Started to head home tonight about 27 degrees out about 4 miles into the drive no heat and hot warning pops up on the screen. Get the car off the road open up the coolant fill tank and it is fine. Restart the car after about 5 minutes and all seams fine. Heat and warning gone. But now cooling fan cycling on off alot about every 20 seconds. Engine temp 172. This is a 2007 525. So is there a thermostat I need to replace? And how hard of a job.

 

Most likely your electric water pump is on it's way out. If you have the original water pump, get that changed as well as the thermostat and small hose that connects water pump and thermostat.

 

Water pumps fail every 70K or so. Sounds like that is your issue.

 

If you have you have never done this one before, are used to working on your car, take your time, take lots of breaks, it will take about 4-5 hours. It is not a horrible job, but it is an erector set to get the parts together in the right sequence. Mine failed 2 miles from my house... Previous week I had just taken a 1200 mile trip! Phew.

Scott
PS - I could probably do this again in 2 hours (no lift, just tires on ramps)

 

Hello All,
I have an overheating issue . yesterday, The red alarm appeared and i stopped until the engine cooled then drove home with radiator fan at full speed . I checked the water pump and looked like there was no coolant circulation. I tried to run the water pump by method of bleeding . It did not work and i just heard the sound of thermostats . Today, in the morning , I made three cycles of bleeding and every thing worked well. then i drove it for 15 minute and overheating issue appeared . What is the reason is it the thermostats or the water pump ?
Please help ,

 

My electric water pump was throwing codes for several months before it completely went. If you have INPA, pull the codes. I'm guessing you will see some low RPM codes associated with the water pump.

 

The mechanic used obd2 scanner and found no thing related to water pump or cooling system . Is it same as INPA ? The car has 76 000 miles . The problem happened a day after the oil filter cooler gasket replaced .

 

I don't have a generic OBD2 code reader, so I can't tell you for sure but, my impression is that there are BMW specific codes that the generic code reader will not find and tell you.

 

You need a scanner that can read the codes that are specific to BMWs.

 

Thanks to all that replied, Yes it was the water pump, no I did not do it myself this time. To cold for thse old bones to be laying in snow for 5 hours. Unforuntly the local guy here charged me a grand to replace it and the thermostat. WOW. any way I think when it gets 50k on it I will do it during the summer.