[stevesingo]

The N52 cooling system utilises an "Intelligent Heat Management" system which varies coolant tem according to load.

This means that four different temperature ranges can be implemented:
• 112°C • ECO mode (economy)
• 105°C Normal mode
• 95°C High mode
• 80°C High + mapped thermostat mode

A couple of observations I made on my Euro 330i when using the Carly App.

1, The temp seems to stay in the 100°C range whilst driving at 40-75mph on a steady throttle.

2, When I accelerate hard it does drop to 80°C, but takes a while to recover back to 100°C.

3, I never see 112°C

4, When monitoring coolant pump rpm and coolant pump target rpm delta, I see that the rpm shifts from 40 to 240 and the delta is always low <5. This tells me that the pump is tracking the demand set by the ECU effectively.

What I suspect is that the thermostat is not tracking the same or maybe sticking, hence the inability to ever reach 112°C and hanging a long time (3-4mins) at 80°C after accelerating.

Question, is there any parameters on Carly App which I can observe the thermostat operation?

Thanks

[rjahl]

Originally Posted by stevesingo

The N52 cooling system utilises an "Intelligent Heat Management" system which varies coolant tem according to load.

This means that four different temperature ranges can be implemented:
• 112°C • ECO mode (economy)
• 105°C Normal mode
• 95°C High mode
• 80°C High + mapped thermostat mode

A couple of observations I made on my Euro 330i when using the Carly App.

1, The temp seems to stay in the 100°C range whilst driving at 40-75mph on a steady throttle.

2, When I accelerate hard it does drop to 80°C, but takes a while to recover back to 100°C.

3, I never see 112°C

4, When monitoring coolant pump rpm and coolant pump target rpm delta, I see that the rpm shifts from 40 to 240 and the delta is always low <5. This tells me that the pump is tracking the demand set by the ECU effectively.

What I suspect is that the thermostat is not tracking the same or maybe sticking, hence the inability to ever reach 112°C and hanging a long time (3-4mins) at 80°C after accelerating.

Question, is there any parameters on Carly App which I can observe the thermostat operation?

Thanks

To kill your boredom, try tracking the coolant temp with the heater or Air conditioning turned on. Those features affect the minimum water pump RPM.

[ptpending]

112 will be in a slow traffic, with start-stop

[stevesingo]

Further testing today revealed I can hit 105°C at 40mph on the flat, 6th gear (MT), which is about 1300rpm.

I can't see what conditions would allow 112°C, any lower rpm in 6th and it would be struggling. I suppose I could try in in 4th at similar rpm.

All testing done with AC off, 15°C ambient and the cabin temp set to 18°C and fan on the 2nd bar.

[desertman123]

I've had my temp go from like 105 down to 80 and then hover around high 90s while I'm idling for a while.

[rjahl]

Originally Posted by stevesingo

Further testing today revealed I can hit 105°C at 40mph on the flat, 6th gear (MT), which is about 1300rpm.

I can't see what conditions would allow 112°C, any lower rpm in 6th and it would be struggling. I suppose I could try in in 4th at similar rpm.

All testing done with AC off, 15°C ambient and the cabin temp set to 18°C and fan on the 2nd bar.

Turn of your cabin fan, I'm pretty sure just turning on the fan will increase the coolant pump RPM regardless of the coolant temp.

You can use INPA to monitor the coolant pump RPM, radiator fan speed and thermostat position.

[W37V]

My best fuel economy observed was with AC on and stead cruising at 65mph. I achieved avg consumption of 35mpg over 20 Miles. Did the same test with ac off and only managed 32mpg. Outside conditions were the same (similar). Cruise control was engaged and trip computer was reset at the same point on both trips.

Did not measure coolant temps, but oil temp was lower with AC on trip.

So you might need to have AC on to get the Eco mode.

[rjahl]

Originally Posted by W37V

My best fuel economy observed was with AC on and stead cruising at 65mph. I achieved avg consumption of 35mpg over 20 Miles. Did the same test with ac off and only managed 32mpg. Outside conditions were the same (similar). Cruise control was engaged and trip computer was reset at the same point on both trips.

Did not measure coolant temps, but oil temp was lower with AC on trip.

So you might need to have AC on to get the Eco mode.

Did you have the windows open after turning off your AC? That affects the air resistance.

[W37V]

Originally Posted by rjahl

Did you have the windows open after turning off your AC? That affects the air resistance.

Nope. Closed. Outside temps were about 66 degrees, so it was bearable.

With AC on, inside temp was set to my usual 73 degrees.

[S.H]

I am curious if it is possible to command the car which program to follow via INPA (or something else)?
The reason I ask is because I feel my engine is running too cold after installing a new termostat (not genuine BMW part). My n53 e93 has an oil temperature gauge which rarely comes up to 80-90c and it takes forever. With the old termostat the temperature quickly came up to 100-110.

[hassmaschine]

the answer is no - but even if it could, it sounds like the thermostat isn't working correctly anyway, and commanding it to change the temperature wouldn't do anything. I would replace it with an OEM one, they aren't super expensive.

[markv123]

Maybe off topic here. But do you guys also watch your oil temps on your N52 as well?
What temps / range are you guys getting?
And what is:
- cold
- hot
- really hot
- ideal
Curious to hear all your thoughts.
Cheers