No Heat. Out of ideas.

Grumman · 01-01-2024, 04:58 AM

I know this is the F10 forum, but I thought I’d get more exposure to the issue which may be more common across the series. I have and 2014 F07 530D. I am in the U.K. As the summer ended, I noticed I had no heat to cabin at all.
My car has done 265,000 miles, and has 3 roadside recoveries by the RAC this year (alternator failure, snapped timing chain and a coolant leak).

I noticed the heating issue a month after the coolant leak issue, and took it back to the (not local) garage that did the repair. They had it for a couple of hours and eventually got heat after several Blend flap resets (amongst many other things). This worked till I collected my keys and drove off, about 3 minutes.

I took it to my local indie, explained everything again. He could not find the issue, but suggested the centre vent control panel.

I have replaced the centre vent panel, heater control valve, flushed the system twice (using radiator flush), back and forward flushed the heater core with a compressor and water (several times) vacuum refilled the coolant. No change.

The diag tool I have shows no issues with the blend flaps, and I have reset them countless time.

I took it to the 3rd garage (who replaced the snapped timing chain) and left it with them.

They are convinced is a heater matrix issue, as for a few seconds there is very mild warm air on start up (after the engine is at normal temp). He says this is through, conduction, not water flowing through the heater core. He believes the water pump is ok, though it is the original pump.

When I flush the heater core, it is not exactly free flowing, but the water is going through, but at pressure. The coolant that I removed looked clean. I have used Prestone on all the BMWs I have owned, (16 years straight, 3 high mileage cars by the time I have finished with them (+270,000 miles each, 7 series). Indi says I should use BMW blue only.

The pipes going into the heater core are all hot (2 in 1 out), but this could again be conduction, not hot water flowing through.

The car itself started running a bit hot last year (I’ve owned it for 5 years) and for the first time, in the summer I had an engine temp warning message. The engine oil temp is 105 degrees (Celsius)and higher. It used to be solid at 100 for the first 4 years. The fan runs fast, except when stationary. I can’t remember what should be normal for the fan. It is winter here, and it is still running at this hot temp.

I am about to rig a pump to pass cleaner just through the heater core for a long period (overnight), but I am not expecting too much tbh.

Looking at the heater core replacement, it is not something I will do myself, (dashboard out etc), and the 3rd garage has suggested it’s 8 hours work to just get it out.

If I had a single blend flap issue, is there one flap that lets the heat in for both the passenger and driver? If not, I can’t understand how there can be no heat to both.

To recap, no cabin heat, heater control valve, centre console fan panel replaced. Multiple flushes, vacuum refill of coolant. Car running hot for approx a year, one temp warning message in that time.

I am out of ideas. Can anyone suggest anything? Thanks.

ezaircon4jc · 01-01-2024, 01:27 PM

I agree with the blue coolant. From everything I've read, the cooling system doesn't play well with anything but BMW blue.

Quote:

He believes the water pump is ok, though it is the original pump.

Personally, at that mileage, I (not being anything but a DIY mechanic) would disagree. I have yet to read about a BMW electric water pump lasting that long. I would also suspect the thermostat.

Hoa · 01-02-2024, 02:29 AM

Might be a bad thermostat. While you are at it, it is best to replace the water pump since it’s the same amount of work to do both or one.

Grumman · 01-03-2024, 03:44 PM

Quote:

Originally Posted by ezaircon4jc

I agree with the blue coolant. From everything I've read, the cooling system doesn't play well with anything but BMW blue.

Personally, at that mileage, I (not being anything but a DIY mechanic) would disagree. I have yet to read about a BMW electric water pump lasting that long. I would also suspect the thermostat.

It’s a belt driven water pump, but there may be an extra auxiliary electric pump for the heater when the engine is switched off. I may have a go at replacing both pumps and the thermostat in one go.

Thanks for the advice.

01-01-2024, 04:58 AM	#1
Grumman Registered 0 Rep 2 Posts Drives: 530D GT Join Date: Dec 2023 Location: Doncaster iTrader: (0)	No Heat. Out of ideas. I know this is the F10 forum, but I thought I’d get more exposure to the issue which may be more common across the series. I have and 2014 F07 530D. I am in the U.K. As the summer ended, I noticed I had no heat to cabin at all. My car has done 265,000 miles, and has 3 roadside recoveries by the RAC this year (alternator failure, snapped timing chain and a coolant leak). I noticed the heating issue a month after the coolant leak issue, and took it back to the (not local) garage that did the repair. They had it for a couple of hours and eventually got heat after several Blend flap resets (amongst many other things). This worked till I collected my keys and drove off, about 3 minutes. I took it to my local indie, explained everything again. He could not find the issue, but suggested the centre vent control panel. I have replaced the centre vent panel, heater control valve, flushed the system twice (using radiator flush), back and forward flushed the heater core with a compressor and water (several times) vacuum refilled the coolant. No change. The diag tool I have shows no issues with the blend flaps, and I have reset them countless time. I took it to the 3rd garage (who replaced the snapped timing chain) and left it with them. They are convinced is a heater matrix issue, as for a few seconds there is very mild warm air on start up (after the engine is at normal temp). He says this is through, conduction, not water flowing through the heater core. He believes the water pump is ok, though it is the original pump. When I flush the heater core, it is not exactly free flowing, but the water is going through, but at pressure. The coolant that I removed looked clean. I have used Prestone on all the BMWs I have owned, (16 years straight, 3 high mileage cars by the time I have finished with them (+270,000 miles each, 7 series). Indi says I should use BMW blue only. The pipes going into the heater core are all hot (2 in 1 out), but this could again be conduction, not hot water flowing through. The car itself started running a bit hot last year (I’ve owned it for 5 years) and for the first time, in the summer I had an engine temp warning message. The engine oil temp is 105 degrees (Celsius)and higher. It used to be solid at 100 for the first 4 years. The fan runs fast, except when stationary. I can’t remember what should be normal for the fan. It is winter here, and it is still running at this hot temp. I am about to rig a pump to pass cleaner just through the heater core for a long period (overnight), but I am not expecting too much tbh. Looking at the heater core replacement, it is not something I will do myself, (dashboard out etc), and the 3rd garage has suggested it’s 8 hours work to just get it out. If I had a single blend flap issue, is there one flap that lets the heat in for both the passenger and driver? If not, I can’t understand how there can be no heat to both. To recap, no cabin heat, heater control valve, centre console fan panel replaced. Multiple flushes, vacuum refill of coolant. Car running hot for approx a year, one temp warning message in that time. I am out of ideas. Can anyone suggest anything? Thanks.
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01-02-2024, 02:29 AM	#3
Hoa Major 513 Rep 1,356 Posts Drives: BMW Join Date: May 2010 Location: GA iTrader: (9)	Might be a bad thermostat. While you are at it, it is best to replace the water pump since it’s the same amount of work to do both or one.
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