Heat

[Hoonin88]

Started the car up and put the defroster on for 10 mins or so and noticed no heat coming from the vents while stationary. Temp gauge was dead center with no dash lights coming on at any point. Adjusted the temps all the way up, no change. The scroll between dash vents is on the 3 red dots. Set HVAC on auto at 80* and after about 60 secs of driving it started to turn up the fan speed and put out heat.

Although the temp gauge was up to center, was the system still not registering as hot and not circulating coolant to the heater core? I am hoping that maybe if I left it on auto it would have eventually put out heat while warming up at idle. One day I will get my lift and be able to park in the garage again.

[Oli77]

Yep, I have had this same problem in the past. Your thermostat is stuck in the open position which (if I remember correctly) is a safety default to always want to cool the engine, diverting coolant to the radiator and NOT the cabin. Or something like that.
It is an easy DIY, right behind the water pump if I remember right.
I will let others with more experience chime in.

[Fried_Chicken]

How does that center dashboard thing work? Mine doesn’t give heat in the dead center position, only in the heat position.

[holyc0w]

How does that center dashboard thing work? Mine doesn’t give heat in the dead center position, only in the heat position.


The vent control? It adjusts the air mix. Red is warm and blue is cold. More dots increases increases the mix based on the color. I think what you're experiencing is normal if I remember correctly.

[JPMo]

If I'm remembering correctly, if my dial is set at the middle setting, I usually get heat from the lower vents with cool air coming from the upper vents. It creates this weird dual temperature affect.

[Will]

If I'm remembering correctly, if my dial is set at the middle setting, I usually get heat from the lower vents with cool air coming from the upper vents. It creates this weird dual temperature affect.

Yup. I recall reading in the owners manual of my old e28 that having warm or hot air blowing to the face and torso was sleep inducing. So, heat to the extremities (feet) and cooler air to the face / torso is the middle setting. Manual override with that selector in between the vents.

I love how engineered BMWs have always been. Too bad the bean counters and the marketing people seemed to have wrestled control of the company from the engineers in recent years.

Edit: Maybe not sleep inducing, but it caused people to become more drowsy. Not good for long drives down the highway on a cold night.

[t.er]

Yup. I recall reading in the owners manual of my old e28 that having warm or hot air blowing to the face and torso was sleep inducing. So, heat to the extremities (feet) and cooler air to the face / torso is the middle setting. Manual override with that selector in between the vents.

I love how engineered BMWs have always been. Too bad the bean counters and the marketing people seemed to have wrestled control of the company from the engineers in recent years.

Edit: Maybe not sleep inducing, but it caused people to become more drowsy. Not good for long drives down the highway on a cold night.That's quite interesting! Another interesting thing I read on E46F is that is the AC is low on refrigerant, it'll prioritize the driver first. So the vents on the passenger side will blow air at ambient temp, while the driver's side still gets cool air.

Not sure if this was the true design intent but I have certainly experienced it with my car

[Fried_Chicken]

The dials and illuminations are intentionally red b/c it doesn't cause your pupils to contract which would impede your night vision.

[Hoonin88]

FWIW- I left it on auto and the cabin warmed up just fine. Apparently blasting defrost won't warm up as the car warms up.

[holyc0w]

That makes sense, as it blasts the air at full force and it takes a long while for the engine to warm up. Running full blast probably increases that period.

[Will]

Glad you have heat. Strange that it didn't put out heat on the defrost setting even after 10 min, maybe the heater valve was stuck and became unstuck after a couple heater cycles?

Another tid bit I recall from my e28, the recommended setting to defrost was high heat and high fan with the middle and footwell vents closed but the windshield vents open. This was manual HVAC controls. I think our cars do all of these setting automatically with the front defrost button. Makes sense, as hot air will warm the windshield and prevent condensation from building up. I wish we had the heating elements in the front windshield for defrost.