CoreyZ/28

iTrader: (2)

Will the o-ring for the oil pickup tube that goes into the oil pump deteriorate on it own or would it only be damaged from the pickup tube being removed and not reinstalled properly? I ask because my dad just bought a 05 Envoy with a 5.3 and the oil pressure is nothing at idle and has a slight knock(bought knowing this) yet the oil pressure will rise to 40#'s with any amount of throttle. He was told the o-ring was known to go bad over time but I was under the impression that it had to be tampered with and reinstalled improperly to mess it up. Just trying to figure this out before we go through the trouble of replacing the o-ring and not solving the problem.

Tainted

iTrader: (9)

it could be pinched, it could have a small crack or tear in it as well. Rubber and plastic over time will also just begin to break down.

CoreyZ/28

iTrader: (2)

Also has 181k miles

chrisfrost

iTrader: (8)

Those o-rings generally, depending on what they're made of, black, Viton ????last 10 years or longer before dry rot causes them to crack and that is in Phx, Az where it gets a little hot .

gMAG

iTrader: (1)

I believe that with thousands of hot & cold cycles, that any sealing device, including gaskets & o-rings, undergoes wear through friction. Eventually, they no longer can adapt with the temperature, and that's when leaks occur.