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Old 09-11-2012, 06:03 AM
Scott ZHP's Avatar
Scott ZHP Scott ZHP is offline
We want the Lion!
Location: PA, USA
Join Date: Jul 2003
Posts: 7,769
Mein Auto: 03 ZHP, 01 X5, 73 MGB
The aux fan controller takes inputs from a whole bunch of things including the A/C system, specifically refrigerant pressure (others are coolant temp, battery voltage, vehicle speed, catalyst temp). It probably won't spin at all if you have no refrigerant. I doubt it's seized; if you can spin it by hand, it's usually fine. There were two seperate recalls (SIBs in BMW speak) to REPLACE faulty aux fans. Might want to check your VIN against the range. Make sure we're talking about the same fan; it's an electric fan located right behind the bumper IN FRONT of the radiator.

To fill the cooling system, replace the parts you need (water pump, thermostat, exp tank, pressure cap at a MINIMUM). Open the bleed screw in the top hose. Slowly fill the exp tank with 50/50 mix of BMW BLUE coolant and distilled water. Burp (squeeze) the top hose to help remove air bubbles. When tank appears "full", start the engine and turn the HEATER on full hot with fan on MAX. If no leaks, continue to add coolant until tank is full. Run engine for a few mins to open the thermostat; top off the exp tank again and replace the cap; close the bleed screw and run for another minute or two. Gently open bleed screw to allow any air to escape; gently screw it closed (do NOT strip it, it's plastic). Allow to cool, check for leaks again and top off exp tank. Reset HVAC temp and fan settings to normal.

I don't like the all in one recharge kits from Autozone, etc. I use a manifold gauge set ($40, Harbor Freight tools) with straight R134a. The kits work fine, but it's a crap shoot for how much you're adding. You can't read the high and low side pressures using one of these kits. It's poke and hope and very easy to overcharge the system. Overcharging is as bad as undercharging.

Originally Posted by Fast Bob View Post
JUST...LOOK...UNDER...THE...CAR....for`s like checking to see if a dog is male or female....
Originally Posted by smolck View Post
A bimmer with forced induction should have a proper manual gearbox. Anything less is like french kissing your sister.
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