Its just not my day... Coolant help!

[CLS70]

Originally Posted by BustedKnuckles

FINALLY!!!

After searching and searching I finally found the solution...

the 2007 E70 does not have an electric water pump. The procedure that everyone keeps telling me to do is not correct for this one year

Why BMW decided to do one year of the E70 without an electric pump is beyond me but that's the case. I found a post on BimmerFest with a guy that was having the exact same issue.

All I had to do was fill the expansion tank. start the car, leave the expansion tank cap off and let it run for about 15 minutes with the heater on full blast and keeping an eye on the coolant level. drive it around a bit and then re-check the level. DONE!

What still boggles my mind is what caused the leak in the first place... because this is EXACTLY WHAT I DID when i originally attempted this job yesterday. And suddenly, the coolant sensor is leaking like a siv...

Looking at the old expansion tank and temp sensor (that I just replaced with a new one) reveals that the temp sensor O-ring is GONE... like not there at all... POOF! So again, I have no idea what caused that but now the problem seems to be fixed.

Glad you completed the work.

Just to clarify my 2007 e70 3.0si DOES have an electric water pump (I just replaced it); the bleeding procedure worked as stated in a post found here and the radiator had TWO drain plugs (one blue in the bottom and one red in the driver side)

[the_ulf]

first: i still don't quite understand what exactly we are talking about here. the main rad has not really a lot to do with the AC. i'm not aware of any N62s with an electric water pump. those are found on the newer straight 6s because their design no longer allows for a mechanical pump. the N63s have an auxiliary electric water pump to cool the turbos. that's about it, as far as i know
second: if there's really no drain plug on the rad you could always carefully undo one of the bottom hoses and the expansion tank cap and gravity will do the rest. just see that you don't let it go everywhere. obviously that's not going to drain *all* the coolant, that's something you can only achieve by actually pulling the entire cooling system, so there'll always be some amount of coolant remaining.
third: you can actually turn on the ignition without starting the engine. just don't press the brake pedal.