overheating when in traffic or stoping

[alexs83id]

My car 328ci 2000 has some issues , the car always showing overheat when i drive in traffic . First , I changed the electric fan that bought on ebay but still show the same problem . what i would like to know is what should i changes the thermostat , pump or the hose.. I don't want to guess. please help here i wasted money already!!

( when I drive on the freeway which is fine ),,
the fan that i bought does not comes with the electrical stuff so i just replace it with the old one ..

[bmwtech1]

Sounds like you need a water pump (starting to fail), to test this when the car is cold take off the expansion tank cap and run the car, you should see a stream of coolant going back into the tank, if you accelerate the stream should go much faster (you will need a 2nd person to check this on acceleration), sounds like you probably won't have any flow at idle in your case which is no good. Hope this helps