Saab (9-5) sludge issues: how bad?

If one were looking at early 2000's Saab 9-5 and/or anything sharing their line of engines, how prevalent are/were the sludging issues with these?

I know there was a retrofix but are the ones on the road NOW fixed or ready to pop?

Sludge was a problem with the I4, not the V6 (the V6 has its own problems). It's hard to generalize because there were so many updates to the PCV system, and some of them seem to have made the sludging problem worse, not better. The only way to really know what's going on is to pull the valve cover to inspect, and more importantly to drain the pan and scrape through the drain hole for evidence of sludge. IIRC there were some issues with the oil pump wearing prematurely as well.

The only ones that seem to have the problem well and truly solved were the late Aeros (post-2005 maybe? I can't recall the exact year) - the final fix involved adding an additional block vent somewhere down low, I believe.

If you find one already too far gone, the short block from a 9000 turbo is an upgrade. It's not a 100% bolt in swap, but it's close.

My friend that works at an all SAAB indie shop says that trick to keeping them sludge-free is making sure whichever pcv system you have is working, and frequent oil changes. His anecdotal experience is that early 9-5s do better with quality conventional oil and 3k mile change intervals than with synthetic and the long factory recommended change intervals. YMMV.

Personally, I'd hold out for a 9000 aero.

Sludging is a car-by-car thing, for a couple of reasons. Recommended oil-change intervals were I think 5k miles. Turns out that was too long an interval for a turbo engine and the capability of oils at the time. Owners who just followed the maintenance schedule in the owner's manual (or changed even less frequently than recommended) often ended up with more trouble than the ones who changed more frequently (the oil-changes-at-3k-are-cheap-insurance sorts, like me at the time). When I purchased my 9-5 I had a PPI done because of this, and mine was fine.

There were many PCV updates. IIRC, update 7 (the last one) was the best. My car had updates done as issued and again, no problem. Most of the examples that were going to have issues have already had them and the cars have since been turned into refrigerator cases and the like.

This is just an opinion, but I'd look only at 2.3s and if I was open to an automatic I'd stick with 2002 and later. That was the year a 5 speed unit replaced the 4 speed. There were some cosmetic and secondary system upgrades that year as well, like traction control and a smoother front fascia; Aeros got a sweet seat upgrade.

I really wish I still had mine; it was a 2002 Linear wagon with a manual. It got excellent mileage, had lots of torques and carried large dogs and furniture equally as easily. I replaced the 16" wheels with a set of 17" Klingons (older Aero wheels; Saab folks have a fun vocabulary to describe the various wheels offered). Once in a while I wished it had more swaybar but handling was generally very tidy, even as experienced by a guy who was coming out of various C4 Corvettes. These Saabs are comparatively light for their size, so while a 9-5 Aero would be ideal I'd have no problem with another Linear.

What Cones said. When I was looking I took along a straightened metal coat hanger with a little eye bent at the end. Stick it down the dip stick tube, scrape it around and see what comes up. My Aero had gotten the latest PVC update before we bought it with 100K on it. The car is now almost to 220K and is still going strong.