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Discussion Starter #1
I have searched high and low and all I get is conflicting data and my Chilton’s manual is worthless (in this and many other things). I’m finding 40-60 psi hot @ 2500 rpm’s, 40-60 psi @ 2000 rpm’s, 40 + @ 2500 rpm’s, etc. While all of these should be sufficient oil pressure for the engine, from a diagnostic stand point, it’s not a clear indicator of engine condition.

I know my pressure is fine (5w30); 80 psi cold idling, 35 psi hot idling, and 75-80 psi hot @ 1200 rpm’s +.

However, since my engine is about 50 miles short of 161k and has 75-80 psi at driving speeds, how does this compare to new or a lower mileage engine? Surely the bearing clearances in the engine are not what they were, so knowing this information could be a good indicator of engine condition.

Does anyone know what the actual oil pressure should be? If not, how about posting what your oil pressure and mileage is if you know.
 

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I have searched high and low and all I get is conflicting data and my Chilton’s manual is worthless (in this and many other things). I’m finding 40-60 psi hot @ 2500 rpm’s, 40-60 psi @ 2000 rpm’s, 40 + @ 2500 rpm’s, etc. While all of these should be sufficient oil pressure for the engine, from a diagnostic stand point, it’s not a clear indicator of engine condition.

I know my pressure is fine (5w30); 80 psi cold idling, 35 psi hot idling, and 75-80 psi hot @ 1200 rpm’s +.

However, since my engine is about 50 miles short of 161k and has 75-80 psi at driving speeds, how does this compare to new or a lower mileage engine? Surely the bearing clearances in the engine are not what they were, so knowing this information could be a good indicator of engine condition.

Does anyone know what the actual oil pressure should be? If not, how about posting what your oil pressure and mileage is if you know.
Oil pressure is in the "NORMAL" range just past 12 o'clock. My car has about 220,000 miles.
 

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160k miles is nothing for these engines if driven sensibly and maintained properly.

80psi at cold start is very good. Down to 40 when warm at idle is good too. This is based on my experience with a 2012 car from another manufacturer, with a two-stage oil pump that varies between these two pressures depending on various factors.

Back in the day the rule of thumb was 10 psi for every 1000 rpm, but back then an engine that ran 100k miles was worn out.
 

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Discussion Starter #4
Thanks for the responses Dneli and Yadkin!
 

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The oil pressure guage on these mustangs are idiot guages. If it is over 6psi or something it will say good pressure so thats not a good way to tell.

As mentioned, those pressure are normal. A better way to determine engine health is a compression test and a leak down test if needed. Start with a compression test. 161k is high but nothing out of the ordinary for a modern vehilce. My 2V has 162k and doesn't burn any noticeable oil and runs like a freight train (in its own slow,humble, 2V kind of way :) ).
 

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Discussion Starter #6
Thanks JonR2006!

I know a lot of people do compression checks, and I do as well, but only to pinpoint the bad cylinder(s). I prefer a vacuum test. Yes I’m old school! Since an engine is really nothing more than a big ole air pump, a vacuum test can tell you more than if you have bad compression… ie bad valves, valve guides, valve springs, head gaskets, rings, intake gasket, vacuum leaks, clogged exhaust, etc. Not only does it tell you more, it’s a 10 minute test versus something that normally takes several hours and only tells you that you have normal, low or no compression.

I have ran a vacuum test and those aspects of the engine are great. Since I know this part of the engine is doing as it should and shows little to no signs of wear, I was curious as to what oil pressure for this specific engine was. Since bearing clearances increase with wear (decreasing oil pressure), oil pressure can be used as a gauge if you have enough data to compare. Unfortunately oil pressure data on this engine seems non-existent other than an “acceptable range”… and even that seems to vary. Yes, it appears to be my pipe dream!
 
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