Oil pressure drops down to 15-20 with foot on brake in gear don't know how long it's been like this at 60 mph runs around 40 psi mobile one is the only oil ever used i thought
that it was the oil pump but after reading something on this site i found that it's not the
oil pump but the engine is lose is this normal with 67,xxx miles the engine only needs 10 psi at idle is this ok

 

Did this happen all of a sudden or has it always been like this? That is what is most important. That pressure should be fine, I've seen lower at idle. If it just happened then you may have a bearing problem or the pump/pick up might be loose.

 

There's no problem here.

 

so I'm upgrading my stall friday and the guy doing the installation said that he might have to
replace some seal due to changing the converter or cam?? to replace the seal he will have to drop the
oil pan so while the oil pan is off should i change the spring on the oil pump and put a new pick up tube in ??

or is there no problem like Joe said

 

I imagine the mechanic is suggesting replacing the rear main while he's got the thing apart....not a bad idea.

As Joe stated, there is no problem here. I believe the rule of thumb is 10psi per 1000rpm. In addition, changing the spring will not affect the oil pressure at idle.

Put in the stall and enjoy it!

 

I know every one said no problem here but it's driving me crazy that the gauge is going crazy
turns out when the car is in gear with foot on brake it idle's at 600 rpm with 25-30 psi
1000 rpm at 38-40 psi 2000 rpm 45-48 psi
so why does the gauge move so much do i need to replace the gauge ??? all of my other
vehicles stay at about the same psi no matter what rpm

 

Sounds like your oil pressure sending unit might be a little flakey. Is the reading staying consistent at the various RPM? In another words, is it always "600 rpm with 25-30 psi, 1000 rpm at 38-40 psi, and 2000 rpm 45-48 psi"?

If anything, sounds on the high side to me(if the oil pressure spring is stock....). That's why I'm wondering about the sending unit.

 

when the engine is cold the psi is higher at all rpm when the engine reaches 160
degrees it reads a little lower but always consistent at different rpm levels

 

Oil pressure varies with RPM. Your numbers are normal. It's a positive displacement pump. The more RPM, the more oil flows. The more oil flows, the higher the resistance to flow through the oil passages, meaning pressure back at the pump increases.

Oil is thicker when it's cold. Again, it creates more resistance as it flows through the oil passages.

You appear to be looking for a problem where no problem exists.

 

Well, if you're convinced something is wrong after all the input to the contrary, just ignore the advice and start changing things. That was sarcasm...don't really do that. There is nothing wrong here and the oil pressure should not stay the same at all rpm as you say your other cars do...

 

I'm not saying that all my other cars have the same oil pressure at any rpm they all very a
few degrees but not 20 degrees

i know when the oil is cold it's thicker and the more rpm you give it the higher the oil pressure
the next time your driving something other than your LT1 check out the oil pressure and see
if it changes 20 degrees from idle to 2000 rpm's

 

My four cylinder five speed s10 does. It's normal. Actually a little better than normal. Be glad you car is not where mine is!! Tore down and in machine shop Hell!!!!!!

 

ok, it's not degrees, it's PSI (pounds per square inch).

I have three other cars/trucks that I drive. a 99 Corvette LS1. The oil pressure at idle, warm is 25psi on the gauge, 24.6 on the pcm readout. At 2200 rpm it's 46 psi on both. On my 2004 Chev Silverado with the LQ4 engine, i get 20 psi at idle warm, 50 at 2500 rpm. on my 2003 Land Rover Discovery I get 37psi at idle at 61psi at 2000 rpm.

As Injuneer said, the oil pump is a positive displacement pump and pressure WILL vary with engine speed. Again, if think this is abnormal in any way, then take steps...it's your car and your wallet. Start with the sending unit...top of the block behind the intake manifold, then the pump itself which is inside the oil pan. If you do replace the pump also replace the coupler between the drive shaft and the pump itself. You can also add a higher pressure spring to the pump to raise the maximum oil pressure achievable....

 

don't know why I said degrees ?? my truck at idle has 40psi and my explorer stays at halfway no mater what rpm so what i thought was a problem with my camaro is really a problem with
my every day driver the explorer the gauge stays at the halfway mark at any rpm so I'm assuming
that the oil sending unit is bad or is it the gauge ?????

don't be so sad about that rod bearing it just gives you a reason to make it faster !!!!

 

To check the gauge:

Remove the wire from the sending unit and do not attach to anything. Key on, gauge should read scale maximum.

Attach wire to good ground. Key on gauge should read zero.

If it does this it's fine.

To test the sending unit:

Install a mechanical gauge into the oil gallery using the plug on the side of the block above the oil filter adapter. Compare readings to the dash gauge.

Good luck