05 chevy tahoe 5.3l v8. I bought the car it was fine.
Started getting low oil pressure. Then it started
ticking. Since it had over 300000 miles on it we
decided to do a engine swap. Got the new engine
put in. Everything seemed fine then all a sudden
getting low oil pressure again. Put a new oil pump
on it. Car ran fine. Then once got warm it started
dropping pressure again. And also started ticking
again. Found out there's a screen that sometimes
get blocked. Well this one already missing the
screen. Took out oil pressure sensor and started
the truck up. It shot oil out and some sludge.
Thought had it fixed. Ran it today did fine in the
morning. Had above 25psi. Drive this afternoon
when warmer was going fine then dropped down
to nothing with low oil pressure warning and
ticking back. I need my car running again
I have the same car. Same problem. Ended up just changing oil pump. The ticking you hear is probably your lifters. Enough oil is not getting in with the erratic pressure and they’re not lubricated. Dealership told me I needed to replace the lifters for $2500, I said “well potentially if I replace the pump and get the pressure back to normal, the ticking could stop, right?” They agreed. And the ticking did go away once pump was replaced. And if you haven’t don’t do already, may want to change out the water pump while your at it. Since someone will already have it accessible changing out the oil pump.