1999 Saab 9-5 4 cyl Front Wheel Drive Automatic 131000 miles
I have a 1999 saab, 9.5, 2liter turbo. The heater bypass valve was replaced 4 months ago (the start of everything). Then, about 2 months later, the turbo has gone. The garage replaced the turbo, dropped the oil pan, cleaned the pick-up tube and screen (which had a lot of sludge). Then when run, the oil light would come on after the engine warmed up. The oil sending unit was then replaced, but typically after about 20 miles of driving and coming to a stop, the light comes on. When you increase the rpm by about 2-3 hundred, the light goes out. It runs very well, sounds good. There is a little blue smoke, but the mecvhanic says that is left over from the turbo failing and oil getting into the exhaust
You can always use an oil pressure test gauge. Figure 10 PSI for each 1000 RPM.
February, 9, 2008 AT 5:34 PM
The pressure when idling checks out just fine with a manual gauge.
February, 10, 2008 AT 7:56 AM
You may have slightly worn bearings, try a slightly heavier oil. 25-50 should do it.
February, 11, 2008 AT 11:32 AM
Well, I changed the oil with synthetic 20-50. Ran it about 15 miles, came to a stop sign and as the rpm decreased to 1500, the alarm and light came on. Brought the RPM up above 2000, and the alarm and light went off. But the more I drove it (I had to get home--1 mile away), the more I had to increase the rpm to keep the alarm and light off. When I got home and turned the care off, I turned it back on about 1 minute later, and everything was fine.
ANY other ideas?
February, 11, 2008 AT 12:21 PM
You say after turning it off and then restarting it, it ran with no lights or buzzers? I gotta tell you, if you used a pressure guage and the pressure was 5-10 psi at idle with warm engine, you may have a wiring or sending unit problem. I need to go out right now, but I will look into the resistance values for the circuit. Get back to you!
February, 11, 2008 AT 12:43 PM
Some testing info
June, 11, 2008 AT 10:09 PM
Sorry to say but you still have sludge in your eng which as gone down & re-block your oil pick up screen again, will need to clean eng more extensively & check conrod bearing while you are there.