No heat?......
 

HI all,
Trying to diagnose my failed heater problem. Had dealer replace overflow coolant tank last month. Just replaced the final stage resistor in an attempt to fix the problem that I had no heat coming out of the heater. Temp guage behaves properly and rises to normal like it always has. Motor responds and runs well. Fan blower for front and rear heat is running smoothly at all settings. Its just that the air coming from the vents ( all combinations tried) is cold. Once or twice when at highway speeds the heat did blow hot for a few minutes?..then went back to cold...odd...it is almost as if the vent gates are not working properly like always on outside air intake......any suggestions where or what to look at next? Thanks in advance, I couldn't own this car without this forum. 2001 X5 3.0gas engine, standard transmission, 110kmiles.

You have a bad heater control valve, part number 64 12 8 374 995 or the auxilary water pump is dead, part number 64 11 6 913 489

Number 1 or 17 in this link. I have never seen a bad auxiliary pump so go to the valve first, I'll bet it's stuck closed.

http://www.realoem.com/bmw/showparts...16&hg=64&fg=18

:iagree: I've only repalced 1 aux water pump in over 4 years. I'd suspect the valvec as well.

Heater control valve
 

Is this a potential DIY - or do I bite the bullet and head to the shop? Did the FSR myself -- having the same issue described above.

You can do this yourself if you can do a final stage unit. Try to keep as little air as possible from getting into the system when you remove the valve.

Ok Ifixed it. Get this. BMW of Idaho Falls put in my new expansion tank 450 miles ago. Seems they DID NOT bleed the system and left me with a big bubble of air which settled into the heater. I do not turn on the heat often only in the last week once or twice as it has gotten cold here. I guess there was enough coolant in the system to keep the engine from overheating, NO long trips in the last 450 miles usually >20miles round trip. So I guess I lucked out here. Did the bleed valve thing added a gallon of coolant/antifreeze and all seems to be working fine!....go figure? I had already replaced all the hoses last summer which probably tweaked the tank and caused it to burst. Thanks again to all who replied so quickly...up here in Northern Wyoming ya gotta have heat after Thanksgiving...haha.

process?
 

I did a quick scan on the site and didn't see any posts from members that had completed this fix. Any idea if a step by step process is out there?

Hi, with cold weather I realized that I have identical problem with the heater blowing only cold air. I am wondering whether in your opinion replacing the final stage resistor should be my first step and was it necessary in your case – this is an easy DIY so I am debating whether should I try it before taking my car to a dealership. After reading many posts I have noticed that there many instances were bad resistor was the cause for heater not working properly but not when the heater produces only cold air. I would appreciate your advice. Thank you.

The final stage resistor has nothing to do with heat output, just air output. As long as it is blowing air at the correct volume, the FSR is good.

I would suspect either the wheel beetween the vents set to cold, blue. (you'd be surprized how many people forget about that!) The heater control valves, or an air pocket in the system.

I agree with you guys that the resistor controls only amount of the air output thus most likely is not the problem. I am thinking that the thermostat might be stuck because when on the freeway the car stays cold as the radiator is cooled down buy the driving, when I get off the freeway the radiator is getting warmer and I noticed the temp gauge is rising while slightly warmer air is blown inside of the car.