How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Roger Your Own Question
Roger, BMW Master Tech
Category: BMW
Satisfied Customers: 3044
Experience:  10 yrs. experience as BMW Master Technician, shop foreman and dealer.
Type Your BMW Question Here...
Roger is online now
A new question is answered every 9 seconds

I have a Bmw x3 and I have replaced heater vavle clontrol

Customer Question

I have a Bmw x3 and I have replaced heater vavle clontrol the problem is it will not heat at idle blows cold air or luke warm air at 1500 rpm it will heat up to 120 degrees I think it is a flow problem because I by passed the valve it was much better. What do you think?
JA: Have you checked to make sure the thermostat is working? What about the coolant level?
Customer: Yes the temp is hot the system is purged no air in it and their is flow thru all the hoses.
JA: What year is your X3?
Customer: 2004
JA: Are you fixing your X3 yourself? What have you tried so far?
Customer: I have flushed the core replaced the control valve replaced lower rad hose had small leak as well as temp probe .
JA: Anything else you want the mechanic to know before I connect you?
Customer: thinking of putting in a pump to pull coolant thru the heater.
Submitted: 7 months ago.
Category: BMW
Expert:  Chad Farhat replied 7 months ago.

Hi, I'm Chad. Welcome to JustAnswer. I'm reviewing your question and I will be posting your reply ASAP.

Expert:  Chad Farhat replied 7 months ago.

hey how are you

1- at idle ,with heat at max ,if you rev it up does it heat start to blow hot or no change ?

2- is the car overheating now?

Please let me know

Thank You

Chad Farhat

ASE Certified Technician

Customer: replied 7 months ago.
I have no over heating . it will make heat if you rev it to 1100 to 1500 rpm the temp is in the middle the rad fan kicks on so the temp is up on engine put still no heat if you dont rev it up heater core has been flushed the heater valve has been changed for a new bmw part still no heat at idle .
Expert:  Chad Farhat replied 7 months ago.

How about the water pump ,if all above you mentioned been changed

or the heater core ,if the flushing produced rust looking water

there is nothing else there

Customer: replied 7 months ago.
The water pump has not been changed but I it were a problem wouldnt the engine over heat. and the was a little scale in the heater core..We have taken it out of town many times and on the road and no overheating problems. T he heater worked very well while running down the road but little or no heat at Idle
Customer: replied 7 months ago.
Is there a problem you know of with the water pump I some bmw have plastic on bmw pumps.
Expert:  Chad Farhat replied 7 months ago.

not if it was weak at idle when you take off it will spun faster and keep the car from not overheating ,it requires more pump flow to reach the heater core

usually the water pump fails before heater core , we see heater core failure at high mileage like 150k and up

on that model the water pump propeller is metal not plastic

Please let me know if you need anything else on it

Thank You

Chad Farhat

ASE Certified Technician