heat control knobs are definetly off, (pointed down). The air I get out of the two center vents are cooler than outside air. Where exactly is the heat control valve? Is it the valve on the firewall that has a couple cables that attach to it?
Is it possible to bypass that valve for the summer?
Reply With Quote
Old 08-05-2008, 12:39 PM
dmorrison's Avatar
Registered User
Join Date: Dec 2002
Location: Colleyville, Texas
Posts: 2,694
Sounds like your hot water control valve in the engine compartment is either disconnected or leaking.
Move the heat control knobs and check the movement of the 2 levers on the valve. Also make sure the levers on the valve are actually moving. If one or both are not moving the valve correctly then you will have heat.
If they are moving correctly then feel the hoses on the engine side of the valve vs. the passenger compartment side. If the passenger side is as hot as the engine side, with the valves off then the valve is leaking.
If the valve is working correctly then there is a possibility that the main flap in the evaporator box is not working correctly and hot outside air is entering the system.
More than likely it is the water valve.

1970 220D, owned 1980-1990
1980 240D, owned 1990-1992
1982 300TD, owned 1992-1993
1986 300SDL, owned 1993-2004
1999 E300, owned 1999-2003
1982 300TD, 213,880mi, owned since Nov 18, 1991- Aug 4, 2010 SOLD
1988 560SL, 100,000mi, owned since 1995
1965 Mustang Fastback Mileage Unknown(My sons)
1983 240D, 176,000mi (My daughers) owned since 2004
2007 Honda Accord EX-L I4 auto, the new daily driver
1985 300D 264,000mi Son's new daily driver.(sold)
2008 Hyundai Tiberon. Daughters new car
Reply With Quote
Old 08-05-2008, 08:20 PM
Registered User
Join Date: Nov 2006
Location: New Hampshire
Posts: 282
Follow what Dave said and if i you need to you can put a valve inline after the heater control value.

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

All times are GMT -4. The time now is 11:20 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2020, 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