Heat not working, any ideas?? - PeachParts Mercedes-Benz Forum

merrim19 · #1 09-05-2006, 08:58 AM

1986 300E

Symptons:
First time I've turned the climate wheel to full heat this season, doesn't heat up after driving for a while on high way. I kept the fan on high the whole time, the fan still blows hard, but the air remains room temp.

Engine temp remains normal and coolant levels are fine. I have no reason to think it's a water pump or cooling system issue. Fan is spinning and everything else is working well.

I checked the fuse box under the hood and all is well there too.

History:
I live in Michigan and bought the car last year during a snow storm and drove it right off the lot where it had been for a year. All last season, this car melted off any ice within minutes. I don't even own an ice scraper.

So I'm worried about going into this season without the heat working. Please help if you know what I can check next. Thanks -Joe

TX76513 · #2 09-05-2006, 10:00 AM

It's probably getting close to that time of the year to remind ourselves to clean, thump, or inspect the monovalve.

merrim19 · #3 09-05-2006, 10:04 AM

Do you have suggestions on how to reach that valve? I would imagine its somewhere behind the dash.

Monomer · #4 09-05-2006, 10:19 AM

Quote:

Originally Posted by merrim19

Do you have suggestions on how to reach that valve? I would imagine its somewhere behind the dash.

Under the hood, behind the firewall.

pop off the connecter, un-screw 4 screws and pull out. Check rubber diaphram for tears, replace if torn.

TX76513 · #5 09-05-2006, 11:31 AM

Here is a link to monovalve discussion and pictures, location, etc.
http://www.kite.com/kite/w126/

merrim19 · #6 09-05-2006, 12:10 PM

I will investigate. Thanks a ton for that link. I'll see what happens after I try that valve. If it's not that, I'm not sure what else it can be.