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Oil pressure ... what is normal?
Posted: Fri Nov 06, 2009 10:40 am
by phr1$k37
Hi folks,
Oil Pressure. I pray and hope I NEVER ever see a oil pressure gauge with a needle in the "low" range.
That being said ... what is normal operating pressure?
My ride is usually around the 250kPa range. I think usually some where around 275-290kPa (I need to double check) when driving / on the throttle. Idle I am 250kPa (middle of the gauge) BUT some times it falls lower like ~240kPa after driving around for some time and then at idle.
I have tried searching on google for what normal operation ranges should be. Any ideas?
Re: Oil pressure ... what is normal?
Posted: Fri Nov 06, 2009 10:50 am
by kings-x59
A mechanic told me sometime back, and someone posted it here on the site a while (Socalli maybe?). Oil pressure should be about 10 psi per 1000 rpm. I don't know what the conversion factor is to kPa is.
[someone chime in here if I am remembering wrong]
At least you have numbers on your gage, mine's an idiot gage - just hash marks. I have no idea what the real pressure is. My pressure drops by at least 25% after the oil gets good and heat soaked.
Re: Oil pressure ... what is normal?
Posted: Fri Nov 06, 2009 11:12 am
by phr1$k37
I think there has to be a "base" PSI / kPA the motor sits at first ... because
10 PSI = 68kPa ... at idle I am 550-650RPM (the lower than 250kPa I report is when I around the 550RPM). I used this tool for the conversion: http://www.csgnetwork.com/presskpapsicvt.html
I have a ScanGauge ... heeh guess I should dial in the codes to get oil pressure.
Re: Oil pressure ... what is normal?
Posted: Fri Nov 06, 2009 3:38 pm
by Smiliesafari
The "Smilievan" has 50 psi cold. 45psi at operating temp and it will drop to 35 at idle. At 197,000 miles those are very normal pressures. More important than pressure is oil volumn. As long as there is a constant volumn then you are good. Back in the day (60's) normal oil pressure for a Chevy small block was 35 psi. in a new engine.
Re: Oil pressure ... what is normal?
Posted: Fri Nov 06, 2009 3:53 pm
by phr1$k37
Ah, okay that is ... better!
IDLE: 35 PSI = 241 kPa
Running: 45 PSI = 310 kPa
Cold: 50 PSI = 345 kPa
Now the question is ... is that normal? 
I note that my running and cold starts are much lower than yours... maybe because I am using synthetic 5w30?
Re: Oil pressure ... what is normal?
Posted: Fri Nov 06, 2009 3:55 pm
by Smiliesafari
That is correct. Synthetic's will give you slightly lower pressures.
Re: Oil pressure ... what is normal?
Posted: Sat Nov 07, 2009 8:29 am
by Cobra
phr1$k37 wrote:
at idle I am 550-650RPM (the lower than 250kPa I report is when I around the 550RPM).
550.... i never idle less then 650 and i mean NEVER (at least that i've seen) is that normal?
Re: Oil pressure ... what is normal?
Posted: Sat Nov 07, 2009 1:32 pm
by phr1$k37
Cobra wrote:phr1$k37 wrote:
at idle I am 550-650RPM (the lower than 250kPa I report is when I around the 550RPM).
550.... i never idle less then 650 and i mean NEVER (at least that i've seen) is that normal?
Yes ... 550 .. she will dip to 52x RPM At least that is what the ScanGauge tells me and when she does, VERY quiet and no power issue. Smooth idle.