The green one with the sealant line on it looks exactly like the OEM one, and really is they way to go if the other one doesn't have that.

Green one it is!

I finally (just now) got this fucker off. Even after dousing the coolant pipes with wd-40 (inside and out) and had to hold the pipes in place with a pair of channel locks and pry each side off. Then removing the WP proved to be another challenge. My original pump seems to have some sort of temp sensor mounted right on top which I had to remove with a 7/8" box wrench. I don't see where this goes on the new pump... anyone?

Anyway once i did this I could not for the life of me get the bastard around the EGR pipes. I finally figure out that i had to move the belt tensioner to the fully upright position and then i was able to wiggle her out.

Well now I just need to sanitize the area and peel the old broken (green) gasket off with a old credit card. Probably need to go over all the pulleys again to make sure this is no WD-40 left on them and do some general engine bay cleaning.

OK disregard there is a threaded hole for the temp sensor on the new pump too in the same spot :-) Well it's all thoroughly cleaned now time to button her up. Got the new WP fitted, gasket dropped right into place. I lubed up the o-rings and the coolant pipes with some BMW antifreeze - still wasn't that easy to slip it in so I would DEFINITELY recommend this step.

seeing that you are fresh on this topic, I need to replace my thermostat very soon. My 04 3.0 is not producing any heat and the temp gauge reaches 1/4 at best. Couple of questions regarding this...

1) Do you think I should change my water pump while I am in there? I have 71k on the X
2) Should I completely drain the coolant from the rad and the engine block?
3) Any other hints while I try to change the thermostat? I have the gasket and thermostat already.

Thanks

Yes! Change the water pump. Inspect your pulleys and your belts

1) Yes - they are inexpensive, and yours will probably fail at some point might as well do it while you are in there. And if you have higher mileage.
2) Yes - especially if >4 years since last flush. It's relatively easy to do too.
3) N/A - I have 4.4i, I know 3.0 has a less beefy t-stat & water pump and I have heard it's a easier job.

If belts are 4-5 years old or have a lot of mileage I would just change them. Otherwise definitely inspect them for cracking. For $40 you can have peace of mind.

OK - so everything is put back together now and naturally the battery is dead from opening and closing the door after not driving the car for almost a month.

Question about the filling process. What Magnum's article suggests and TIS suggest seem to differ.

Magnum:

• Mix the proper mixture of coolant and water, I used 50/50.
• Fill the expansion tank SLOWLY until the dipstick tells you it’s full.
• Put the key in the car, turn it to position 2 and turn the heater temp up to 90 degrees and put the fan speed to nothing.
• Now start the car.
• Go back to the front and SLOWLY refill coolant as needed until the dipstick says full, refill as necessary.
• Once the cars temp has hit the first white notch on the gauge, have your helper rev the RPM’s to 1000.
• You’ll start to see bubbles coming out of the expansion tanks bleeder valve.
• Wipe as necessary or let your pan catch it, your choice.
• Once the bubbles stop, and it appears to be all coolant let it keep going……….for about one minute.
• Then close off the bleeder screw, put the expansion tank cap on and you’re DONE……..!!!!!
• The following morning check the coolant level and fill to appropriate level.

TIS says to:

1. Turn on ignition.
2. Set heating controller to maximum temperature.
3. Set fan to low setting. This opens the heating valves and starts the auxiliary water pump.
4. Perform filling operation slowly.
5. Pour coolant into coolant expansion tank up to max. cold fill level.
6. Close vent plug when bubble-free coolant emerges
7. Close coolant expansion tank.

Magnum's is wrong about the fan speed settings, so maybe that was a typo on his part. As the TIS says, the fan speed needs to be set on low so the heater valves will open and aux pump (little internal waterpump in the heater valve) will be running. I don't know if the revving will be needed, but I guess it couldn't hurt either. Just be careful since this is a hot and messy job, but there doesn't really seem to be a better way w/o making a mess.