crzhrs

iTrader: (11)

My truck 2000 2500 with a 6.0 has no oil pressure at cold startup. I have to rev the engine to bout 2000 rpm's and it will get up to 40 psi. It started this about 3 or 4 weeks ago. At first all I had to do was rev it then let off the gas and it would stay at 40 psi. But now I have to hold it at 2000 rpm's until it reaches bout 190 degrees for the pressure to stay at 40 psi. If I let it idle before it reaches bout 190 the pressure drops to almost nothing. I know it is NOT the gauge cause I can hear the valves ticking when the gauge shows the pressure drop. I have not heard any bottom end noise so I was wondering if something is blocking off a passage or ? to the topend of the motor. Yes I know that this is backward from how oil pressure normally works. It should have pressure when cold and lose it when hot.

Anyone want to take a stab at it?

blkbird

iTrader: (28)

Pump is probably going out.

madclown

iTrader: (4)

I would also suspect the pressure relief valve in the oil pump. Replace the oil pump.

JPH

iTrader: (2)

I would start here, and replace/inspect o-ring also.

crzhrs

iTrader: (11)

I forgot to mention the truck has 253,000 miles on it. I do not have the time or money for a rebuild right now... so is there anything else I need to change while I'm doin the oil pump. Timing chain maybe?

JPH

iTrader: (2)

t/c set for sure man.