It's not in my "Jalopies" thread, but I did post about it
here, my '99 Aurora in Diamond White Pearl. I had issues with that same display panel, but removing and cleaning some solder joints and connectors fixed it up. The biggest electrical issue was broken wires in the bundles going into the doors. Whatever those go to stops working, of course, and with the seat controls on the door panels, that's a
lot of stuff: seats, windows, mirrors, locks!
The paint on mine was killed by the previous owner keeping it outdoors under oak trees. That also fills the air intake for the ventilation system with debris that was quite a job to clean out. The car ran great, was powerful and smooth, expensive to run with 14 or 15mpg in town on premium, though. The interior was in excellent condition except for the panel above the instrument panel, which was pulling up at the front by the windshield. Everything power worked, once i got those wires spliced back together at the door jambs.
Seat memory worked, which is an issue in these cars, because the space under the drivers seat can fill with water if the sunroof leaks (very common) and destroy the seat memory module under there. I even found how to program the key fobs for seat memory; one key fob for me, the seats go to my position when I unlock the car, and the other key fob for her, and the seats go to her position when she unlocks that car.
I had to replace the fuel gauge sender, perhaps the one most common item on these cars. The wiper fingers wear out, and the gauge goes random when below half a tank. I also had to replace the idler pulley on the water pump belt. That failed some 40 miles out of town and AAA had to come get me in the middle of the night. You do NOT want to overheat one of these things.
I also had to replace the starter, which lives in the V on top of the engine, under the intake manifold. Not too bad a job.
Common engine failure in the early Northstars was head bolts pulling themselves out of the block, leading to head gasket leaks, power loss, and overheating. The repair is to install studs into the block and use nuts for the heads.
The other Northstar issue is they don't hold oil very well. The oil pan has not one but two joints onto the block, because of the baffle plate under the crank. Only one of those is gasketed, the other is sealed with a compound. The block splits at the crank, so there's another gasket-less seal there. The valve covers are HUGE, and don't seal very well, and one of the camshafts sticks out to drive the water pump at the rear of the engine. People have broken that camshaft trying to get that cover off without realizing the camshaft goes through it! Then there's the front cover over all of that DOHC timing chain system, with about 40-11 joints, gaskets, and covers. Finally, the aluminum used in the block is so porous that oil seeps through the "solid" metal! Over time, the exterior of the block gets slimy
from inside!!!
Hurricane Michael relieved my of my Aurora, whacked it pretty thoroughly by flying debris, and progressive gave me a ridiculously high check for it. Just as well, because the AC had just died and was going to have to be replaced. 😄
Aurora hot-rod tip, if you didn't already know. The only difference between the 4.0 Aurora engine and the 4.6 Cadillac engine is sleeved cylinders, and heads to match the reduced bore. Externally, the engines are
identical, down to every single mount, bolt, and connector. The ECU and tranny controller are identical between the engines. In other words, dropping a Caddy engine into your Aurora is 25 extra HP, maybe 50 if you have the VIN 'Y' Caddy motor. You change nothing else. Drop it in, start it up, and go quicker.