Yes this is an odd question. I'm still no further ahead in my 3-4K rpm harshness self-diagnosis originally noted here:

https://www.6speedonline.com/forums/...e-shutoff.html

In the meantime, I have managed to loosen the serpentine belt so that I could inspect and shake the pulley bearings, water pump, alternator, etc, to see if if any had bad bearings. It doesn't look like it (but I don't know what a subtly bad bearing/water pump/alternator feels like) and so I suspect I will have to take it in to a mechanic instead.

I thought of one thing though and wanted to consult with people here. If I take the belt off and start the engine on battery power, would I do any harm if I ran the engine with the belt off for a brief time, say less than a minute? I still am wondering if it could be a bad pulley bearing/water pump/alternator. And thus if I take the belt off and start the car so that nothing is driving the any of those and the engine is smooth, then one of them should be the culprit, no?

I am putting forth this silly idea because when one of my old cars had a noisy, growly engine that was due to a bad shaft on the water pump, the noise completely went away and the engine became an silky smooth wonder when the water pump pulley shaft snapped off... I'm thinking of simulating this by removing the belt and running the engine briefly.

 

I can't answer on running the engine without the belt. I do know that a bad bearing may sometimes only become apparent under load(belt tension.) So just spinning the bearing may not tell you anything. Running the engine for a short period seems like a good idea for an old iron block engine with noises. I'm not sure I would do it on an aluminum block engine though. This is assuming that the 996tt engine has a belt driven water pump of course(I am not sure on that.)

 

My tech took my belt off and ran the motor for a short period in order to diagnose a bad belt tensioner. Good luck finding the problem.

 

Perfect, that's the exact reason why I'm thinking of doing this.

 

I would advise drawing a very detailed diagram of the proper pathway for the belt. It's easy to reinstall it incorrectly when you think you have it right.

 

Yes, I took digital pics when I was loosening it.

Does anyone know of a trick to get it off completely? I've seen DIY articles, but they are for non-Turbo 996's. I currently am having trouble getting off of the water pump pulley. The shop manual isn't that helpful, basically telling you to untension it (I've done that) and then "take it off". I've gotten it off of everything (the power steering pump, the idler pulleys, alternator pulley, etc.) but can't wiggle it out from around the water pump pulley.

 

You have to twist the belt over on ltself a little and tug pretty hard on the part to the right of the pulley and drag it to the left. It's hard to explain but you're nearly there. The last part to come free will be underneath that far left lower pulley