DIY: Water Pump, Thermostat, Hoses & Coolant Flush : X5 3.0 Auto

[anthonytexas]

I've been reading alot about my AC issues and everything points to the AUX fan not working properly. You know, the "my AC won't blow out cold air until the engine is driven for about 5-10 minutes" issue. It is not that my AUX isn't working because it does eventually spin and blow out the cold air. I tested it and see that it does spin (and stop when the engine shuts off). So in this DIY, I noticed that you pull out the AUX fan switch to 'clean it' and put back in. I'm wondering if my issue is more along the line of the AUX fan switch being faulty and not the fan itself. I don't want to replace the fan if only to find out that something else was causing the fan not to kick on when the engine is cold. Wonder if there is a way to test this.

[cn90]

I wrote many DIYs for E39 forum so I am very familiar with the E39 setup.

I come from E39 (1998 528i), so we do cooling overhaul as preventive maintenance.

When I did that, I replaced most items in the cooling system. I wrote it up below for the 1998 528i:
ENTIRE COOLING SYSTEM REPLACEMENT Tips and Tricks (Very Long, Enjoy!)


Now, for the 2006 X6 3.0L MT with 113,000 miles, I am thinking out loud as preventive maintenance:

REPLACE:
1. Thermostat by Wahler, PN 11537509227 $55
2. WP by HEPU $62 (I have had HEPU in my E39 for 8 years, zero problems)
3. WP Pulley b/c this thing is plastic and usually cracks at 140K or so. It is cheap at $22.
4. Reservoir: BMW PN 17117573781, $76. This is b/c I saw some posts where people reported cracked reservoir at 125K.


CHECK AND REPLACE IF NECESSARY:
1. Fan Clutch
2. Fan Blade
3. Pulleys x 3 (incl AC system)
4. Belts x 2

KEEP:
1. Radiator because it rarely leaks before 150K.
I have had good success with Nissens radiator in my E39 for the last 8 years.
Anyone here has experience with Behr?
2. Radiator Hoses x2 because it rarely leaks before 150K.


Any opinions will be welcome!

[Wayne's World]

Originally Posted by anthonytexas

I've been reading alot about my AC issues and everything points to the AUX fan not working properly. You know, the "my AC won't blow out cold air until the engine is driven for about 5-10 minutes" issue. It is not that my AUX isn't working because it does eventually spin and blow out the cold air. I tested it and see that it does spin (and stop when the engine shuts off). So in this DIY, I noticed that you pull out the AUX fan switch to 'clean it' and put back in. I'm wondering if my issue is more along the line of the AUX fan switch being faulty and not the fan itself. I don't want to replace the fan if only to find out that something else was causing the fan not to kick on when the engine is cold. Wonder if there is a way to test this.

In this DIY I did clean up the switch and replaced the o ring. One way to test would be to unplug it. If the behavior doesn't change then you know its likely faulty.

2002 Sterling Gray Metallic M5
2006 Shwarz Black Metallic X5 3.0

[nebilex]

Hi do i still need to drain all the coolant if i am only changing the thermostat? Also how did u clean the surface after removing the thermostat?

[Wayne's World]

Originally Posted by nebilex

Hi do i still need to drain all the coolant if i am only changing the thermostat? Also how did u clean the surface after removing the thermostat?

I don't believe it's necessary to drain all however you will lose whatever is in the hoses when you disconnect. But chances are if you're replacing the thermostat due to age/time, it might be a good idea to replenish the coolant as well.

As for the surface it was pretty clean and I just wiped it. I would suspect if you had any more than surface residue it's probably due to corrosion of some sort and you might have to get a little more aggressive with a cleaning agent or even something to chip away at it. Be careful not to score the flange as you don't want to cause a leak.

[draytek]

Hello,

A little bit late, but... from the 10th picture, looks like you have (had?) also a leak on the power steering hoses?
Cheers
d

[Wayne's World]

Originally Posted by draytek

Hello,

A little bit late, but... from the 10th picture, looks like you have (had?) also a leak on the power steering hoses?
Cheers
d

Absolutely. I don't think I've ever had a bimmer that didnt have a power steering leak of some sort!

[draytek]

Originally Posted by Wayne's World

Absolutely. I don't think I've ever had a bimmer that didnt have a power steering leak of some sort!

Well, I had leaks of those hoses, I've changed the power steering pump and the steering rack, and I still have a problem - no power steering.
Apparently the GM3 module have some transistor controlling the servotronic valve. The transistor can be dead or in protection mode, sending low voltage to the valve. I'll have to check that or I can muscle my upper body
Cheers
d

[GABRIEL]

I replace my water pump two weeks ago on my 2006 X5 M54 engine with 108,000 miles. To my surprise my engine water pump was metal or a composite material similar to metal, not the plastic compound that is mention all over the forum. I was kind of upset because it is recommended to replace all the cooling system parts at 90,000, I waited 18,000 more and still no sign on ageing on any part replace parts.

[nebilex]

You are upset that you didn't see any sign of ageing? Are you upset for changing what "looks" to be good parts?

Am i reading this wrong..