cdavis108

Changed out the Thermostat, chasing a p0597 issue.

Now when I start the car I can see the engine temp rise to normal operating temp, but the cabin heat does not work until I do a power cycle.

After I turn the car on, the heat will come back, not HOT hot, but better than luke warm. It will not be overwhelmingly hot at anytime, and will only remain warm for ~10 minutes. When the cabin heat goes away, I can see the engine coolant temp go from 180f(warm in cabin) to 232f(cold in cabin). It's as if the Thermostat is closing...

The only change I make to get the heat back in the cabin is turning off the engine and turning It back on.




I also have a code E284. Pump works for the auto air purge though... Internet says that e284 is the communications with the water pump... Could the pump need replacing? The only way I get heat in the cabin is if I power cycle the whole car. And then the engine temp goes down and the cabin heat goes up, for ten minutes at a time... help.

cdavis108

According to this: 2E81, 2E82, 2E83, 2E84, 2E85 Waterpump Malfunction - Bavarian Technic

I need a new water pump. The plug metered: pin 1 12v, pin 2 12v, pin 3, 8v... New pump time. I'll post after install to provide results.

scottalexander

Let's start with the obvious and easiest.

When the car reaches operating temperature (and you have your iDrive climate control set to 4 bars red), go touch coolant hoses 1, 2, 3 in the pic below coming from the heater control valve to the firewall.

If they are not hot, the heater control valve is malfunctioning.

There are two valves in the heater control valve. One might work, the other may not or operate intermittently.

Next:

Make sure your coolant system is bled properly.

cdavis108

ScottAlexander, Thanks for the pro tip. I followed your direction and confirmed that the heater valve were functioning. I'd have been upset if that had been the issue. The problem went away with a new water pump. I was also able to clear the E284 fault. I think the 10 minute cycle time on the previous pump was like a 'safe mode' function due to comms loss. New pump installed, and the ECU can talk to the pump. Thanks.