What would cause 92 gmc sonoma 4.3 to knock and oil pressure to fluctuate and drop as it heats up?
Engine started to knock and drop oil pressure. Knock speeds up as You
accelerate. The oil pressure starts out fine and then flucuates then drops as it
heats up. Cant decide if its a rod a bering a stuck lifter or the oil pump. Engine
has 150k miles.