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davidbimmerman 06-12-2010 10:33 PM

00 740iL - Overheating problem
I have a 2000 740IL, the engine has been overheating lately, i stopped and topped off the coolent but forgot to put the cap on it, stopped and filled it again and this time i put the cap back on, someone told me that it might have air in it (the system that cools the engine got air in it, and doesnt cool it) someone have any idea whats going on?

Payback 06-13-2010 11:52 AM

Hello, I hope this will help you out. Video of how to add coolant. Not saying that you did it wrong but the ball indicator is made known in this video and I found it to be helpful.

Also, This is a link on how to burp your system when air is thought or found in the coolant system.

JUNEBLOOD 07-25-2010 12:00 PM

Check the thermonstat

FABOCH 07-25-2010 03:57 PM

U definetly have air in the system...Turn engine on and open up OBC in your cluster. Open #9...#9 will show your temperature...turn heater on to 90 degrees ..Open hood and unscrew the vent screw loacted by the expansion tank... Car will idle to about 100 to 105 c
..You will see coolant bubbles escape the vent screw... Now with your hand reach the lower radiator hose escaping the passenger lower side of the radiator.......feel the temp by hand..if it is COLd.. the Thermostat has NOT open up........Kepp bleeding until that hose starts to feel warm or HOT...once hot then the thermostat has opened up and coolant is NOW flowing thru ur sstem corrctly....and Now tighten up the vent screw and ur DONE!@!!!!!
ask me how I knwo...I have bled my 7 about 11 times for various reasons........Im a DIY pro!

JUNEBLOOD 07-30-2010 11:32 AM

@faboch i like ya bmw cover who painted it

sethf33332 03-09-2015 11:52 AM

heater going in and out plus over heating,
Hey. So my 2001 740il bmw is being a bit of a drama queen. I replaced the coolant overflow tank two days ago. was driving home yesterday and saw it going towards red. I turned on the heater, put in nut and it dropped. Parked it. was a little low on coolant so I topped it off. Drove it home started to over heat and kicked on heat and it dropped. My heater started going in and out working wise. I checked oil and it looked fine. was thinking of bleeding it?? suggestions?

BMWFatherFigure 03-09-2015 12:50 PM

Why would you check the oil on a car showing cooling system problems? Throw away the thermostat and fit a OEM new one.

nando082 03-12-2015 05:58 PM

There are two fans, first is clutched and the second is a back up fan, this fan also turns on with your heater when your auxiliary water pump turns on. It looks like your clutched fan is not engaging properly.

This site has helped me out a lot. Maybe it will help you out as well.

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