Oil Pressure

[chucky]

Im working on a mod & need some info from those of you who have replaced your oil pressure gauge with a real one.

what is the average low pressure you see, say summer time running a synthetic 5/20 oil.


Thanks

[RF Overlord]

25 lbs idling in gear at a stop light. Mobil 1 5W-30.

[fastblackmerc]

25 lbs idling in gear at a stop light. Mobil 1 5W-30.
What he ^^^^ said. It could go close]r to 100 lbs when cold at higher RPMS.

[DEFYANT]

What he ^^^^ said. It could go close]r to 100 lbs when cold at higher RPMS.

Yup, what they said.

[Joe Walsh]

Warm oil on a warm day at idle....around 15-18lbs pressure.
Cold oil on a cold day at idle.....30+lbs pressure.

[Shora]

I don't feel to proud to admit it but I do believe that Ford decided to go with the dummy gauge for people like me. You see, I was never tought what is the correct oil pressure for this car (or any car for that matter). What should be considered normal and what not. If I replaced my gauge with a "real" gauge I wouldn't have a clue what to look for.

Wish there was a book "Marauder For Dummies."

[DEFYANT]

Warm oil on a warm day at idle....around 15-18lbs pressure.
Cold oil on a cold day at idle.....30+lbs pressure.

That seems kind of low..... Then again, your engine is a little different. What does your engine builder say is "normal"?

[Marauderjack]

Mine is around 15-20 PSI in gear idling on a hot day (Mobil 5W30) and about where the "Dummy" reads (60-65 PSI) at 2500 RPM cruise speed.;)

On cold startup it runs up to 90+ PSI for a few minutes when driving and idles at 50+ PSI cold.:eek:

Marauderjack:burnout:

[ROB502]

10 psi. per-1000 rpm with warm oil is fine.. So 5000 rpm needs 50 psi to not scald the bearings.:coolman:

[jdando]

20-25 psi during warm idle

70-90 psi during cold idle

I think we are seeing a trend.

jeremy

[RF Overlord]

Wish there was a book "Marauder For Dummies."There is...it's called mercurymarauder.net

As ROB502 said, 10 lbs per 1000 RPM is considered to be the rule of thumb, but that's going to vary by the design of the motor, and by its age. For the Ford 4.6L DOHC, those of us who have replaced the fake gauge have found that 100 lbs on a cold start and 25 lbs at hot idle are normal. Cruising along at 40 MPH, you'll see about 50-60 lbs...and so on. Once you know the normal operating parameters for a given motor, having a real working oil pressure gauge is a valuable tool that may one day (hopefully never) save your motor from complete destruction.

The biggest problem with the OEM fake gauge is that it reads "normal" as long as you have approx. 6 lbs of pressure or more...try driving down the interstate at 75 MPH for hours on end with 6 lbs of pressure and see how long your motor will last. With a real working gauge, you'd see the problem well in advance...

[Shora]

Quote:
<TABLE cellSpacing=0 cellPadding=6 width="100%" border=0><TBODY><TR><TD class=alt2 style="BORDER-RIGHT: 1px inset; BORDER-TOP: 1px inset; BORDER-LEFT: 1px inset; BORDER-BOTTOM: 1px inset">Originally Posted by Shora
Wish there was a book "Marauder For Dummies."


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There is...it's called mercurymarauder.net (TRUE! Thanks ya'll :D :beer: :banana: )

As ROB502 said, 10 lbs per 1000 RPM is considered to be the rule of thumb, but that's going to vary by the design of the motor, and by its age. For the Ford 4.6L DOHC, those of us who have replaced the fake gauge have found that 100 lbs on a cold start and 25 lbs at hot idle are normal. Cruising along at 40 MPH, you'll see about 50-60 lbs...and so on. Once you know the normal operating parameters for a given motor, having a real working oil pressure gauge is a valuable tool that may one day (hopefully never) save your motor from complete destruction.

The biggest problem with the OEM fake gauge is that it reads "normal" as long as you have approx. 6 lbs of pressure or more...try driving down the interstate at 75 MPH for hours on end with 6 lbs of pressure and see how long your motor will last. With a real working gauge, you'd see the problem well in advance...

So what should the pressure read at 75 mph? Only 20-30 lbs. because my RPM will only be betweem 2000-3000.

Also, I know that the oil is thicker when cold but can the pressure be too high? 100 lbs. sounds like a lot but than again, what do I know about the matter?

[JMan]

Quote:
<TABLE cellSpacing=0 cellPadding=6 width="100%" border=0><TBODY><TR><TD class=alt2 style="BORDER-RIGHT: 1px inset; BORDER-TOP: 1px inset; BORDER-LEFT: 1px inset; BORDER-BOTTOM: 1px inset">Originally Posted by Shora
Wish there was a book "Marauder For Dummies."




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So what should the pressure read at 75 mph? Only 20-30 lbs. because my RPM will only be betweem 2000-3000.

Also, I know that the oil is thicker when cold but can the pressure be too high? 100 lbs. sounds like a lot but than again, what do I know about the matter?

Hey Shora,
I was freakin' out about that 100psi at start-up in a thread a month or two ago also. I think that a really cold morning for us is in the 40's and to them it's in the single digits or worse. I just couldn't comprehend 100psi start-up pressure. That may be normal in those ambient conditions, I've just never experienced them. BTW, thanks for the cigars at the picnic, they were awesome!

J

[RF Overlord]

So what should the pressure read at 75 mph? Only 20-30 lbs. because my RPM will only be betweem 2000-3000.The 10/1000 is really more of a minimum...so as long as you have at least that, you're OK. The mod motor does have a goodly amount of oil pressure, so expect about 60 lbs at 75 MPH (with the stock 3.55 gears). Remember, the actual operating pressure also depends on the viscosity of the oil being used.

[Ozz]

I finished my gauge install Friday and changed my oil (5W-20 Motorcraft blend)... It's about 35 F hear and my pressure was:
90-95 at cold idle in park, 100+ (~105-110psi) off idle
15-18 at hot idle at stoplight in drive (550-600 rpm)
~40-45 at 40 mph (1100-1200 rpm)
~55-65 at 70 mph

So my range is a little bigger than some but I think it's still 'normal'... I wish it was a little higher at hot idle but perhaps it would be if I used 5w-30...

Is everyone running 5w-30? If so, why???

[RF Overlord]

Not everyone runs 5W-30. I switched because in the beginning I wasn't aware of how good Motorcraft 5W-20 really is and I believed the rumour mill that Ford only used it for CAFE reasons. If we hadn't installed the Trilogy, I'd be running it right now, but I think 5W-30 is better for the added stress of the blower.

15-18 at your stated idle speed and with 5W-20 sounds about right.

[Shora]

...thanks for the cigars at the picnic, they were awesome!

J

Any time buddy. I wish that I could have stayed and smoke one with you but my nephew had a party and his mom would have killed me had we missed it. There will be a next time soon.

Best,
Ben

[Shora]

Not everyone runs 5W-30. I switched because in the beginning I wasn't aware of how good Motorcraft 5W-20 really is and I believed the rumour mill that Ford only used it for CAFE reasons. If we hadn't installed the Trilogy, I'd be running it right now, but I think 5W-30 is better for the added stress of the blower.

15-18 at your stated idle speed and with 5W-20 sounds about right.

Thanks! Yeah, I only use MC syn. blend 5-20.

[fastblackmerc]

Just an FYI... Advanced Auto Parts is carrying the Motorcraft 5w-20 blend again.

[Marauderman]

Just an FYI... Advanced Auto Parts is carrying the Motorcraft 5w-20 blend again.
..........and I just picked some up at Wally-World as well.....FYI