E46 330 heater not working
Discussion
Hi all,
Just noticed the other night while coming home late from work (was a bit chilly) that the heater seems to have stopped working.
Turned the heater up to 30degrees and spun the dial on the air vents to 3 red dots... but still had air blowing through at outside temperature even once the engine was well up to temp. I then tried with the air-con but still had the same problem.
I've had a quick look through the fuses which all seem to be fine.
Is there anything that I could easily check which could be causing the problem.
Cheers in advance
Dan
Just noticed the other night while coming home late from work (was a bit chilly) that the heater seems to have stopped working.
Turned the heater up to 30degrees and spun the dial on the air vents to 3 red dots... but still had air blowing through at outside temperature even once the engine was well up to temp. I then tried with the air-con but still had the same problem.
I've had a quick look through the fuses which all seem to be fine.
Is there anything that I could easily check which could be causing the problem.
Cheers in advance
Dan
Yes mine gave the same symptoms and changing the hedgehog final stage resistor was completely effective. In fact the climate control worked properly for the first time in my ownership. Nice little guide linked to above, I wish I'd access to that when I changed mine. Beware it is an absolute pig of a job, take lots of valium before tackling it. Mine took about an hour and a half lying upside down, head wedged between the pedals trying to access one particular elusive screw only visible with a mirror. Good luck.
E30M3SE said:
Probably the final stage resistor.
Cheers for the link. It looks like a pretty easy fix (if not fiddly) Does this resistor also effect the temp?? as its advertised for fixing the fan speed in the linkDan
Dan 87 said:
E30M3SE said:
Probably the final stage resistor.
Cheers for the link. It looks like a pretty easy fix (if not fiddly) Does this resistor also effect the temp?? as its advertised for fixing the fan speed in the linkDan
If the blower is not working then this FSR is the probable culprit, if the blower/fan speed works fine then as helix suggests check the coolant level. If that is OK and has not dropped or been topped up recently from a very low level where you may have trapped some air in the system then you may have an issue with the heater valve.
ETA. how's the cars engine temp gauge?
Edited by E30M3SE on Tuesday 30th August 17:05
Hate to piss on anybodies chips here but the FSR should not affect the actual heat of the air in any way. It merely controls the fan speed. If the fan speed is behaving normally, then your FSR is more than likely fine.
If the engine temperature is fine, i.e. it sits in the middle of the dial and gets to that temperature at a normal rate, your thermostat is probably ok too.
The first thing I think you need to establish is whether or not the climate control panel is actually telling the the heater valve to send hot water through the heater matrix. To do this, run the car up to temperature and then turn off. Remove the air box and you'll see the heater control valve underneath it. Remove the electrical connector (you can actually do all this with the air box in place but maybe best to remove so you can see what you're doing). With the connector removed the heater valve should default to open, allowing water through the heater matrix. If you now get hot air then your climate control panel probably doesn't know what temperature it is inside the car. This can happen when fluff etc gets into the vents in the climate control panel. Inside there is a small fan that blows ambient air across a thermocouple. When crap gets in there, it no longer works properly. A good hoover or ideally some compressed air through the little vents should get things clean again.
If you still don't get hot air, there are two other strong possibilities.
1) Air has got into your cooling circuit and settled in your heater matrix. Once air is in the heater, it is very difficult for it to get out again. A leaking rad cap or tank can sometimes cause this. I'd agree that it's worth checking the coolant level as this could be a tell tale sign.
2) Your heater valve may have stopped working. This is quite common and its fairly easy to test.
If you're really unlucky you might have a blocked heater matrix (it looks like I have on my 330) but that is the least likely scenario.
ETA the really important thing here is to diagnose the issue, or at least narrow it down before spending a penny. I've learned the hard way, replacing parts willy nilly based on bad advice and my wallet is only just recovering!
If the engine temperature is fine, i.e. it sits in the middle of the dial and gets to that temperature at a normal rate, your thermostat is probably ok too.
The first thing I think you need to establish is whether or not the climate control panel is actually telling the the heater valve to send hot water through the heater matrix. To do this, run the car up to temperature and then turn off. Remove the air box and you'll see the heater control valve underneath it. Remove the electrical connector (you can actually do all this with the air box in place but maybe best to remove so you can see what you're doing). With the connector removed the heater valve should default to open, allowing water through the heater matrix. If you now get hot air then your climate control panel probably doesn't know what temperature it is inside the car. This can happen when fluff etc gets into the vents in the climate control panel. Inside there is a small fan that blows ambient air across a thermocouple. When crap gets in there, it no longer works properly. A good hoover or ideally some compressed air through the little vents should get things clean again.
If you still don't get hot air, there are two other strong possibilities.
1) Air has got into your cooling circuit and settled in your heater matrix. Once air is in the heater, it is very difficult for it to get out again. A leaking rad cap or tank can sometimes cause this. I'd agree that it's worth checking the coolant level as this could be a tell tale sign.
2) Your heater valve may have stopped working. This is quite common and its fairly easy to test.
If you're really unlucky you might have a blocked heater matrix (it looks like I have on my 330) but that is the least likely scenario.
ETA the really important thing here is to diagnose the issue, or at least narrow it down before spending a penny. I've learned the hard way, replacing parts willy nilly based on bad advice and my wallet is only just recovering!
Edited by Gad-Westy on Tuesday 30th August 20:33
Cheers for that Gad.
After reading through the possible problems it's struck me what very probably causing the problem. In May I got gave the car an Inspection II from a BMW specialist. Before this I had a problem with the car not getting up to the middle of the temp gauge even after a good 20 mile drive with a bit of spirited driving in the end. So I also got the coolant changed.
The next time I took the car out the temp gauge hit the red a couple of times (wasn't able to pull over to stop straight away)... Checked the coolant after a couple of mins and it pi**ed out everywhere. Took the car back to the garage and got them to sort it and haven't had any more engine temp problems since.
But with it being the summer this is the 1st time in a long time that I've tried the heater.
Cheers
Dan
After reading through the possible problems it's struck me what very probably causing the problem. In May I got gave the car an Inspection II from a BMW specialist. Before this I had a problem with the car not getting up to the middle of the temp gauge even after a good 20 mile drive with a bit of spirited driving in the end. So I also got the coolant changed.
The next time I took the car out the temp gauge hit the red a couple of times (wasn't able to pull over to stop straight away)... Checked the coolant after a couple of mins and it pi**ed out everywhere. Took the car back to the garage and got them to sort it and haven't had any more engine temp problems since.
But with it being the summer this is the 1st time in a long time that I've tried the heater.
Cheers
Dan
Dan 87 said:
Cheers for that Gad.
After reading through the possible problems it's struck me what very probably causing the problem. In May I got gave the car an Inspection II from a BMW specialist. Before this I had a problem with the car not getting up to the middle of the temp gauge even after a good 20 mile drive with a bit of spirited driving in the end. So I also got the coolant changed.
The next time I took the car out the temp gauge hit the red a couple of times (wasn't able to pull over to stop straight away)... Checked the coolant after a couple of mins and it pi**ed out everywhere. Took the car back to the garage and got them to sort it and haven't had any more engine temp problems since.
But with it being the summer this is the 1st time in a long time that I've tried the heater.
Cheers
Dan
Sounds near certain that there is air in the system then. I personally have never known a car that is such a pain to bleed. Sometimes takes me several attempts over the cause of a few days before I got the last drops of air out.After reading through the possible problems it's struck me what very probably causing the problem. In May I got gave the car an Inspection II from a BMW specialist. Before this I had a problem with the car not getting up to the middle of the temp gauge even after a good 20 mile drive with a bit of spirited driving in the end. So I also got the coolant changed.
The next time I took the car out the temp gauge hit the red a couple of times (wasn't able to pull over to stop straight away)... Checked the coolant after a couple of mins and it pi**ed out everywhere. Took the car back to the garage and got them to sort it and haven't had any more engine temp problems since.
But with it being the summer this is the 1st time in a long time that I've tried the heater.
Cheers
Dan
Incidentally, did they change the thermostat when the temp was reading low?
Afraid the cooling system is a bit of a weak point on most 6 cylinder BMW's of recent years. My 2000x 330 95,000 miler has more or less had everything replaced now, some things more than once.
Gad-Westy said:
Sounds near certain that there is air in the system then. I personally have never known a car that is such a pain to bleed. Sometimes takes me several attempts over the cause of a few days before I got the last drops of air out.
Incidentally, did they change the thermostat when the temp was reading low?
Afraid the cooling system is a bit of a weak point on most 6 cylinder BMW's of recent years. My 2000x 330 95,000 miler has more or less had everything replaced now, some things more than once.
No they didn't change the thermostat. The change of fluids cleared the low temp readings somehow. Theirs still some things I'd want done by the garage once I get the money (engine belts) so might see whether they can have another look at that all things considered.Incidentally, did they change the thermostat when the temp was reading low?
Afraid the cooling system is a bit of a weak point on most 6 cylinder BMW's of recent years. My 2000x 330 95,000 miler has more or less had everything replaced now, some things more than once.
Dan 87 said:
No they didn't change the thermostat. The change of fluids cleared the low temp readings somehow. Theirs still some things I'd want done by the garage once I get the money (engine belts) so might see whether they can have another look at that all things considered.
Maybe worth getting them to change the water pump for a metal impeller one at the same time seeing as they'll be halfway there already. The standard ones appear to be made of chocolate. 
Hi all just thought i would let you know i recently brought a 2000 e46 bmw 330ci had it for about 2 weeks and the heaters stopped working and started blowing cold .... car warmed up as it should etc fan speed worked fine etc ....all i done was took the 2 pipes of the water temp valve shoved a hose pipe in it and flushed the heater core for about 5 mins in each of the 2 pipes then bled the system .... I NOW HAVE HOT HEATERS AGAIN at the cost of nothing try before you go and buy new parts.
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