Sorry about a long post but I don't want to leave any critical details out...

01 S4 w/ 150k. I'm the 2nd owner but from the carfax records I know it's been well maintained (all on time and dealership serviced) but now I'm loosing coolant. Not while driving (that I can tell) but after I come to a stop and shut off the engine. I don't see any leaks right away but after it's cooled ~ a cup can be found under the car.

I also checked for a pool of coolant after my drive to work this morning (4 mile drive) at 1:00 pm. During the drive in, the car was barely warmed up (coolant was warm but oil temp was still not warm) and I found there was no coolant underneath. Yesterday when the car was fully warmed after driving 15 miles to a friends home I had a puddle underneath when I came out to drive home. When I got home, I let her idle for a couple of minutes and had no puddle underneath. Later last night I went back out to check (an hour or more after shut down) and there was a new puddle of coolant/water.

I don't detect any sickly sweet coolant smell when driving which I expect w/ a typical coolant leak so I'm hoping this is a known error that's easy to diagnose and cure.

After I posted the above on AZ's forums someone suggested the Secondary Coolant Pump. I found an Auxiliary Water Pump in the Bentleys (item 5 in the enclosed diagram) but I'm wondering if this is truly the cause (before I start digging into it) or if it could be something else?

I understand it takes 2 hours to R&R the pump. If I R&R this item, what else is accessible enough that I should go ahead and replace it? Plugs? Timing Belt? My leaking Driver Side Valve Cover Gasket?

Last but not least I heard it is possible and definitely easier to R&R w/out removing the intake manifold however I have not found any hints on how to do this proceedure w/out removing the intake manifold. Any idea's on how to do this would be greatly appreciated.

TIA