2001 Yukon xl
My oil pressure gauge goes from 40 to zero
while driving and makes a knocking noise
but when I first start it holds pressure to 40 I
soon as I step on da gas the meter waves
It could be the oil pressure sending unit, or the oil pump itself.
If you here knocking it wont be a bad sending unit,you have a bad oil pump.
Yep oil pump, don't continue to drive it you will wipe out the engine if damage hasn't already been done.
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