1993 318I Heat problem. help I am freezing

[computeme]

Hi. This last 2 Days I found a new problem with my 1993 BMW 318I and I need to fix it fast. Here are the symptom,, I need to Defrost Front Windshield so I turn the Car on and let it run for 10 Minutes, Engine Temp is normal and Fan Works, Controls set to heat but there is not Hot Air Coming out. When I start Driving, then the heat starts to come out. when I come to Stop or Idle, once again Cold Air. It is bad when it's cold outside and you are trying to stay warm. I have new Water pump, No Over heating problem. I am suspecting the Control Valve in the Engine Compartment but I don't understand why I have heat when I drive. Has anyoneelse had this problem. Are there valves inside the car that I need to check. Appriciate any help.. Thanks

[greenbeem]

I don't know if this will help but do you have this knob, and is it set to the red position.

125590

[325ic a beer]

Someone ever check to see if you actually HAVE a thermostat in there? ( In the thermostat housing..)
You need one if there isn't one in there.

[greenbeem]

Thermostat or not, the coolant still warms up. It would just take longer for the engine to warm up because the coolant is circulating as soon as the engine is running.

[greenbeem]

Disregard that please, my brain is stuck in "first" tonight. :banghead:

[zachiepie]

Nope. You got air in the coolant system. You know how to bleed it out?

[Andycapps]

I have bled and bled my cooling system over and over..and my car is still doing this very same thing. The coolant level isnt dropping. I get warm air going down the road and it gets cold when i come to a stop. I'd guess that your car has air trapped in the system or the heater valve is bad. I have pretty much decided that my heater valve is shot or the heater core is partially clogged.

[computeme]

I try to bleed it today but When Icome to a stop and REV the Engine Up, then Hot air comes out but when the Rev comes down, the cold air comes out again. Heat Valve can be tested outside the System. I won't change it until I am 100% sure that is bad. Core being clogged is a possibility but when you get hot air at all, kind of makes me think that is OK.

I froze my rear this morning.

[spanieldecks]

hi there, you may have a clogged internal temperature sensor. Have a good look at the climate head unit and clean out all the muck from the sensor. I had the same trouble, but it turned out the sensor was reading interal temp (nice and cosy from the radio/dash) whilst I was freezing!

Hope this helps?

[computeme]

I will check the sensor. During Lunch I popped the hood up and I noticed that I very low on Anti Freeze and I hope that is the reason why this is happening. AIR probably is the problem. When I changed the water pump a while back, Icould not understand why I didn't need as much coolant than I put in, I hope that is the problem. I don't think heating Core is blocked because I maintain my coolant very well. Either A Valve or Air in the system due to low coolant could be causing this but, over the weekend I will have a better idea.

[computeme]

I think My low Coolant was the problem. I opened up the Bleeder valve on top and added 1/2 gallon of liquid and the heat seems to have come back. I have to wait for cold day to make sure. I might have a slow leak somewhere in the system. Thanks for your help fellows.