Poor cooling from the air conditioning may be caused be leaks from the AC cooling lines at the AC compressor. Inspection of the system is recommended to isolate any potential leak.
1990 Saab 900 Problem Reports
Newest 1990 Saab 900 Problem Reports
Oil commonly leaks from the distributor o-ring requiring replacement of the o-ring. Oil will be visible on the front of the engine near the distributor.
The head gasket can fail causing the coolant and oil to mix in the engine, and external leaks. Symptoms can include overheating, white smoke from the tailpipe at start-up or acceleration, and the visible presence of oil in the coolant expansion tank.
Oil can leak from the oil pump cover seal. Oil will be visible at the bottom and rear of the engine. The seal will need to be replaced.
My 900 turbo had an issue where the sunroof drains would get clogged with leaves and other debris, causing water to leak when it rained and the interior to flood. Upon some research and talking to other owners, I learned this is pretty common with this model. Using compressed air, you can put the nossel up to the drain and force air through the drain duct, thereby cleaning it out.