What is your oil pressure at when you are at idle after you have been driving..mine seems low, but want to compare?

 

15-20 when not under load.

 

what about when you accelerate? Mine is running about 115. To me that seems too high

 

Mine is around 30 under no load and around 90-100 under acceleration.

 

One strange thing I noticed. Before I switched to mobil1 and mobil1 filter, at highway speeds, I would be at a steady 60. now with m1 I am at like 70-80 .. whats that mean ?

 

Before my first oil change, I would idle really low at around 15-20 psi and at the highest it would never get past 60. Nowadays, if the car is cold or I am really letting the car go, it can get up to the max (120) which seems really high for me. On the freeway in 6th gear going about 80mph it sits around 65-75 which still seems pretty high considering I'm not going that fast or gassing the car.

 

can anyone shed some light to this subject? This can not be normal for a sports car! I dont wish to blow my seals do to a simple fix or something internally wrong.

 

The oil pump speed is dependent on engine RPM. The Z has a REAL oil pressure gauge, and it is normal for it to vary depending on RPM. My oil (Mobil 1) will start off @ 40-60 cold idle and go up to 120 @ 3000-4000 RPM, even with no load (just spinning the engine with the clutch in).

Once things warm up the pressure is more like 15-30 @ idle and 60 @ higher engine speeds. This is because oil gets less viscous as it heats up (and therefore flows more easily which reduces the backpressure).

-D'oh!

 

I know i should take it easy for the first few minutes. But when it goes to 120 should i be worried something will happen to the motor?

 

no - its perfectly normal

 

I just switched from reg. mineral oil to Mobil 1 after 2300 miles and I noticed a slight dif. in oil presure, maybe a 5% drop but nothing like what you guys are.
I say make sure you don`t have excessive / overfilled your crankcase, cause you know how tricky reading the dip oil gage is.
to much oil can be bad news.

 

When I turn my car on for the first time of the day my guage displays 60-70psi at idle. For the first 5 to 10 minutes if i just press the gas it goes to 70-80 then 120 when I hit the gas to merge with traffic or drive at 40 to 50 mph. After 5 to 10 min under normal freeway driving 60 to 70 mph, it is at 60psi. When I floor the gas, the guage displays 100 to 110psi. So it sounds like everyone is getting the same readings. I have a question about oil if anyone can answer. Is nissan Nismo oil any good? Or does anyone use royale purple?

 

i just changed my oil yesterday. only 2500 miles on the car but i just wanted to change it...not using synthetic just yet and i used an original nissan filter for now. i had thought i over filled some (put in 5 quarts) so i drained out a little less than half a quart. at idle it looks like the oil pressure is a little past the second mark (30-40 i guess) after warmup but when i rev the engine it goes past 60 to the next mark (around 90-100) i'm guessing. i'm not sure if it will get up to 120. i'm going to test that later. i'm using mobil one 5-30 nonsynthetic. my question involves taking an accurate reading of oil using the dipstick. should i check the level of oil after the engine has been running for a bit? should the engine be on while i check it? should i let it cool down before i get an accurate reading? Also, could overtightening the oil filter cause a high pressure and what are the effects of overtightening? i'm just a careful person and i don't want to harm anything. i drove slowly to work which felt wrong in my Z.
thanks to all and i love this place!

 

Worst case oil pressure will always be with new oil and filter at HOT idle. As long as it is above 15 psi!
Oil pressure increases as oil ages and get thicker from volatile portions evaporating.........

Conventional oil can lose up to 25% volume in stress test while best synthetics may only lose 10% by volume. This loss makes the oil test at a higher viscosity 30>40, etc so the pressure goes up.

With a dirty filter at some rpm the oil pressure will open the bypass valve. Also at some rpm [usually greater than 3,000 rpm] the bypass may open from just pressure differential alone!

Factory usually set design point above 75 mph with a new filter and new factory fill oil.

You will have to plot the pressure vs rpm accurately looking for the pressure deviation [a squiggle ~][this may only show a 4-5-6 psi change over a very narrow 200 rpm range] in the otherwise fairly linear increase in pressure with rpm.

If you drive for hours above this rpm point, the oil will not be filtered............why a good idea to always change the oil before a summer vacation or a long multiple day 12 hour trip at 80 mph...........every oil and filter will be different.

 

it doesn't help that i put 10W-40 instead of 5W-30...GEEZ!
guess i'll have to redo it again tonight and put the correct oil in there. good grief!

 

i started a thread just like this several months ago wondering if my oil pressure was too low at warm idle. some people here are posting thier results at idle before the car is fully warmed to normal operating temp & also reporting pressures with thier a/c on. these both effect the pressure greatly.......15-20psi at warm idle(no a/c) & 100-120psi at (high rpm) is perfectly normal with the z. i researched this & made phone calls to feed my curiousity & concern several months ago......

-justin

 

i drained my oil and put in 5W30 and idle is at 30 psi almost exact..perhaps a bit lower. and it rarely goes over 90-100 at high rev once the engine is warm. man i hate having to take that cover off the bottom of the vehicle just to get to the drain plug and filter...i've got it down pat now though...

 

Mine idles at 30 goes to 60 at cruising speeds and goes to about ninety with moderate throttle. You should'nt have the take the bottom cover off just reach in the big square hole cut around the oil filter and drain plug.

 

Has any1 used the oil cooling liquid (might be some type of oil itself) ? I saw it at AutoZone and it said it works for all types of oil and for n/a and turbo/SC cars. Description said you pour it in the oil tank after each oil change... Does that thing work ?

 

Careful about reving too high till the oil warms to at least 160F, as oil has very little lubricity till warm to hot! Also the bypass valve in oil filter will open feeding dirty oil to bearings with high pressure.

But those things only matter if you expect as new performance after 70-120,000 miles.