Cabin Heating

[Brian H]

How does the adjustment work?

By adjusting the Bowden cable it changes the amount of hot air travelling through the heater matrix, moving the cable one way allows more cold air in and the other way lets more hot air in. If your engine temp guard get in the car is in the middle have a look at this.

 

[t-tony]

The inner cable only has so much travel when the control knob is turned. To adjust the cable you need to loosen the clip which holds the outer cable (sleeve) and move it a small amount and re fasten the holding clip. Test and see if any different. Trial and error job really.

Tony.

 

[Alan W]

Thanks for this Brian.. is it easily accessible and which side? Do you have to remove any trim?

 

[Brian H]

Thanks for this Brian.. is it easily accessible and which side? Do you have to remove any trim?

Drivers side Alan, remove the lower trim under the steering wheel and it should reveal the adjuster.

 

[Brian4]

When on cold the heater valve in the engine bay is closed so no water circulates to the heater matrix but when the heater rotary dial is moved the heater valve opens and full water flow and temperature control then mixes cold air to achieve the desired temperature, The only other possible fault is if the heater matrix is partially blocked and not enough hot water flowing to heat up. This was chased for ages by somebody else here a while back and never did cure the problem as far as I remember.

 

[Gremlin]

I've a similar problem with my 1.9 I've changed water pump,thermostat and flushed the system through and bled it. Engine temp is spot on now needle is straight up. So I'm now changing only thing left which is heater control valve. If it's not opening properly then it would be like not turning it up on heater control in the car. You could have a look at this will let you know if it works for me.

 

[oldcarman]

I believe you should be able to back flush your heater core. Remove both hoses and put water hose to the outlet side and flush till clean water comes out inlet. You may be shocked at what comes out! Also clean and lube your heater control in the engine compartment as it may be partially blocked! Good luck, JIM

 

[Disca]

Drivers side Alan, remove the lower trim under the steering wheel and it should reveal the adjuster.

Just to clarify, it's the trim directly under the steering wheel, rather than the trim that links to that trim and runs down the side of the centre console?

 

[Brian H]

Just to clarify, it's the trim directly under the steering wheel, rather than the trim that links to that trim and runs down the side of the centre console?

Trim panel 1 & 2 below just under the steering wheel, please bear in mind this diagram is for a LHD car. The centre console trim does not need removed.

Trim panel dashboard LOWER - BMW parts catalog

 

[Disca]

Thanks Brian, hopefully a job for Friday via a friend if he is free

 

[katkwak]

sorry to break in but my temp needle never reachs the middle of the dial it moves from cold to about 10 to the straight up the drops back it as never reached it normal running temp any ideas please ive topped it up & tried to bleed it using the screw by the rad fill up top

 

[Sean d]

sorry to break in but my temp needle never reachs the middle of the dial it moves from cold to about 10 to the straight up the drops back it as never reached it normal running temp any ideas please ive topped it up & tried to bleed it using the screw by the rad fill up top

I would check the thermostat.

 

[t-tony]

Could be a mechanical problem such as the lever control cable out of adjustment or even the thermostat opening too early or even stuck open (even slightly) which can prevent the heater ever getting up to maximum heat. You can buy a laser temperature reader cheap enough then you can test various points around the cooling system to verify how hot it is getting.

Tony.

 

[Sean d]

Could be a mechanical problem such as the lever control cable out of adjustment or even the thermostat opening too early or even stuck open (even slightly) which can prevent the heater ever getting up to maximum heat. You can buy a laser temperature reader cheap enough then you can test various points around the cooling system to verify how hot it is getting.

Tony.

Might not even be a thermostat in place mate

 

[t-tony]

Might not even be a thermostat in place mate

Certainly a possibility Sean.

Tony.

 

[Sean d]

Certainly a possibility Sean.

Tony.

After seeing Stacey's oil filter anything is possible mate

 

[Daz3]

Is there any way of testing the heater control valve?

 

[katkwak]

i have just bought a replacement thermostat as it seems you change them every 60 /80 k
will get it changed asap as its running in open mode

 

[oldcarman]

My car has been doing this since it arrived here. But throws out so much heat it's usually run on speed one on the fan. Doesn't seem to have any adverse effect on anything. JIM

 

[Antm72]

Mine locked open randomly one day had always been at 12 oclock and heaters that burn't your hands if pointed at them.
It started to sit at 1/4 only getting to 1/2 in traffic and then it was the only time the heat was right .
After i replaced the stat it went back to being fine.