98 TDI whines when cold: 1.9-2.2k rpm

As its getting colder here is Michigan I have noticed a whine after cold starts. It happens very near 2k rpm, but only happens under load. Not speed related, just rpm. The more load the louder it is. The noise is lower pitch and sounds like if you were to a say "who" but hold the o "whooooooo..."

My questions:
1) I replaced my water pump this summer. Could it be a seal leak causing cavitation?
2) Any tips for how to diagnosis? I can't re-create unless it is under load and cold...
3) Would i be asking for trouble if I took a short drive (<1mile) without the power steering/water pump belt on. When it was cold?
4) Oil light blinks 1-2 times at engine start then goes away. It's not low on oil. related?
5) Any other thoughts?

1998 jetta mk3 tdi 310,000. I run walmart synthetic every ~5k.

Other notes:
Flushed the power steering. That didn't help.

I appreciate your time!

The water pump is probably fine, and the oil light behavior is normal.
If it's original, the turbo has a lot of miles on it. Try removing the inlet plumbing and test the shaft for wear. A bit of side to side play is OK as log as the vanes do not touch the housing. Any axial (in and out) play is not good.

I'll check out the turbo and report back.

Here is a video of what it does:
http://www.youtube.com/watch?v=8vRA0jTEa_s

Thanks for your time!

It's most likely your power steering pump. The fluid is cold making it harder to pump. Check the belt tension, if too loose it'll slip by, but if it's tight enough (without being too tight), then your fluid may be old and in need of changing.

Finally got around to taking the turbo inlet off. Sure enough there is about 1/16" of axial play. Questions:

1) What kind of situation am I in? Don't drive until I get a new turbo? Or I have some time?
2) Will I get a warning before complete failure? I imagine I would hear some nasty grinding prior to it ceasing...
3) Does anyone know of a good turbo swap guide for the AHU. I imagine it's going to be a real pain getting those bolts off...

Thanks for any tips!

Seizing up is one failure mode. The other much more damaging one is where it starts dumping massive amounts of oil in to the intake, which can lead to a runaway. That's where the engine starts consuming its own oil as fuel - it can't be shut down with the key when that happens, stalling it out with the clutch is your only option. Google "runaway diesel" to see plenty of examples of what I'm talking about. Runaways are extremely damaging to the engine, potentially quite damaging to the occupants of the vehicle and are definitely nothing you want to experience first hand.

If it were me I'd start shopping for a new turbo and take it easy in the mean time. Just be aware of what can happen.

Sent from my XT1097 using Tapatalk

It was the turbo. Swapped it recently for a new ~$225 one off Ebay. No whine now. The disassembly took about 4 hours (i pre soaked all bolts for a week or so), then I ordered all of the parts, then about 4-8 hours to install. I also did the oil supply and return lines. My 98 has 315k and counting now!

Thanks for everyone comments.