Where'd you get this info from? Not trying to knock it at all, its just an interesting bit of info.

Also, don't the VVT/DOD engines have a bleeder in the pan set at 45 psi?? So even at max rpm they would only get 45psi providing the bleeder can drop all the pressure...

 

I have heard the same from a few engine builders.

 

agreed. it was just that you stated oil pump oil ring only in your previous post that made me post that. basically on the same page just saying there are more things than just the oil pump pickup o ring that could cause it.

at the same time im just saying I would question the guage more than the engine on this issue

 

Old oil at operating temp is thinner than new oil. My car idles at 25 psi in the heat of summer (old oil). My oil pressure goes up to 60+ at high rpms so I have no worries.

As stated earlier, 10 psi per 1k rpms is all that is really needed.

What brand/weight oil/oil filter are you running?

 

That's really low.

I put in a ported oil pump and just changed the oil. I have 60psi at idle.

Check the pick-up tube o-ring, if it's not that, it won't hurt to change the pump to a ported one. Mine's MTI.

 

You probably have the high pressure spring in the pump, you results are far less average than the OP's so its not a good comparison. His is not "really low" by any means whatsoever. Its actually in line with average.

 

I never said I was average...but

I'd go with a ported one since you are already tearing it apart to check that o-ring.

 

I just had this problem this weekend.

I changed out my oil, filter, and it was still the same. SO I switched to an LS6 oil pump and replaced the O-ring. now I have around 35PSi at idle.

 

People get too caught up on oil pressures. Most people will tell you that 10psi per 1k is within spec. And that's true to some extent.

What you need to really pay attention to is oil pressure fluctuation, both short and long term.

If your pressure for the past two years has been 40psi hot idle, and one day all of a sudden its 25psi hot idle, sure that's within spec technically, but chances are that there's a problem. Your oil pressure should not increase or decrease dramatically ever.

You will tend to lose a few psi when you swap to a bigger cam, but nothing dramatic. Other then that, no.

 

I believe the sevice manual states that 7 psi hot idle is within spec, hold on I'll get it out and check it.

ok, right from a 2002 firebird service manual oil pressure hot minimum specs (5.7) are

1000 rpm 6 psi
2000 rpm 18 psi
4000 rpm 24 psi

although these are specs, Id say to watch for dramatic changes as said above.

 

Someone needs to explain this one to me... I may be new around here but have been wrenching on small and big blocks for too long and this just plain doesn't make sense. Pressure is RESISTANCE to flow. If you noticed an 8psi increase then that K&N filter is more restrictive. If I'm wrong, please explain.

 

Its not the filter, its the oil itself. I always notice a slight increase in pressure after changing the oil and thats using various oil filters, but the increase is always the same, just a few pounds. Im no oil guru but if I had to guess I would say its because the old oil suffers viscosity breakdown which in turn makes it thinner, and reduces the resistance to flow.

 

That much I understand BUT he said his oil filter made his PSI jump... so I was assuming (probably) incorrectly, that he just changed his filter to do this experiment between K&N and AC???

 

Think about this. Your oil pressure sensor is on the top of the motor behind the intake, your oil filter is on bottom of oil pan. If it's reading a higher psi, it's getting a higher velocity of oil shot up to the sensor..

 

Pressure is/should be pretty uniform everywhere in the system. If I put a restriction in an oil galley somewhere, this will cause pressure to rise everywhere. His claim to 8psi increase in pressure by adding a K&N oil filter just tells me that either K&N filters are restrictive (causing pressure increase) or his method of testing is at fault. Either way, more pressure isn't exactly a good thing. Pressure, or PSI, is just a way of measuring restriction. The more pressure you have, generally, the less flow there will be. It's a balancing act.

 

Unless the goo you are pushing through a hole is thicker than the last goo you tried to push through it. I dont know I would have to see a diagram of the oil passages before actually assesing it. But if the sensor is after the filter... you would see a loss if the filter was restrictive, I am agreeing with what you are saying overall, my opinion is it was the oil not the filter, which is what I feel when I change my oil/filter and see the pressure go up. I did at one time get in a bind and use a no name oil filter from a Kwik Kar I was a Tech at for a little while and saw the lowest pressure I ever had, that came off real quick and went to the A/C Delco.

Also FYI for anyone, I went to autozone not long ago and opened all the oil filter boxes in all brands for an F body, inspected the holes by the seal and the holes in the filter element retaining barrel inside the filter, the A/C delco put them all to shame as far as how many perforations or corrugated the barrel was with holes and also that it had a steel barrel, one filter had a plastic cage it looked like a real POS. And as for the holes up by the seal, the A/C Delco had more holes than some filters and larger holes than pretty much all others so it should actually flow best. Its construction just flat looked the best overall.

 

First make sure the psi rise with rpm like it should. If there is a bad o-ring the psi will rise then fall while holding at a higher RPM.
While the engine is running check the dipstick. If it has a couple tiny bubbles on it the pickup tube o-ring needs replacing. This happened to me about 3 weeks ago after a head cam swap. I forgot to replace the old o-ring and I got about 15-20psi at idle. Replaced the O-ring and get about 32 at idle with no bubbles on the dip stick. Weight oil and oil filter can make as much as a 15psi difference. Another personal experience.

 

Thats not true, the oil pressure is read AFTEr the oil filter SO the higher the pressure reading the LESS restrictive the filter. The fram oil filters are more restrictive because they FILTER MORE and of course this costs you oil pressure. The KN filter filters less so it flows more.......simple really.

 

Do these LS engines have a oil filter relief by-pass like the older engines did on the filter adapter?

As for the Fram filter, I think they have a built in by-pass valve.

 

My oil pressure used to be like that, till I fixed my pvc problem. Do this, start the car until it warms up, and while running take the oil cap off. If there was a suction on the cap, then you have something blocked off wrong, if theres no suction, then your fine but then chances are you oring is pinched instead.