heating problem

[X5 4.6IS 2003]

Hi all
Another issue with my car if anyone has any advice please

1)Everytime i switch car on the heating comes on, even though it was not on before i switched it off

2)The air flow seems to get strong and then goes weak then strong again

3)No real heat from the heating

Over the last couple of months i have fitted a new Bosch S5 battery, a new alternator and a new fsr unit so it can't be caused by any of those

Thanks for any help
Terry

[X5LeMans]

Terry,

1) cant answer that, I never turn my heater off. I just let the climate control do its thing.. The set temperature is dependant on which key you use, one of the memory settings if you have multiple keys.

2) Erratic air flow is one of the main signs of FSR failure normally. It wouldn't be the first time a new FSR's been faulty almost on day one.  However.. Do you have the normal dual zone climate control, There is a small fan inside the control panel, if that fails, the climate control can't gauge the cars temperature so accurately, so it can make mistakes. I had this on an E39, it would start off warm, but once the car reached a certain temperature, it just blew colder and colder. The fan is fitted to the PCB, so its not easy to change. Either a new PCB, an entirely new climate control panel. Or jury rig a small fan fixed to the hidden vent on the back of the panel after you pull it out. The faulty fan will generate an error code if you have access to an odb2 code reader.

3) No heat.. Can be linked to the little fan.. But dialing heat up to +32 on the drivers side, overrides everything, it should go full heat. If you have little or no heat when set to +32, there's probably an issue with your heater matrix or the water control valves.

It could be something as simple as a loose connector too, pull out the climate control panel, and check all the connectors are good. (unplug them all, and plug them back in, that can help)

[X5Sport]

Check the upper thumb wheel in the dash air vents is set to a neutral position and also when was the last time the a/c was serviced? 

Mine started this and it was found that the gas level was very low.  I had not had the system checked in 5 years and you lose 10-15% of the gas every year.  £50 recharge and it was fine again.

Richard

[X5 4.6IS 2003]

Thanks guys

X5LeMans
Yes got the dual zone, is there a way to test just the FSR and has this got its own fuse?
i have been told that it the filteris blocked this can slow the fan down, i put it on resirc tonight and the fan seemed a lot stronger but still no heat.
with ref to the Pcb fan, i'm sure i can hear a slight fan noise coming from behinfd the controls after i switch the car off is this normal?
i will check all the connections at the weekend just in case

Richard
i never even noticed the thumb whee before ) no idea on the a/c nothing mentioned in service history though, will this cause lack of heat? if so may try this first

Thanks for the replies folks

[X5LeMans]

There is a tiny fan inside the climate control panel, it makes a slight whine, and is supposed to be running any time the car is awake (IE not sleeping). It's a tiny fan, no real power draw to run it. But without the fan, the temperatures in the car are very erratic.

I had a CC with the PCB fan failed, and believe it it sucked.. Hot for about 15 minutes driving, then progressively colder. I believe without the slight airflow from that fan, the temperature sensors inside the climate control don't react correctly.

Should still blow hot if you dial the temperature to +32 on the drivers side.  If you have no heat at all ( and the engine is warm, and you have plenty of coolant ), I would start looking at the diverter valves that send heat to the heater matrix.

I would imagine that the FSR is fused, but not sure which one you would have to pull sorry

[X5 4.6IS 2003]

[quote="X5LeMans"]
There is a tiny fan inside the climate control panel, it makes a slight whine, and is supposed to be running any time the car is awake (IE not sleeping). It's a tiny fan, no real power draw to run it. But without the fan, the temperatures in the car are very erratic.

I had a CC with the PCB fan failed, and believe it it sucked.. Hot for about 15 minutes driving, then progressively colder. I believe without the slight airflow from that fan, the temperature sensors inside the climate control don't react correctly.

Should still blow hot if you dial the temperature to +32 on the drivers side.  If you have no heat at all ( and the engine is warm, and you have plenty of coolant ), I would start looking at the diverter valves that send heat to the heater matrix.

I would imagine that the FSR is fused, but not sure which one you would have to pull sorry
[/quote]

Thanks mate just spotted your advise in another thread also so i at least  i now know the noise from behind controls is normal, i will start to check and tick things off the could be list on Sunday
I work long hours in the week and have my daughter every Saturday so only Sunday to have a play

Thanks again
Terry

[X5LeMans]

Apparently there is a chance it's a simple problem.

If your coolant level is low you can end up with a airlock in the heater matrix. There should be some way be bleed the air out. And if that's the problem you'll be back in business.

I know the e39 systems better than the e53 but it might be worth looking into that?

Good luck. Hope you find the problem.

[X5 4.6IS 2003]

Hmmmm, well had a quick look today checked fuses etc(all ok), Coolant was low so i have topped it up and the air flow seems better but:-

1) When i rev the car the air blow gets faster  :wall:
2) Still cool air from drivers side and very very slightly warmer air from passengers side
3) Still switches itself on evertime i start the car
Thanks X5LeMans
Any idea where the heater matrix is?

[X5LeMans]

If your getting some heat, you may just be working an air lock out of the matrix. There is a bleed screw which you can open up, it should allow air to bleed out of the system (plus a little coolant will come out too).

Just keep topping it up, (without overfilling) until its good. If your getting any heat at all, it should get better as you get the air out.

While your trying to get the air out, dial up the temperatures on both sides to +32 and hit the demist button. That should force all the cars coolant through the heater matrix, and hopefully push out any trapped air pockets.  Once you've got the air out, the heater should work. You may need to give a little bit of revs to pump the water through the system, and help release any trapped air.

I don't know about the on when you fire up the car, as I leave my in Auto mode all the time, so its always on. I never turn off my system, so I wouldn't even worry about that to be honest. Auto will keep you well ventilated, without any real noise, as it will dial back the fan speed to just a trickle when its not needed etc.

How's your battery voltage, if the voltage is low, as you rev the engine, the electric fan will get more volts, this more speed. Additionally as the climate control is an electrical system, (including turning on and off the water valves) low voltage is going to affect the system considerably. I wouldn't worry about the FSR yet.

The heating is supposed to save its settings to the key every time. I believe the car bases its "saved" settings when you unlock the car. So if you change keys, it will pick up the other keys settings.

Its possible you have some other faults, but keep checking the coolant, and bleeding it, and also check your battery voltages. You may just have a low battery.

When your after max heat, check the air conditioner is off (that's the snowflake). Although even in winter, you can combine air conditioner with heat, as the air con should dry the air, while the heater will keep you warm

The dial in the front vent, with the coloured dots, is so you can adjust, some people like warm head, cool feet, others like warm feet, cool head. You can use that wheel to adjust to your personal preference. While testing heater, just dial up three red dots . I normally run with 1 blue dot personally.

[X5LeMans]

Heater matrix (core) is in the dashboard!, changing it is a major job, but if you just want to inspect it, you should may well be able to get enough access to look at it. I've not looked myself, but you can probably access it by removing the carpet trim panels, and probably the under dash covers.

Based on some info from a USA/left hand drive website.. They said access via drivers side.. So I would guess to reverse that and try to access it via the passenger side / glovebox etc.

Sounds like a big DIY job, but should be enough to see if there are any leaks.. Though I would expect you would smell the coolant through the ventilation if you had a problem inside the car/dash area.

Anyway.. Check your battery, and see if you can bleed any more air from the system. Hope you find something obvious

[X5 4.6IS 2003]

Thanks very much pal, your help is very much appreciated, i will update ar the weekend fingers crossed as i'm bloody freezing lol

[Horizon]

There will be a heater valve probably on the bulkhead somewhere, these are solenoid operated. They turn the water flow on and off to the different zones, via the climate control panel. I had one fail on my 8 series as I was selling it, the guy I sold it to sorted it out as part of the deal, I used to get some heat out of it somedays, but on others it wouldn't blow hot at all, I tried bleeding the system, all sorts. I even suspected the head gasket, but it used no water, no signes of white smoke, I was about to get it pressure tested when I read a peice on the valves gunging up. I  had promised to deliver the car to Scotland for the buyer. He. Apparently made up a tee piece with a few fittings and horsetails, to bypass the valve and it got hot in the car, he ordered a used valve from a BMW breakers, it was the same valve but off a different Bmw model,  fitted it and it was fine after that.
Maybe not your problem, but worth a look, as removing the matrix will be a major job, and there's not a lot to go wrong with them apart from them leaking on certain cars

[X5LeMans]

Yup the valves can go on these. That would be on my checklist.  Can be blocked jammed or an electrical fault. I'm guessing that an electrical fault would show on an obd2 scanner fault read out.

Often with the valves you still get some heating though especially on demist mode. It's not a bad place to look though if the basic checks draw a blank.