[leif20]

I have a 2006 330i AT.

In September my rad leaked all the coolant out. Pain in the ass, but a fairly easy repair, or so I thought. I had the car towed to my mechanic where it sat for a few days before he replaced the rad and coolant. I was out of the country for a few weeks, so after the repair the car sat for a couple weeks. Once the cold weather hit towards the end of October, I noticed the car wasn't making much heat. Now that it's really cold, the car blows cold most of the time.

I have INPA and I was able to make a few observations:
2ef4 code - registered at 273700km, AFTER the rad job. Not currently faulted.
At idle, engine temp heats up fairly quickly and radiator temp heats up along with it. There is a noticeable delta to the rad temp. I know I have a rad out sensor (ROTS) because I can see the sensor and it reads varying values not in-step with the ECTS.
Driving with blower off causes coolant temperature to build up fairly quickly, and I can reach operating temps (~100C). Using temperature gun, temperature of oil filter housing is consistent with computer.

What is confusing me, though, is that turning on heat causes coolant temperature to drop rapidly, see video. As soon as I turn the heat on, while driving or idling, the ECTS value drops very quickly and I am not getting heat out of the vents.

Another interesting point - Using REST/residual heat function works as it should, and temperature does not drop quickly. I get hot air out of the vents (when the car is off).

https://youtube.com/shorts/jIwBCJrmsLk?feature=share

After using REST function, I turned the car back on and saw the ECTS value climb a couple degrees, but then it starts dropping rapidly again (This is with the blower ON).

So - all this is to say, my coolant temps at the ECTS/rad in drop very quickly when I put the blower on. Coolant level is normal. What could be the cause of this?

@gbalthrop I have seen your name around a lot of coolant threads, do you have any thoughts?

[gbalthrop]

Originally Posted by leif20

... 2006 330i AT. In September my rad leaked... my mechanic... replaced the rad and coolant... after the repair... I noticed the car wasn't making much heat. Now that it's really cold, the car blows cold most of the time. [If there is ANY time it DOES "blow heat", what are those conditions?]

I have INPA [Good! Please see questions below] ... I know I have a rad out sensor (ROTS) because I can see the sensor and it reads varying values not in-step with the ECTS... What is confusing me, though, is that turning on heat causes coolant temperature to drop rapidly... and I am not getting heat out of the vents.

"Thoughts":
1) Don't think of INPA (Diagnostic Software) as something that will TELL YOU what to replace or "Fix".
2) Think of it as software which supplies DATA which YOU have to use, based upon LOGIC and your UNDERSTANDING of HOW a System WORKS. YOU have to use that DATA from viewing various INPA Screens during certain conditions or settings of the System to rule out possible causes, and/or to CONFIRM the Actual Cause.
3) We are ALL LAZY!
4) We want the ANSWER. NOW! WITHOUT the effort of Thinking. That hurts, you know.
5) To solve a problem, one has to:
a) Identify the Problem, here "NOT getting heat out of the vents". Good Start.
b) Take the time to review HOW the systems (here IHKA & Engine Cooling) work.
c) Identify the POSSIBLE causes of the issue: here a) Mixed Air Flap Motors NOT directing Air through Heater Core, b) KFK Thermostat or its CONTROL not working properly, c) Module controlling KFK Thermostat (DME) signals it SHOULD receive from Sensors (here ECTS or ROTS) NOT functioning correctly, d) Radiator Fan operation, e) Coolant Pump Operation, f) Air Lock in Heater Core (was system bled/purged after Radiator work?). Check coolant level in Reservoir & Run Bleed/Ventilation Function FIRST. )There may be MORE but that's a good start.
d) Think about HOW you can test to a) Rule Out, or b) Confirm each possible cause. That requires a basic understanding of HOW the IHKA & Engine Cooling Systems work. If you're NOT sure, ask for Forum input. In this case, the two INPA Screens you have done video of confirm ECTS Signal value going LOWER when blower switched on (can't tell if ROTS signal value changes), but that does NOT address Flap Positions, IHKA INPUTS to DME, Radiator Fan Speed, ROTS Signal as received by DME (INPA screen shows value, but I can't read it if/when it changes).
e) Review INPA functions and screens that may offer DATA to Rule Out/Confirm a particular POSSIBLE Cause.
Here:
1) INPA > DME (MSV70) > F6 Activations > F1 Activations Group 1 > Shft+F1 Activate Coolant Pump. You can use that Screen: a) to simply observe Pump Speed (as % of Max Speed) and ECTS/ ROTS sensor Inputs as received by DME. That is WITHOUT pressing any "Function" button when screen opens. Just use it as you would an "F5/Status" Screen;
b) to run F5 "cooling system ventilation" or bleed procedure (attach battery charger to allow pump to run for ~ 10 minutes.

2) INPA > DME > F6 Activations > F1 Act.Group 1 > F6 Activate KFK; SAME as your video#1. Once again, just use that as you would an F5 Status Screen to OBSERVE ECTS & ROTS Sensor Inputs to DME, WITHOUT over-riding DME Control. Also observe if ANY DME Activation of the KFK heating element (to open KFK "early").

3) INPA > DME > F6 > F1 > F2 Activate E-fan. Once again, use to simply OBSERVE Fan Speed & Temp signals.

4) INPA > IHKA > F4 Error Memory. Save/Attach any INPA Screen showing IHKA Faults.

5) INPA > IHKA > F5 Status > F1 Analog Inputs. Save and attach ScreenPrint of that screen. See attached 2 INPA Tutorial pdfs for HOW to do that, and other INPA IHKA Screens.

6) INPA > IHKA > F5 > F3 Control Panel Button Inputs to IHKA. This is to check that two Thermostat settings are correctly received by IHKA Module.

7) INPA > IHKA > F5 > F4 Flap Positions. To make sure air is being directed through Heater Core (100% reading is ALL air going through Heater, 0% is NONE, as for MAX Cooling).

Don't be afraid to experiment to see HOW/IF values change with different settings. I would NOT experiment with F6 Activations (other than simply OBSERVING as described above) UNLESS you have read/ understood the "Activation Conditions" at the top of the screen. As example, you would ONLY run the Ventilation/Bleed Procedure with Engine OFF (Engine Speed/ RPM = 0 1/min).

Please let us know what you find,
George

[Bmw1939]

Originally Posted by gbalthrop

"Thoughts":
1) Don't think of INPA (Diagnostic Software) as something that will TELL YOU what to replace or "Fix".
2) Think of it as software which supplies DATA which YOU have to use, based upon LOGIC and your UNDERSTANDING of HOW a System WORKS. YOU have to use that DATA from viewing various INPA Screens during certain conditions or settings of the System to rule out possible causes, and/or to CONFIRM the Actual Cause.
3) We are ALL LAZY!
4) We want the ANSWER. NOW! WITHOUT the effort of Thinking. That hurts, you know.
5) To solve a problem, one has to:
a) Identify the Problem, here "NOT getting heat out of the vents". Good Start.
b) Take the time to review HOW the systems (here IHKA & Engine Cooling) work.
c) Identify the POSSIBLE causes of the issue: here a) Mixed Air Flap Motors NOT directing Air through Heater Core, b) KFK Thermostat or its CONTROL not working properly, c) Module controlling KFK Thermostat (DME) signals it SHOULD receive from Sensors (here ECTS or ROTS) NOT functioning correctly, d) Radiator Fan operation, e) Coolant Pump Operation, f) Air Lock in Heater Core (was system bled/purged after Radiator work?). Check coolant level in Reservoir & Run Bleed/Ventilation Function FIRST. )There may be MORE but that's a good start.
d) Think about HOW you can test to a) Rule Out, or b) Confirm each possible cause. That requires a basic understanding of HOW the IHKA & Engine Cooling Systems work. If you're NOT sure, ask for Forum input. In this case, the two INPA Screens you have done video of confirm ECTS Signal value going LOWER when blower switched on (can't tell if ROTS signal value changes), but that does NOT address Flap Positions, IHKA INPUTS to DME, Radiator Fan Speed, ROTS Signal as received by DME (INPA screen shows value, but I can't read it if/when it changes).
e) Review INPA functions and screens that may offer DATA to Rule Out/Confirm a particular POSSIBLE Cause.
Here:
1) INPA > DME (MSV70) > F6 Activations > F1 Activations Group 1 > Shft+F1 Activate Coolant Pump. You can use that Screen: a) to simply observe Pump Speed (as % of Max Speed) and ECTS/ ROTS sensor Inputs as received by DME. That is WITHOUT pressing any "Function" button when screen opens. Just use it as you would an "F5/Status" Screen;
b) to run F5 "cooling system ventilation" or bleed procedure (attach battery charger to allow pump to run for ~ 10 minutes.

2) INPA > DME > F6 Activations > F1 Act.Group 1 > F6 Activate KFK; SAME as your video#1. Once again, just use that as you would an F5 Status Screen to OBSERVE ECTS & ROTS Sensor Inputs to DME, WITHOUT over-riding DME Control. Also observe if ANY DME Activation of the KFK heating element (to open KFK "early").

3) INPA > DME > F6 > F1 > F2 Activate E-fan. Once again, use to simply OBSERVE Fan Speed & Temp signals.

4) INPA > IHKA > F4 Error Memory. Save/Attach any INPA Screen showing IHKA Faults.

5) INPA > IHKA > F5 Status > F1 Analog Inputs. Save and attach ScreenPrint of that screen. See attached 2 INPA Tutorial pdfs for HOW to do that, and other INPA IHKA Screens.

6) INPA > IHKA > F5 > F3 Control Panel Button Inputs to IHKA. This is to check that two Thermostat settings are correctly received by IHKA Module.

7) INPA > IHKA > F5 > F4 Flap Positions. To make sure air is being directed through Heater Core (100% reading is ALL air going through Heater, 0% is NONE, as for MAX Cooling).

Don't be afraid to experiment to see HOW/IF values change with different settings. I would NOT experiment with F6 Activations (other than simply OBSERVING as described above) UNLESS you have read/ understood the "Activation Conditions" at the top of the screen. As example, you would ONLY run the Ventilation/Bleed Procedure with Engine OFF (Engine Speed/ RPM = 0 1/min).

Please let us know what you find,
George

I'm curious George, what careers have you had? You are very thorough and have a deep understanding of these complex systems.

[leif20]

Originally Posted by gbalthrop

Please let us know what you find,
George

Hi George,

Thanks for the detailed reply. In fact, by using INPA and the hidden menus, watching the ECTS as I am driving, I am trying to figure out what my issue is. I took to the forum to ask because I can't seem to figure it out myself.

I've been staring at the cooling system trying to figure this out.



1) INPA > DME (MSV70) > F6 Activations > F1 Activations Group 1 > Shft+F1 Activate Coolant Pump.

I used this screen to watch the coolant pump activate when I turned on the engine. Went from 0% to 20 ish percent. then I shut off the car, and keyed back on to service mode, and overrode control. So I am pretty sure the water pump is working.

2) INPA > DME > F6 Activations > F1 Act.Group 1 > F6 Activate KFK

I also watched this screen again today. With the car hot, up to running temp, I did not see any kfk activation.

3) INPA > DME > F6 > F1 > F2 Activate E-fan. Once again, use to simply OBSERVE Fan Speed & Temp signals.


This one I actually used to activate the fan. I waited until the ECT was 94 deg C as measured by ECTS, then activated the fan to 50%. I did not see the ROTS dropping. Is this a clue? Perhaps flow through the radiator is obstructed, and my coolant loop has an issue?

4) INPA > IHKA > F4 Error Memory. Save/Attach any INPA Screen showing IHKA Faults.
See below. These faults were 10k km ago.



5) INPA > IHKA > F5 Status > F1 Analog Inputs. Save and attach ScreenPrint of that screen.



6) INPA > IHKA > F5 > F3 Control Panel Button Inputs to IHKA. This is to check that two Thermostat settings are correctly received by IHKA Module.

7) INPA > IHKA > F5 > F4 Flap Positions. To make sure air is being directed through Heater Core (100% reading is ALL air going through Heater, 0% is NONE, as for MAX Cooling).





So - with all this being said and measured - it does seem like there is an issue with the radiator. Given that turning the rad fan on does not lower the ROTS at all, or the engine temp, I suspect there is an issue with that loop. It would explain the temps dropping rapidly through the heater core, as the only source of heat is the engine block. The remainder of the coolant loop is effectively isolated. Am I on the right track here?

[leif20]

gbalthrop

Revisiting this as the weather is getting cold again!

I still don't have cabin heat. When driving and having cabin heat settings on, the heater core sucks all the heat from the coolant, the engine runs cold (70C degrees or under), and cold air blows from the vents.

I am trying to understand why the coolant loop can't build up heat. It's likely not radiator, since that seems to be transferring cold ambient temp to the coolant loop. But, the coolant loop will only get HOT if I am driving at slow speeds with no cabin heat on. Any thoughts?

[phils2]

Are both hoses going into the matrix hot?

[leif20]

Yes, they are both warm.

I had a persistent 2EF4. I replaced the thermostat today and flushed heater core per these instructions:
https://www.e90post.com/forums/showthread.php?t=2093692

I used simple green diluted at 1:3 for 20 minutes, and then vinegar for around an hour so so. By the end of the vinegar flush the fluid was running quite clean and I was happy with the flow rate.

Firing the car back up, initially the heat seemed to be working well but as soon as the fan comes on, I lose all the cabin heat and the engine runs cold. I'm digging through some old threads to try and understand this system a bit better.

This seems to discuss the same issue I am having:
https://www.e90post.com/forums/showp...1&postcount=10

There is also some discussion about the trans cooler potentially going bad here:
https://www.e90post.com/forums/showp...9&postcount=10