71' Mercedes 220d No heat. - PeachParts Mercedes-Benz Forum

CvdH · #1 08-28-2010, 02:57 PM

Hi my mercedes 220d with 150,xxx miles is not getting any heat inside the car. The blower/defrost fan works great, even the AC blows ice cold but i'm not getting any heat. I turn off the AC and move the climate control levers to the full on "hot" position but no heat whatsoever comes out (with the fan on or off) even if the car has been driving for hours. The temperature gauge in the car is usually always at 175 on mild 65-70 degree days and a bit above on hot 80-100 degree days. Any idea what might be wrong? Any help would be appreciated. Thanks!

vstech · #2 08-28-2010, 03:11 PM

got any pics of the engine compartment on that car? most of us talk about the 123/126 cars here. in 71 I'd guess on wires pulling valves to operate the heat. my old toyota had em.
best thing I can offer is to follow the hoses that exit and enter the head and see where the controls are and see if you can discover the problem.
sorry I'm not more specific.

CvdH · #3 08-28-2010, 03:29 PM

I actually do have a picture of the engine lol. I know where the little box the wires from my climate control levers go to is. If you can find it in the picture its on the top middle/right of the engine compartment it has 3 hoses coming out of it. When im home i'll try to follow those to their point of origin and hopefully find a what the problem is.

PS i have gotten a proper battery since the picture was taken lol

If the pic dosn't work heres a direct link : http://img266.imageshack.us/img266/4510/dsc00971qw.jpg

dude99 · #4 08-28-2010, 03:35 PM

I had a similar problem on an old ford truck of mine that used the cable pull system. Sometimes the clamps that hold the cables from flopping around deteriorate and allow the outer sheath on the wire to move instead of the wire itself. Or sometimes it allows the wire to bind\bulge out where the clamp failed. Either way trace each cable from the dash to the box (easier ti have someone operating the lever while you look for the issue)

79Mercy · #5 08-28-2010, 03:36 PM

Im assuming you know that there are 2 fans on the W114/115 series. One for the AC and 1 for the heat.

Im that picture it appears your heater valve are OPEN, so hot coolant should be cirulating through the heater core.

Did you turn the green AC knob all the way counter clockwise to close the AC vents, and open the the ventilation vents?

What happens if you open the heater valves, and turn the green knob counter clockwise while driving. Hot air should blow out the vents if your moving.

CvdH · #6 08-28-2010, 03:46 PM

I actually do not know that there are 2 fans the only fan i know of is the defrost fan. I did turn my AC counterclockwise and did open the vents. What green knob do you mean?

79Mercy · #7 08-28-2010, 03:50 PM

There is a knob on the center console to the far left. Turn that all the way to the left. That will close off the AC vents and open the ventation vents.

Or you can reach down under the dash to the right of your accelerator and pull the vacuum actuator rod all the wayy DOWN. Now open the heater valves and drive, air should blow through the vents. You might have a vacuum leak which would cause the switch on the dash not to work properly.

See my heater blow is seized up, so in the winter months I only get heat while im in motion.... To much a pain to replace so im not worried about it.

CvdH · #8 08-28-2010, 03:57 PM

Alright i will try that hopfully it will work thanks a lot for your help! I live in North Idaho where it gets -20 F so i thought it would be nice to have my heat working before the cold kicked in in a few months lol

t walgamuth · #9 08-29-2010, 05:57 AM

If you verify all the valves and flaps are valving and flapping as they should the heater core could be plugged. If it is plugged you won't get any heat from it. It might be possible to back flush it in place by removing the hoses and forcing water through it the opposite direction from what it normally flows. If you do that and a bunch of crud comes out you will know you did some good.

And the core can be removed and taken to a rad shop ultimately for a professional cleaning.

CvdH · #10 09-12-2010, 02:02 PM

Ok, so I have turned the AC knob all the way to the left with the defrost blower on and it seemed to get a lot quieter so i'm figuring thats because the AC is now totally off. I also reached under the dash and saw the vacuum actuator rod thing you were talking about and tried to pull it all the way down but it appears that it is already down. After doing this i opened of the heater flaps and took a drive for about 30min at highway speeds and no heat with or without the blower on and im not getting much air through the middle vent unless i have the blower on.

So now I park it and let it cool down and then open up the hood and take off all three hoses from the little heat control thing. I get my garden hose and force water through the one on the right and left and water comes out the other one with no real problem the and the same with the left side. After doing this again, I took it for a good 30 min drive and still not heat, but (I don't know if this is related or not) a lot more air came out of the middle vent while driving without the fan on. But unfortunately still no heat :| After the drive I open the hood to see if any of the hoses are even getting warm and the main hose going into the heater box is but the other two aren't at all. But, the strange thing is when I forced water through the middle hole water did come out both the little holes on the sides so I'm not getting why they're not getting warm? I also tested the little flaps while i was pushing water through the middle hole and both were able to stop the water or totally let it pass without hesitation.

Sorry for the long post but i want to have heat! its already freezing at night. Is there anything else i can try?

Thanks in advance!