How To Replace a Thermostat and Coolant Temp Switch on BMW M3 E90 

Thanks for the video! Besides removing the plenum and intake components, this job was straightforward and simple. I pumped out the coolant from the reservoir only (maybe 1 to 1.25 gallon?), placed a thick towel under the three connecting tubes, and disconnected them from reservoir tube to middle large tube to right most large tube in the order while positioning the two large tubes upward to prevent any further spilling. There was maybe half cup of coolant spilled on to the towel. After everything was put back, I refilled the reservoir with a new coolant and distilled water mix about 1 to 1.25 gallon. Did the engine on with heat on process twice, drove around for 15 to 20 minutes. Once the engine cooled down, rechecked the coolant level, refilled another half cup or so of coolant. No leak and all is well. Btw, the pumped coolant was clean blue color.

Nice work! I just finished mine about to start it up. Praying for no leaks haha

Thanks for this. I have a 2008 E93 M3 that has thrown an intermittent "Increased Emissions" warning. The code reader says it is due to a cooling system issue. Pretty common for German cars after 10 years to get a stuck open thermostat. The ECU decides it has taken too long for the engine to reach operating temperature, and then you get a Check Engine Light and a code.

Hey man, you are one of the few to consider draining coolant before removing the thermostat housing instead of having all the coolant leaking on the belts. I don't know why people keep doing that. Anyway great DIY

Does this cause a constant running cooling fan ?

How much coolant did you need to fill after draining the radiator? I have thermostat and sensor sitting in my office for the last 6 month 😳 that I need to get to at some point. Also, do you think replacing the coolant pipe is necessary? My car is 2011 and 50k miles... It's probably better to replace but as you mentioned, I hear they are pain to get off...

Great video! Could you pretty please tell me about how long this job took you. I am being told by multiple mechanic shops that it is 5 hours labor. Looks like 2 hours at most. Thank

Did you run the car before putting everything back together to see if there are any leaks ?

how long can you drive it like that without replacing it?

did the check engine light go off after the install ?

Hi ! do i need to emptey the coolant before replaceing thermostat ?

25:00, rubber mallet ist not really the best idea. I aways spray the 8 rubber joints of the throttle bodys with silicon spay. This works a dream

Did you’re code ever come back after doing this ?

Why couldn’t you get the cover seated correctly?