This problem is driving me insane! Initially the car, 1999 SAAB 9-3 convertible FSP/HOT (T5, 200HP engine, stage 0), had initially a intermittent blinking oil pressure light. This should be fixable, i thought. Well that seems to be for the untrained eye. After the initial problem with the original engine the problem as resurfaced again even when the engine has been replaced.
- Oil light intermittent while idling.
- Balance chain cut by the SAAB dealer (chain links found in the sump)
First diagnosed and tried to fix the problem on the original block:
- Pulled the sump of the car
- Cleaned the clogged oil pickup strainer
- Replaced oil filter (genuine GM, partnr. 55560202)
- Replaced oil (genuine GM, partnr. 93165557, full synthetic 5W30)
- Replaced oil switch (partnr. 9112459 )
Driven for 2000 km without a oil pressure light lighting up (anxiously keeping an eye on it) and all of a sudden the oil pressure light came on. Directly pulled the car over to the shoulder and called a tow-truck for expedition.
- main and rod bearings totally worn
- found ‘copper flakes’ in sump
- crankshaft bent
So i decided the replace the bottom part of the engine.
Engine replaced and overhauled:
- Sourced a B204 turbo engine (bottom part with crankshaft and pistons)
- Thermostat kit, genuine GM, partnr. 30577561
- Cylinder head bolts, genuine GM, partnr. 5955794
- Front oil seal crank, genuine GM, partnr. 55557231
- Rear oil seal crank, genuine GM, partnr. 55557240
- Gasket cylinder head, genuine GM, partnr. 9185695
- Gasket exhaust manifold, genuine GM, partnr. 55557285
- Valve stem seals, genuine GM, partnr. 5955570
- Timing and balance kit, genuine GM, partnr. 93184480
- Turbo charger full fitting kit, alternative, partnr. 21349999
- Exhaust manifold repair kit, alternative, partnr. 21347280
- Timing cover, genuine GM, partnr. 9542622 (used but in good condition)
- Pressure relief valve spring, genuine GM, partnr. 9309998
- Pressure relief valve, genuine GM, partnr. 9167784
- Replaced the timing cover
- Replaced the oil pump gears
- Replaced the oil pickup seal
- Replaced the oil transfer pipe seals
- Replaced the pump cover seal
- Flushed and cleaned the oil cooler
- Replaced oil cooler seals
- Replaced oil filter (multiple times already)
- Exchanged oil thermostat
- Cilinder head, before fitting the head has been milled to make it straight flattened again.
- Turbo, Garret T25
- Oil cooler (flushed and blasted clean with 8 bar air)
- Oil filter housing
As the – timing and balancing kit – didn’t include the correct sprockets for the balance rods i decided to leave the chain off, left the rods in the engine and placed a blanking plate under the balance chain tensioner to avoid possible oil leakage.
Mounted everything together and measured, using a mechanical pressure gauge, to see if the pressure was stable. After running the engine to a normal operational temperature everything seemed fine. While running idle the oil pressure measured ±2.1 bar.
Argghhhh, not again!
Took the car for a test drive. After 15 minuten, engine heated up again to normal values and at the traffic light i noticed that the oil light was flickering again. However when touching the gas pedal for just a little bit the light went off.
So the while idling the oil pressure dropped from the idle ±2.1 bar to a minimal low point at ± 0.55 bar but did rise again while revving the engine. So seems as the visocity changes the problem arises.
As i have added a sandwhich plate between the engine and the oilfilter, i can read the values from the Equus oil pressure gauge, which ranges from 0 to 7 bar.
Got the engine back into the garage again.
Now what? Now i am completely lost at this point.