4.4i v8, real hot in cabin

[moneytree]

I got a 2002 version 4.4i and drive in high temperature environment highway, underground parking, city traffic, etc with aircon 100% of time.


I notice that in the cabin, once in a while, there is tremendous heat developing below the steering wheel all the way down to the gas pedal. it gives me the sweats and I feel like I am being toasted slightly. getting cool air from front AC whilst feeling real hot around my legs. is this normal? it often happens when i drive around in underground parking or up a hill, also it is not just a temporary heat.
doesnt go away it stays until i turn off the car.

checking the engine temp there is nothing, inside engine bay, the coolant area to the right of the engine bay is very very hot, with hot air blowing out to the side of the engine and also the hood feels very hot above the alternator area.

to the left, the window-washing watercase, feels also very hot.
but what is below the steering wheel? it is some distance from the visible part of the engine.

[CGSTL]

Have you tried balancing the cool air flow evenly between the vents in the dash board and the vents in the leg section of the cabin? I do this by moving the thumbwheel located between the two front vents more to the red dots.

Yes, that seems like that will be changing your cool air to hot; but it actually seems to just adjust the amount of air that comes through the dash board vents vs. the lower vents. When I move mine to red dots it seems to direct cool air to my legs.

Good luck.

[E61Silver]

It might be the heat, the system uses the heat and a/c at once, you might try reducing the fan speed.

[Tomaz]

There are two motorized valves under the hood on the drivers side of the engine. One is for the driver heat, one is for the passenger heat. One or both may be stuck open. They should be closed with the AC on, you should check this; http://www.realoem.com/bmw/showparts...64&hg=64&fg=18

[moneytree]

cant I just turn off the "heat"? I only use aircon

thank you, which part would need replacemet shown in this chart?

[Tomaz]

Originally Posted by moneytree

cant I just turn off the "heat"? I only use aircon

thank you, which part would need replacemet shown in this chart?

Item 01, water valve. If it is functioning properly, the heat should be off.

[BrianX54.4is]

You can turn off the heat completley only by adjusting the temperature selector to (16°C - 60°F) and rolling the vent temperature thumbwheels to full cool. If you are still getting hot air then the control valves or controls are at fault. I had to strip down, clean and re-build the heater valves on my E34. The rubber diaphragms had disintegrated and the debris fouled the movement of the valves allowing hot coolant into the heater box contantly.

In the diagram hoses 6 & 7 deliver hot coolant into the drivers & passengers heater boxes and hose 5 is the common return to the system. If 6 or 7 remain hot when the temp is set to full cool then it indicates the valve is passing. If you can also hear the valve "clicking/pulsing" then it indicates the valve is still receiving an opening signal from the control unit. Check that the cabin temp sensor is not fouled with dust. This is located behind the small grille on the ac control panel - see page 107 in the manual item 17.

Note - you can still have warm air with ac on - this de-humidifies the air where the air is first cooled below dewpoint (the air moisture condensates and is removed by the ac evaporator) and then the dry air is re-heated to a comfortable temperature.

[moneytree]

Ok, I got the valves checked. They are fine.

In fact the heat in the legroom is not comming from Hit Air, it is actually the area below the steering wheel which feels very hot/is emitting heat, not blowing warm air as it would be from a heater.

Is this normal? It happens when I drive at faster speeds and also when I go uphill in the V8. Could it be a cooling problem?

Try to see how warm is the area under your steering wheel all the way to the pedal almost. it is a bit warm as in lukewarm when I drive normally, definately emitting some warmth, and when I push the car the area gets quite warm and I would say it feels like a fever.