E39 540i thermostat replacement please help

Hello , I hope you all had a happy thanksgiving !!! I am replacing the thermostat at the water pump and would appreciate if some one could please send me a DIY preferably with pictures of this procedure as I am very new on here!! Also do I need to drain some of the antifreeze first , if so how ? And how to bleed the system I f I need to? I have searched for threads and want to make sure I have all the right info. Thanks so much, Talmadge.

Originally Posted by Talh3

I have searched for threads and want to make sure I have all the right info.

Just type /cooling system F3 into the bestlinks and you'll find all you need.
For example:

- E39 Fan shroud removal DIY (Besian) (M54) & some of the better cooling system DIYs (cn90 1997-1998 M54TU) (cn90 V8) (aioros '99-03 M54) (Ågent99 '01 530i) (pelican 3-series) (bluebee M54B25) & tricks to replace the fan clutch nut (1) & lower-hose thermoswitch o-ring (1) & to non-destructively remove the heater hoses (1) or radiator nipple (1) or expansion tank nipple (1) (2) or Oetiker clamp (1) or misplaced thermostat wiring loom (1) or broken bleeder screw (1)

Thanks for the great info. I'm gonna be replacing the thermastat today and will post results when done! Thanks again, Tal.

Its pretty easy, drain radiator using drain plug. Remove coolant pipe, unbolt, bolt new one on. Fill and bleed. Having the nose in the air helps with bleeding. Hardest bit is access to bottom rear bolt.

What's the rest if the cooling system like? I did my thermosat and literally a week later the water pump failed! If you not sure about the rest of the system I'd consider replacing it all in one go. I wish I done it it one go after getting the car....

The '97 doesn't have a coolant pipe. I believe this came on the -TU engine.

Thanks for the help !!! I am new on here and very green but am ready and willing to learn how to maintain my 540i , i am a bmw fan!! I really love this site , I've learned so much already and I appreciate you all very much!!!! Thanks again, Tal.

I replaced the thermostat and it seems fine but I noticed the vent on my drivers side blows cold air and the passengers side blows hot air when both sides are set at 90* . I've read that it could be the heater control valve, any thoughts on what it may be and how to fix it? Thanks Tal.

Unplug the heater valve. If you then get heat, it's the valve.

It could also be air in the left side heater core. Bleed the system.

Otherwise, there may be a fault in the IHKA panel.

If you're going to wrench on this car, get a Bentley manual and a scan tool.

Thanks for the reply! I'll try unplugging the valve later and post results. Thanks again , Tal.