Heater comes and goes

[staskaya]

Owner of 2004 4.4i, heater is working when the vehicle starts, works for a bit and then starts pushing cool air. If I turn it off and turn it back on seems to do the trick or if I increase the heat temp. to max seems to do the trick too, but there is something not working properly with the unit.

Reading through the post, could the problem be with the Final Stage Resister...anyone else experienced this issue before.

Thanks for you help guys..
Soner

[DallasGV]

I would also consider the water valve #3 in the pic - RealOEM.com * BMW E53 X5 4.4i Water valve/Water hose IHKA

I had a similar issue with mine - it would only blow hot air and slowly blow cold and go back and forth between the two.

[740ilDuke]

The heater control valve is a common issue as DallasGV pointed out. The unit simply allows the coolant to flow through it by controlling the valves. It has one for driver and passenger sides.

Do you have heat on one side and not the other? With the engine warm, place the center dial all the way into the red (between your vents) and put the thermostats on 90, fan speed on high. Try to determine if colder air comes out of either side, or if it goes to cold all together.

It's like fishing in the dark in a way. The valve could be working at first, then closing as the part fails - which would cut off coolant flow or heat.

There are tons on eBay, or you can snag one at a local parts recycler. When you pop the hood its mounted on the right hand side. It's an easy swap. Just a few hose clamps and a power source. Of course you will have to burp the system when/if you replace it because you will introduce air into the system.

Incidentally, if you've tampered with anything in your cooling system (replaced fluid or radiator etc.) you could just have air in the system. That will definitely make your heat cut out.

Best,

[staskaya]

Thanks for the feed back guys...