yup, GM minimum specs for oil pressure. Kinda makes ya wonder why they set them sssooooo low

 

Because technology has improved over the past years and a lot of the newer engines don't need high oil pressures. Tolerances have gotten a lot tighter and you don't need as much pressure to keep parts from touching each other.

 

Not all 5w-30s are the same viscosity and in some brands the 10w-30 can be thinner than 5w-30 at operating temps. 30weight is a range not a specific measurement.

 

I agree. 18 psi @2000 rpm as stated above would concern me. My worn out LT1 with 138k on it didn't have pressure that low.

92/95TransAm, you say you have 10-15 psi at idle and 60 psi on the road. 15 psi at idle is acceptable, 10 psi on a fresh motor is kind of weak. 60 psi on the road seems fine. I was told to look for 10 psi/1000 rpm, and with my stock motor it was doing just above that. Showed about 65 psi @ 6200 rpm.

I think when you switch to 10w30 you'll see a little increase in pressure. If for some reason your are running Mobil 1 5w30 then be aware that it is on the low end of the spectrum for a 5w30- it's almost a 5w20.

 

sorry to jack but since its pretty much the same question and there are already soo many other threads on it here we go

my oil pressure has been pretty retarded lately ,

when cold startup it i will be around 45-50 , when it warms up it will steadly drop , hotter teh car gets the less the pressure is
at idle its usally around 18-20psi ,
with 160* thermo the car is usually at about 170-185* but since my fans are not programmed for it when sitting there or constantly driving hard the temp will rise to about 220* and at idle my pressure will be around 10-15psi maybe even less sometimes,
at WOT the pressure is around 40-50psi
cruising its around 40psi

i know lt1s do usally have a problem with low oil pressure but lately its been worrying me

at 77k what could it be ,
did the pickup fall off, could it just be the sensor or my sending unit going bad

2 times in 3 months while driving hard making a left hand turn my oil pressure dropped to 0 and teh check guages light came on , rev it up and it would go back to normal and i use 5w-30

 

Those pressures sound fine for a bone stock LT1. With the original stock motor at 160k miles, it would drop to 15psi at 650rpm when at 210deg.

The loss of oil pressure simply sounds like uncovering the pickup....no baffling, dipstick is wrong, low oil level, etc. Something you will have to investiagate.

 

i think sometime in the near future i will be dropping the pan anyways to investigate

 

I work for a GM dealership. According to their guidelines, this IS correct. It does sound low, but these engines tend to run lower pressures than most rebuilt engines. I would be concerned on any engine I built if it only had this much oil pressure, but GM isnt.

 

umm first of all get rid of 5w-30. Put some good 20w-50 or 15w-50 and call it a day.
My new motor seemed to have low pressure to me (+/-20psi) as well when i put offbrand 10w-30. I put some 20w-50 per my engine builder recomandations and now i get around 23-25 psi at hot idle which is more then enough for these engines. At 2rpms i have around 45-50 psi.
Marcin