Cabin Heating

[Disca]

So it seems to me at present that the hot air from the blowers only seems to kick in when the dial is nearly at max if not slightly before.

Is this the norm or do I have another thing to figure out ?

 

[Stevo7682]

Sounds like an airlock temp gauge sits about half way max provides heat from the center vents that would all but melt steel

 

[Disca]

Hmmm max settings for me provides a nice soothing warmth but not much more.
Any easy ways to diagnose or an indy job?

Edit: Should I expect the engine to be overheating with an airlock? It seems to run fairly normally when hot at present.

Edit2: Been reading some other airlock threads, I guess if i add to the symptom list a funny abnormal airy noise when the temperature is set to anything but maximum it does start to sound like you're right @Stevo7682

 

[GazHyde]

The heaters in the Z3 are usually enough to burn the hairs off the back of your hands, so I'm also wondering if it's getting up to temperature. Where does the needle sit on the temperature gauge on the instrument bin? Should be slap bang in the middle if you are going to get any decent heat.

 

[Disca]

Needle does indeed sit slap bang in the middle

 

[GazHyde]

Yeah, I'd start looking at getting the system bled properly. There is a bleed screw on the header tank (circled in the picture) which you could try loosening carefully and see if you get any bubbles coming out when the engine is warm.

Simple place to start...

 

[Disca]

Ooo this is starting to sound like bleeding a radiator in the house haha... at least I can manage that.
Shall report back when I find time to do it, maybe tonight if I want to try do it in the dark otherwise a weekend job!

 

[GazHyde]

Yeah, pretty much the same as a central heating system. Obviously if the air is trapped around the system it may not help, but it's at least a start.

 

[mrscalex]

Mine does the same. Before and after a coolant flush where I was careful to get all the air out.

 

[andyglym]

Mine only kicks out hot air when on the move, it's been bled to death, new water pumps belts etc, new thermostat and collateral. Needle sits where it should and the heat when on the move is very very good, cool at best at idle I've had ghe front end raised to bleed it, bled it cold and hot but still no joy. Be interested to hear if and how you cure it.

 

[Alan W]

Without wishing to hijack this threat l have another heating issue.. the heat control only works at the hot end.. have it on medium and it blows cold. It feels like the heat control is all in the last 10th of the control sector.. on hot its flippin hot but to make it warm you only have to turn it back a tad.. go back to 3/4 heat and and its back to cold.. there feels like theres a bit of physical resistance at the very hot end too.. any ideas?

 

[andyglym]

Without wishing to hijack this threat l have another heating issue.. the heat control only works at the hot end.. have it on medium and it blows cold. It feels like the heat control is all in the last 10th of the control sector.. on hot its flippin hot but to make it warm you only have to turn it back a tad.. go back to 3/4 heat and and its back to cold.. there feels like theres a bit of physical resistance at the very hot end too.. any ideas?

Mine does that to. Very hot on max but same as yours, goes cool the same as yours? Mystery.

 

[Disca]

@Alan W my heating control is the same, but with much less hot air in the 10th sector!

 

[Brian4]

Without wishing to hijack this threat l have another heating issue.. the heat control only works at the hot end.. have it on medium and it blows cold. It feels like the heat control is all in the last 10th of the control sector.. on hot its flippin hot but to make it warm you only have to turn it back a tad.. go back to 3/4 heat and and its back to cold.. there feels like theres a bit of physical resistance at the very hot end too.. any ideas?

And the first post by @Disca who are both referring to the rotary temperature control not gauge I think. Mine is the same only blows hot if you turn it up fully and then I can control it if I turn it down a bit. If you try to control the temp by going from cold to hot there is very little change in output but hot to cold it more controllable. Perhaps some slack in the control cables or linkages.
As long as the temperature gauge sits at the mid point and doesn't fluctuate there should be no need to bleed the radiator.
Unless I have got the wrong end of the stick instead.

 

[Disca]

I don't think I am getting the same levels of heat though Brian, I can hold my hand quite comfortably in front of the vents on max temp, whereas above posts suggest it should be stupidly hot?

My needle sits maybe 1mm off centre towards the hot end, but doesn't move once up to temperature. Could be the angle I am looking at the gauge from though!

 

[andyglym]

And the first post by @Disca who are both referring to the rotary temperature control not gauge I think. Mine is the same only blows hot if you turn it up fully and then I can control it if I turn it down a bit. If you try to control the temp by going from cold to hot there is very little change in output but hot to cold it more controllable. Perhaps some slack in the control cables or linkages.
As long as the temperature gauge sits at the mid point and doesn't fluctuate there should be no need to bleed the radiator.
Unless I have got the wrong end of the stick instead.

Slack in the cables sounds promising as it can't be anything else as my temp gauge works as advertised. Thanks.

 

[Brian H]

You can adjust the Bowden cable on the heater matrix to change the heat setting in the dial, it does make a difference. The adjustment is behind the trim panel in the driver footwell just a small amount of adjustment is required, too far and the temp dial will not move all the way to the end.

 

[mrscalex]

Seems like a common fault/feature that you only get a hot blast at the end of the range. But Disca's problem is he doesn't even get heat then.

 

[Disca]

I do get some heat at the maximum dial, just not the expected amount.
Seems this cable adjustment / attempted system bleed are the next steps.
How does the adjustment work?

 

[andyglym]

Many thanks @Brian H I'll give that a whirl when home next.