2011 535i xDrive, 110k miles, all original water pump, thermostat, fan, battery. Fan is coming on intermittently on low speed after 10 minutes warm up with the heat is ON. Fan does NOT run when heat is turned low. Tested the water pump using the bleed procedure and it does run at various speeds in the 10 minute bleed cycle. I wonder if the old battery (i.e. occasional low voltage over night) may be the problem, or if the water pump is dying at low speeds. Suggestions to test further?
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Ok that’s a good thing mate do not bleed it just do it this way put the coolant in when you have the waterpump changed fill the waterpump up with coolant before refitting it and the hoses as coolant from the reservoir doesn’t get to the wate quick enough then start the car and let the waterpump do its thing o it’s own leave the cap off radiator on lowest setting and bleed that way do not kick that pedal and over heat the waterpump motor
Your waterpump is failing mate it’s the start of failure where it’s slwoing down stop bleeding the system before you completely kill the pump this is why I tell everyone in the us stop draining your coolant and renewing it there is no need for that here in the uk we do not do that and never ever bleed the system with the waterpump that’s why we don’t need to change them here minesweeper on 155k still on original water pump why because we don’t touch the coolant no need what so ever the moment that punp runs dry which it does the moment you drain the system that’s it the pump is empty when you engage that pump it runs dry and burns out before the coolant gets back to it after refill lessons rule number 1 stop changing your coolant in the us and stop bleeding your cooling system