alright fellas this is what I have done. the truck has 176,000 miles on it. I just broke into the motor to put a cam in it. I put a new cam new oil pump mes timing chain and gears. and it started off at high rpms i would loose oil pressure. I would pull over and let it sit for a min and i would get all of it back. So i thought the screen was cloged. So I poured barrys chem dip down the dip stick tube about 3 quarts and let it set over night and then washed it out with diesel fuel about the same. and then put cheap oil it in. started it up and drove it around for a few days and oil pressure was great. then I did one more high rpm pull and it started all over again. and yesterday it just lost all oil pressure from start. so what are yall's opinion's ???

 

how was your cam lobes when you pulled the old cam? did you replace the o-ring on the pick up tube? if not thats where id look first honestly. you have 176,000 miles on that o-ring and you reused it. i doubt the pick up screen is clogged...i would drop the pan and see if you have room. also it could be bad cam bearings, but i doubt that without more info

 

my old cam looked good i thought but I will go look at it again. also I put a new o ring in it and it was an ported and shimmed pump from TSP.

 

also just went back and looked at my cam. no scaring or pitting in my cam. It looks as good as a 176,000 mile cam could to me.

 

how'd you install the oil pump? rolled it onto the pick up tube or loosened the pickup tube and walked it back into the oil pump? if you "forced" the tube back in u could have messed up the o-ring. also are you having a low oil pop up in that lil service box? check the oil sensor. id look into getting with someone tk scan your truck and make sure its not your oil sensor messing up. make sure its plugged in all the way too. we had a CAT D-6 dozer not run bc another mechanic didnt plug the sensor back up

 

well you can hear the motor loose oil pressure. I guess I am just going to have to take it out and tear it down. I bought another 5.3 short block that I have the heads off of anyway. so I might just go ahead and swap them out next time home

 

it sounds like your oil pump is clearing your oil pan of oil on high rpm pulls. Mine does it every once in a while since I did my high volume oil pump. Is the oil pump standard volume, high volume or what? Stock pans can be totally pumped empty by a HV oil pump

 

actually I dont know. the only part I know is it is ported and shimed. i thought about that too but now it dosent have any at idle either. so I dk. and I am almost scared to use the pump in the new motor.

 

oh man, if its doing that at idle my idea is ****, there's biggest problems. You're gonna have to pull it.

*could* be the pickup tube seal

 

hell idk but i am headed to work friday and in 3 weeks when I get back I am going to pull in and put another 5.3 in