Oil Pressure Question

Nixon1 · 05-13-2003, 12:44 PM

On a cold engine, my oil pressure is around 45 psi After it warms up a good deal...maybe for 30 mins of driving..my pressure at idle is only right about 20 psi. During cruising, it's maybe 25-30. Seems on the low side to me. During the period of time where the engine is warming up, I observed the gauge once. Pressure builds up by about 10 psi, and then sharply drops off....builds up again, and drops back off again. I leak almost no oil except when I run it hard...I believe it's coming from the front seal. I hear it's a common seal failure. And I burn very little oil.. All in all, I go through 3/4 to 1 quart every 3000 miles. The motor's got 144,000 miles on it and it used to be run on nitrous, not to mention the condition I received it in...ahhck...so yeah, it's been beat six ways to Sunday. So my question is...is my oil pressure ok for the age and all....and also, what could be causing this pressure build and release? Unless it's the gauge malfunctioning. I know american gauge clusters seem to be terribly built. I've never had a gauge cluster on an American car, either GM or Ford, that completely worked. Camaro had a broken Tach. The Stang has a broken Speedo. Which is more important is anybody's guess...

Thanks guys.

juiceman · 05-15-2003, 11:18 AM

as a general rule an engine requires 10 psi per 1000 rpm. so if you only get 25 psi and it never goes up when you rev it then you have a problem. most likely bearings.

Nixon1 · 05-15-2003, 03:42 PM

It's at about 50 psi but only when the engine is cold. Warmer it gets, the more erratic and low the oil pressure gets. Usually it sits at the bottom line and during acceleration, usually doesnt go past 30 psi... Never checked it on the throttle...but the pressure stays very low. Someone told me all Fords run on very low oil pressure.... My friend's car registered 0 psi at idle....

That motor ran for over a year...still runs, just like total crap. He swapped it out for a C4 and a brand spanking new 302.

juiceman · 05-15-2003, 07:26 PM

invest in a real oil pressure gauge. fords dont inherantly run low oil press. most fords will run 30lbs at idle and 50-60 at higher rpm the stock gauges are not very acurate. running a motor at low oil press. is ok for a reg. driver but will cause probs. if you race it or run it hard. oh, and the press. drop is caused by the oil getting thinner as the motor gets warm. if you have consistent press. spikes even when motor is hot it could be from the oil pump press. bypass valve. which would basically mean you need a new oil pump.

Nixon1 · 05-16-2003, 12:04 PM

So you think the gauge might just be toast? Wouldnt surprise me.. I've owned this Mustang and a Camaro before it...both of them had horribly inaccurate/piece-of-**** gauge clusters. The Mustang has no speedometer..the speedo head is destroyed. The Camaro had no tachometer... So the oil pressure gauge is on an electronic sender right? Guess that'll be on my list of upcoming gauges to buy including the tach, WORKING speedo, and A:F gauge......

I have no spikes when the oil is warm...it just reads consistently low.

LX5liter · 05-17-2003, 11:06 AM

I agree with juiceman, get a real gauge. Whan I first bought my car I thought the oil pressure was ridiculously low as well, then I put a mechanical gauge on and it was 35- 40 psi at idle warm, 60+ psi cold.

05-13-2003, 12:44 PM	#1
Nixon1 Registered Member Join Date: Jan 2003 Location: Palm Bay, FL Posts: 432	Oil Pressure Question On a cold engine, my oil pressure is around 45 psi After it warms up a good deal...maybe for 30 mins of driving..my pressure at idle is only right about 20 psi. During cruising, it's maybe 25-30. Seems on the low side to me. During the period of time where the engine is warming up, I observed the gauge once. Pressure builds up by about 10 psi, and then sharply drops off....builds up again, and drops back off again. I leak almost no oil except when I run it hard...I believe it's coming from the front seal. I hear it's a common seal failure. And I burn very little oil.. All in all, I go through 3/4 to 1 quart every 3000 miles. The motor's got 144,000 miles on it and it used to be run on nitrous, not to mention the condition I received it in...ahhck...so yeah, it's been beat six ways to Sunday. So my question is...is my oil pressure ok for the age and all....and also, what could be causing this pressure build and release? Unless it's the gauge malfunctioning. I know american gauge clusters seem to be terribly built. I've never had a gauge cluster on an American car, either GM or Ford, that completely worked. Camaro had a broken Tach. The Stang has a broken Speedo. Which is more important is anybody's guess... Thanks guys. __________________ '91 Mustang GT 5.0 AOD Daily Driver Current stats: NEW 302 short block, E-303 cam (@.050, 220/220, .498/.498, 110 degrees), 1.6 roller rockers, Performer RPM heads (aluminum, 1.9/1.6, 60cc chambers), Cobra intake, Granatelli 75mm MAF, Billet AFPR, Equal-Length Shorty Headers, Off-Road X Pipe, Flowmasters, 4.10 POSI 13.73 at 103.8, ~2.2 60'

05-15-2003, 03:42 PM	#3
Nixon1 Registered Member Join Date: Jan 2003 Location: Palm Bay, FL Posts: 432	It's at about 50 psi but only when the engine is cold. Warmer it gets, the more erratic and low the oil pressure gets. Usually it sits at the bottom line and during acceleration, usually doesnt go past 30 psi... Never checked it on the throttle...but the pressure stays very low. Someone told me all Fords run on very low oil pressure.... My friend's car registered 0 psi at idle.... That motor ran for over a year...still runs, just like total crap. He swapped it out for a C4 and a brand spanking new 302. __________________ '91 Mustang GT 5.0 AOD Daily Driver Current stats: NEW 302 short block, E-303 cam (@.050, 220/220, .498/.498, 110 degrees), 1.6 roller rockers, Performer RPM heads (aluminum, 1.9/1.6, 60cc chambers), Cobra intake, Granatelli 75mm MAF, Billet AFPR, Equal-Length Shorty Headers, Off-Road X Pipe, Flowmasters, 4.10 POSI 13.73 at 103.8, ~2.2 60'

05-16-2003, 12:04 PM	#5
Nixon1 Registered Member Join Date: Jan 2003 Location: Palm Bay, FL Posts: 432	So you think the gauge might just be toast? Wouldnt surprise me.. I've owned this Mustang and a Camaro before it...both of them had horribly inaccurate/piece-of-**** gauge clusters. The Mustang has no speedometer..the speedo head is destroyed. The Camaro had no tachometer... So the oil pressure gauge is on an electronic sender right? Guess that'll be on my list of upcoming gauges to buy including the tach, WORKING speedo, and A:F gauge...... I have no spikes when the oil is warm...it just reads consistently low. __________________ '91 Mustang GT 5.0 AOD Daily Driver Current stats: NEW 302 short block, E-303 cam (@.050, 220/220, .498/.498, 110 degrees), 1.6 roller rockers, Performer RPM heads (aluminum, 1.9/1.6, 60cc chambers), Cobra intake, Granatelli 75mm MAF, Billet AFPR, Equal-Length Shorty Headers, Off-Road X Pipe, Flowmasters, 4.10 POSI 13.73 at 103.8, ~2.2 60'

05-17-2003, 11:06 AM	#6
LX5liter dude5l Join Date: May 2001 Location: Grande Prairie, Alberta, Canada Posts: 603	I agree with juiceman, get a real gauge. Whan I first bought my car I thought the oil pressure was ridiculously low as well, then I put a mechanical gauge on and it was 35- 40 psi at idle warm, 60+ psi cold. __________________ Good luck! Brad R. 1992 L.X. 5.0 coupe MODS: A few little bolt ons New Best time ...11.60 @ 128 mph @ 2000+ ft altitude. Rice Haters Club member #39 Users rides #2542

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05-15-2003, 11:18 AM	#2
juiceman Registered Member Join Date: Jan 2001 Location: ny Posts: 197	as a general rule an engine requires 10 psi per 1000 rpm. so if you only get 25 psi and it never goes up when you rev it then you have a problem. most likely bearings.

05-15-2003, 07:26 PM	#4
juiceman Registered Member Join Date: Jan 2001 Location: ny Posts: 197	invest in a real oil pressure gauge. fords dont inherantly run low oil press. most fords will run 30lbs at idle and 50-60 at higher rpm the stock gauges are not very acurate. running a motor at low oil press. is ok for a reg. driver but will cause probs. if you race it or run it hard. oh, and the press. drop is caused by the oil getting thinner as the motor gets warm. if you have consistent press. spikes even when motor is hot it could be from the oil pump press. bypass valve. which would basically mean you need a new oil pump.