BMW Repair: BMW 540 e39 Waterpump replacement, crankshaft pulley, gasket seal

Question
QUESTION: Hi. I am looking for a guide on how to replace the waterpump on my ´97 e39 540i auto.

ANSWER: Check www.roadfly.com.  Good source for info.

Essentially:

Remove the fan.
Remove the belts.
Drain the coolant.
Unbolt the waterpump.  MAY HAVE TO REMOVE CRANKSHAFT PULLEY TO GET ONE OF THE SCREWS.
Remove the waterpump.  Be careful to keep the tubes running out the back connected to the back of the engine.
"Assembly is opposite of removal"

Key thoughts:

1.  Change your thermostat and belts at the same time.
2.  If your valley pan gasket is leaking, you're 70% of the way there to fix it now.

---------- FOLLOW-UP ----------

QUESTION: Thank You. At the risk of sounding clueless, could you please explain what the valley pan is?

Answer
The valley pan is the part that covers the area between the two banks of cylinders on the V8.  Coolant flows under it, and the gasket seal around this is a frequent failure on the e38 and e39's.

To get to it (in addition to what you have to do for the water pump), you remove the intake manifold, then the tubes running from the water pump to the rear coolant manifold.