Any way to diagnose an IMS problem at test drive?
 

Is there a way to tell if there is an IMS problem with a 996 at a test drive? I know you can cut apart the oil filter to look for debris but that's not gonna happen when you meet someone to see their car. If they don't have records of cut apart oil filters or of the bearing being changed is there anything else to go on? Can you hear a pending problem with a stethascope?

IMS bearings fail without warning. You can measure cam deviation as part of a PPI. If the car checks out, negotiate in the IMS and clutch as part of the deal.

Agreed. Hidden time bomb issue unless you cut the filer looking for shavings, or have receipts for IMS upgrade or maybe even oil analysis reports. As to lore about IMS failings, frequent oil changes and higher mileage engines seem to have less issues than garage queens. I believe the class action lawsuit reported about a 10% failure rate issue.

Make the deal conditional on passing the inspection

Then either renegotiate based on what was found or walk away

So it looks like the short answer is no, as I thought. Thank you

The problem with diagnosing a pending IMS failure has always been timing; it could look perfect on Monday and make your engine a boat anchor on Wednesday….

I wouldn't consider a '98-2005 without a PPI from a shop that knows these cars. If an owner won't let you get a PPI walk away. Cutting a filter only gives you a half story I'd drop the sump, free oil change for the owner is cheaper than an engine.
Way more issues than just IMS, scored bores are a bigger issue here. Borescope, code check, manometer would also be on my list.