I had an issue with my Thermostat this past week and decided to replace it myself, I didn't feel like paying the stealer $979 for the repair. I looked around on the internet for a couple days and found NOTHING out there for
E9x M3 Thermostat Repairs. So here are the photos and steps on how to replace it yourself.
Time taken to repair: 3-4hrs (mechanically inclined) 4-5 (mechanically challenged)
Total Spent DIY: $120.77
Price Dealer Wanted: $979.50
Tools Needed: 10mm socket, 11mm socket, 5/8 socket, T20 Torx, T25 Torx, T30 Torx, Medium length flat blade screwdriver, Long flat blade screwdriver, 8mm crescent wrench.
Preliminary: Remove the Intake system before the first step!
First: Take off the Intake Manifold.
DO NOT unscrew the 2 bolts on the top. They have nothing to do with the removal. You will notice underneath the manifold, on the throttle bodies that there are clamps holding each one on. Unscrew the clamps until they are loose enough to pull the entire Manifold up and off. (There is a sensor underneath on the front side of the manifold that needs to be unclipped and there is another on the right back half that needs be be undone.) Pull off! (Pictures 2 & 3)
Second: Next you need to unscrew the 2 screws that mount the fuel line to the fuel rail.
Right Side Only (Pictures 3 & 4)
Third: Now unlock the wiring harness of the fuel injectors. (Pictures 6 & 7)
Fourth: Now unclip the injection pipe out of the holder and lay the injection pipe, cylinders 5 to 8, to one side. (Pictures 8 & 9)
Fifth: Disconnect plug connection on coolant temperature sensor and on solenoid connection. Both are located on the upper right of the thermostat housing. Cover to make sure dirt doesn't enter engine block. (Pictures 10 & 11)
Sixth: Open up the coolant housing (Only when the engine is
cold.) Under the car you will undo the front cover and drain the coolant from the radiator. (I think this part is optional but you can opt to do it.) Drain the coolant. (Pictures 12, 13 & 14)
Seventh: Unlock the coolant hoses and detach. Detach the coolant vent hose. Then unscrew the thermostat's 3 bolts. (Excess coolant will come out so make sure to have a sheet of cardboard under the car.) (Picture 15)
Eighth: Remove the thermostat housing forwards toward you. Clean all the sealing surfaces. Inspect the O-rings on the back half of the thermostat for damage. (Picture 16)
Ninth: Remove the thermostat from the housing. Check rubber section for damage. Insert new thermostat into housing. (Pictures 17 & 18)
Follow this tutorial on how to change the coolant out on the car and replace what you have drained.
http://www.m3post.com/forums/showthread.php?t=706073
Now simply assemble everything back together and
don't forget to put the sensors back!!!
I hope this helped as many people as possible. If you have any questions feel free to pm me or just ask.
