oil pressure drop once warmed up: Updated
 

after about 20-30min of driving, aka when the oil finally gets heat in it. I have oil pressure drop.
starts out cold at 40ish and builds like it should to 60+ and as its driven the OP gets down to 20 and will build to 30 but you can start hearing the top end rattle.

I put a "new" pump on it but who knows.
I do not think it would be the o-ring since it does have pressure till it gets warmed up.

Thought was to replace pump and if that doesnt help then I guess i will have to rebuild, URGH!

Is it a mechanical guage?

Ugh. I hate LS oil pumps.

iron block or aluminum?

its pretty common on the aluminum block motors, seems like most people say its the lifter bores heating/enlarging letting pressure bleed off.

i dont know, all LS motors make noise, if you hear one not making noise worry.....

is it a 6.0 that is stroked?

junkyard 6.0 iron block with mechanical gauge.

Fram oil filter??

What filter and what oil is in it?

This is why I didnt change my worn out timing chain. Gotta pull the pump to get the chain off and I didnt want to chance fooling with it with my bad luck. Maybe I could have made 375 HP if the chain wasn't worn out and retarding the cam 6-8 degrees lol.

Oil is Mobile dino oil and AC filter (I think). New GM pump purchased in Aug. I have original pump. Going to see if its covered under warranty.

URGH

Do you know the mileage on the motor? Could it be possible that the wrong weight oil is being used and the motor is just wore slap out? I have seen similar issues with the use of incorrect oil weight in combination with "loose" bearing tolerances. However, you wouldn't think that would an issue on a stock motor as long as it doesn't have 300k miles.

Unknown mileage from a 2001 Silverado. 5w30 in it.

My 5.3 has perfect oil pressure and it doesent tap at all.

the 6.0 in the 71 is quiet too. Love that thing!

Fixed it for you.

the iron block motors are alot quieter, my quarter million mile 4.8 is silent, but my LS1 chings and changs like every other one (garbage lifters?). oil pressure is a separate issue than noise though.

my first one made some lifter noise so it seemed. when i pulled it apart it had all wiped out cam bearings

Consensus is to put different oil pump on it and see??

Si

Contacting Scoggin D where it was purchased in Aug 2011 to see if they will warranty it, if not I will purchase new one from some place.
Could put the original one in it and see, that would be 'free'.....