What is normal operating coolant temperature?

[civdiv99]

Agreed on the varied possibilities for PWM. This mobile tablet I'm using is dying. I'll catch up with you.

Civdiv99

Originally Posted by vfwjed

Wow, thanks for your response. The passion for automotive engineering is commendable, even if it is a only a hobby!

Maybe this should be a new thread, but here goes anyway, what is the normal operational temperature of the transmission?

I seem to recall on my X that INPA reported that the transmission temperature was about the same as the coolant temperature. About 200F and something. Again, I thought this was high; I need to check INPA again.

In the meantime, I did point the fluke laser thermometer on the surface of the tranny fluid pan and it measured about 165F.

BTW I would be interested in looking at, or understanding the how of your PWM circuit or test jig. Up to you. I have a 1994 740il e32 that is down with transmission problems at the moment. Long story, this is what drove me into INPA/DIS world.

The PWM circuit could be used to modulate (for testing) the aux fan speed too!

j