X5 E53 2005 Heater Control Valve
 

My heating hasn’t worked for some time. Probably just after I had the air con fixed. I have read that if the cooling system isn’t bled properly then this can cause an air pocket that will cause the control valve to get stuck. I am assuming this is refering to the coolent not the air con coolent. Anyway, I am thinking of replacing the heater control valve. These are the steps I have so far:

1) disconnect electrical connector
2) remove control valve from side wall
3) disconnect all three hose clamps and perhaps let water run from hoses.
4) connect hose clamps to new heater control valve and replace on side wall.
5) Fill up coolent again.

Any further comments would be appreciated. Do I have to do anything to get air pockets out? Should I drain another way?

Lately, I have had to keep topping up coolent (ie water).

regards

Low heat output is usually either more coolant or the thermostat is stuck open.

Get a good scanner that will read the state of the heater valves and the heater core temps real-time.

Also easier; enable the hidden menu and display real-time coolant temp. It should get to 90°C or so quickly and stay there even if ambient is 0-10°C.

The nearly useless indicator on the dashboard stays pointed straight up for about a 40°C (70°F) range of temp including temps too cold to keep the car in closed loop performance.

If you ever noticed the needle not pointing striaght up after the car's been running more than five minutes, than it's the thermostat that is defective.

When heat isn't working, first make sure coolant is topped off, then determine the coolant temp, then determine if the aux coolant pump is working. All those things are more likely than the coolant control valve.

So, I filled up with about 2L of water and went for a drive to the post office. It’s a hot day but I think the water on the ground is a bit more than just the result of air con (see image below). The temp started out at 105 deg C then when I was driving dropped down to 93 deg C then went up again to 105 deg C and stayed there.

Question: where is the auxillary water cooler pump on a x5 E53 4.4i v8 2005?

- How many miles on your 4.4i?

- At this age/mileage, I'd recommend a complete cooling overhaul: WP, thermostat, radiator, reservoir, belts, pulleys etc. etc.

It's unclear if you said temp stays up near 105 when driving. It should be lower when driving and indicates the thermostat is likely not opening completely or you could have some blockage eg radiator plugged with bugs/leaves.

Use real OEM to help find location and existence of aux coolant pump. (Or use your scanner: my foxwell will let me tuen my aux pump on.

Thanks guys, I just had a complete overhaul, radiator, water pump, etc. The temp starts off low and rises to 105 deg but I did observe it drop down to 93 deg and then backup. I will keep an eye on it. Still don’t know where the aux water pump is. Perhaps near the overflow tank? Anyway, I will need a closer inspection to see where it is leaking. The extra water on the ground maybe due to over filling. Just thought of that then.

according to RealOEM it's here: RealOEM.com - Online BMW Parts Catalog

That's not supper clear, but if it's like the 3.0 it's close to the water valves.

Attached to, not close. Should be just above the alternator/ ps pump. You can follow the lower hose going into the heater valves and trace toward the radiator. On the 6 cyl the airbox is in the way on the M62 the coolant reservoir will be in the way. N62 I'm not sure .

It's pretty obvious when running. You can feel the vibration no problem.

Another thought, I only have water circulating and that might be why it is running hot. A coolent additive (coolent) would normally reduce the temp. It has become more water because of the constant leak and top ups. Not sure why the inside cabin heat is not working. Perhaps with all this adding there are air pockets and even one in the heater control valve. So, need fix the leak/problem first once I find it. Seems to be around the coolent expansion tank. Pressure cap/cracked expansion tank perhaps or aux water pump.