BMW X7 E70 2007 only over heats if heater not at maximum 84 and max fan

[davidyun]

Well I finally got Ista to work. Ill update how later, but here are all the screen shots of diagnostics I did. Hoping someone will see something that makes sense.

The pump seems to work, and temperature readings at 110-120 c... reviewing now.

https://drive.google.com/drive/folde...Em?usp=sharing

[davidyun]

everything was done in garage/in P, didnt drive. Overheats after 15-20 minutes from cold

[andrewwynn]

The code says thermostat is shot.

The fan kicking on in pulse might be there car going into defensive mode.

N52 or n55 motor?

You said the pump seems to work?

It should run at full speed when it thinks there's a problem 250 rpm and 151 is my normal if ambient is less than 50f=10 c else about 70 when heater is off.

[andrewwynn]

The symptoms you describe suggest pump not running full speed. Can you see real-time feedback of pump speed?

[davidyun]

Originally Posted by andrewwynn

The code says thermostat is shot.

The fan kicking on in pulse might be there car going into defensive mode.

N52 or n55 motor?

You said the pump seems to work?

It should run at full speed when it thinks there's a problem 250 rpm and 151 is my normal if ambient is less than 50f=10 c else about 70 when heater is off.

So grateful for this and all the folks here.
Its N52
It does seem to work and pump... If I gas it past 3000rpm with heater off it seems to have the problem faster.

Seems like it is the thermostat as the water pump was replace some 5 years ago. But dang it, looks like its the same old culprit.

[davidyun]

Originally Posted by andrewwynn

The symptoms you describe suggest pump not running full speed. Can you see real-time feedback of pump speed?

Thank you so much Andrew...
Hmm maybe.. It seems to pump, but I dont know if full speed, Ill find out.
Looks like in above notes the thermostat is not cooperating, so... the old adage, replace both. I just hope it's not sensors or controller module.

Maybe I need to look at any obstruction in the hoses... but I dont think that would be the issue if the system works ok at Heater running 84' full speed. Then the car doesnt overheat.... adventure continues.

[davidyun]

Alright it looks like I should get waterpump and thermostat kit - looking at whats best, I saw one for around $400.

[andrewwynn]

FCP euro. Pay once. I used a pump from Amazon it died 1 month after warranty ended!

[davidyun]

Side note - for those having issues with ISTA+ ISTA the drivers for cable, and not having BMW Standard soft correctly installed is what was the problem.. see the video here: https://www.youtube.com/watch?v=5Edqa3v7YUs&t=89s

[davidyun]

Originally Posted by andrewwynn

FCP euro. Pay once


Sent from my iPhone using Tapatalk Pro

Roger that.