BlueTA99

hey guys was up! i have a 1999 Trans Am (Non-WS6) 6 speed manual transmission, i bought the car with no engine, so the chassis has around 98,000miles on it, n the engine i put has lil above 60,000miles, the engine that came from another 1999 trans am that it was in wreck (from the back) n the engine was running good! he is my friend so i driven his car before... so back to my problem...

everything is stock nothing is done to it but a regular K&N filter, other than that it is bone stock from the factory...

lately i been having an oil pressure problem...

at cold start the oil pressure is well over 40 ( im guessing 50 since its between 40 and 60)... n thats always at a cold start

now when im driving n warmed up, the oil pressure is at 40 (while im crusing)... but then after a little while, when im at a complete stop the oil pressure starts to drop little by little n the needle starts reading the oil pressure around 35 n then goes back up like 38... n then sometimes the needle starts bouncing from 35 to 39 back and forth... when i start from 1st gear (regular driving) the oil pressure goes back up to 39-40... now lets say im doing 2500rpm on 3rd gear then i press the gas pedal half way i accelerate n it goes up to 4000rpm (still in 3rd gear), the oil pressure barely goes a little above 40...im guessing around 41-42 (i know its no more than 45)... and on top of that while reaching 4000rpm it starts to make a rattle noise (maybe my lifters or something from the valvetrain but i could/can be wrong)... the noise is pretty loud, i could hear it from inside with windows up and down and is very annoying and personally it hurts me hearing that noise cus i feel that im screwing up my Trans Am n now im afraid of going above 3000rpm...

but despite the noise n the oil pressure drop, the car is doing perfectly fine, i use my Trans Am as a daily driver to go to school and work n do erins, as long as i drive regular the car is good

i recently change my oil like a month ago n i use Valvoline Premium Motor oil 5W30 (n right now im thinking of switching to synthetic, or recommend me something else) there is no leaks at all, i check my dipstick once a week n theres no drop...

i use Premium gas 93 octane

and here r the list of things i have changed last year...
*Exhaust gaskets 2X
*Water pump
*Thermostat
*Oil pan gasket
*Front Seal
*A/C Tensioner

so please i need help, opinions, advices, facts, suggestions or anything else please let me know...

i thank you and i really appreciate you for taking your time reading this.

1FST-Z

iTrader: (6)

Hey dude,
Nobody has replied to your post yet, so I figured I'd give you a shout. Not much advice to give, except that anytime you're at WOT, your oil pressure should spike up above 40 psi. It's what is considered "normal" for the LS1. I don't really know anything about oil pump situations, etc...so perhaps someone else will chime in and tell you if you perhaps have a failing oil pump or sending unit or something.

Blackhawk777

Alot of what it's doing is completely normal from my understanding. The rattles you may want to check out. Could be a loose exhaust shield.

blubyou02

iTrader: (1)

I would have an experianced mechanic close to you that has a good rep check it out cause it sounds to me from what you are describing it could be main bearings need replaced could be why your oil pressure fluctuates so much and the rattle noise at 4000 but i could be wrong. Good luck in what you find out.

rk_2000_Z/28

iTrader: (3)

35 pounds at warm idle is still very much in the acceptable range. I would have the rattle checked out though.

BlueTA99

is it normal really? cus the rattle noise only happens when the oil pressure starts to drop... so thats y i was assuming that the reason for the noise was bcus of low oil pressure

BlueTA99

well the noise only starts to come when it starts to have low oil pressure... but then again, the reason it starts to lose oil pressure might b bcus of the main bearings...