Hi, I love your show.
I have a lovely Saab 9000 cse turbo and it drives beautifully except for a few minor issues. 1. There is a small oil leak (a few drops a day). Mechanic can’t pinpoint exact location and suggests we wait a while before diving in. 2. The display has some glitches. Gas gauge works erratically, dash lights are perpetually set to night time mode.
Car gas 150,000 miles.
Ah, finally something I have a lot of personal experience with...
Same car I've had as a daily driver since 2011. Mine has 365K miles and still going strong. In fact just a few days ago I had my Tech2 hooked up to the car to program a spare remote and for grins checked the fuel trims - short term was 0% and long term 2.3%. Not too shabby considering the fuel injection system has never been touched aside from replacing the fuel pump.
The engine is an evolution of a Triumph design, and while most of the Britishness was engineered out when Saab brought the engine in-house they do still have a tendency to mark their territory. Probably the best way to locate the leak is to add some UV dye to the oil as Scotty says.
One place 2.3 engine likes to leak is the front driver-side corner of the engine from the head gasket. (Driver-side in the U.S. and other places where we drive on the right side of the road.) This is due to the head bolts loosening up over time. The factory fix is to retorque the head bolts. You can also elect to replace them, they are stretch-to-yield bolts and really should only be used once. (Fortunately this is an external-only leak.) If you have this leak the Saab TSB that covers it is here:
http://www.townsendimports.com/Saab_TSB_Folder/Saab_TSB_pdfs/210_1704_utg2.PDF
(The above is for the 2nd-gen 900 but also applies to the 9000.)
Electrical glitches are frequently caused by bad solder joints. I've reflowed quite a few on mine in the past. Bad grounds will also cause issues. Your fuel gauge problem may just be a bad connection to the instrument cluster. As you may be aware, it is fairly easy to remove the entire top of the dashboard to gain access and you can easily reseat connectors on the cluster. Of course it may also be a problem with the sending unit in the gas tank.
Dash lights may just be burned out after 25 years. I've had to replace several bulbs in mine over the years. Once again, it is pretty easy to access the instrument cluster on these cars.
The parts situation is not quite a dire as Scotty indicates since the Saab Parts company (now Orio) was not included in the company bankruptcy and is still a going concern. There is no denying though that some OEM parts will not be available. Also the 9000 was already quite old when the company went under and some factory parts were already unavailable. In some cases used parts may be needed, and there are even some things I've ordered from overseas sources.
Bear in mind that these are specialty vehicles that did not sell in huge volume and most mechanics don't know much about them. Here are some resources to help:
https://www.saabnet.com/tsn/bb/9000/
https://www.saabcentral.com/forums/9000-workshop.17/
https://www.saabscene.com/forums/saab-9000-1984-1998.106/
http://saabworld.net/forumdisplay.php?f=6&s=33d009e3eb6acf9035de5f8360cea9a5
https://www.saablink.net/forums/car-problems-saab-9000-only.52/
http://jope.fi/saab/www.quasimotors.com/
http://www.townsendimports.com
http://z90.pl/saab/pdf/9000wiringdiagrams.pdf
https://www.youtube.com/watch?v=MOjXpJkgn-I
Well good luck finding parts for that stuff. Company went bankrupt a long time ago. As for the oil leak they're easy to find just put some UV leaked into the engine oil then see where it glows out using a UV light and yellow sunglasses. As for your electronic problems those are known for that often the dash units themselves start to break down and like I say getting parts of those things is near impossible in the states
Just noticed, looking at your display name if you are in Los Angeles you have an excellent Saab specialty shop available to you, "Your Right Solution" on 8664 Venice Blvd:
https://www.yelp.com/biz/your-right-solution-los-angeles