Question about oil pressure

LowFlying65

Well-Known Member
Joined
Dec 1, 2020
Threads
6
Messages
127
Reaction score
221
Location
92123
First Name
David
Vehicle(s)
FJG Mach1 # M3579
I've noticed my oil pressure is max'ed out the first few minutes after starting. Is that normal?

 

DrZed

Well-Known Member
Joined
Mar 31, 2021
Threads
14
Messages
415
Reaction score
279
Location
Canada
First Name
Cam
Vehicle(s)
2021 Mustang GT PP1 M6
Yup... mine maxes out the gauge almost 100 (or more?) for the first few minutes. Slowly comes down as it warms up. 5w30 Mobile 1.
 


Cobra Jet

Well-Known Member
Joined
Feb 12, 2015
Threads
632
Messages
12,370
Reaction score
15,787
Location
NJ
Vehicle(s)
2018 EB Prem. w/PP and 94 Mustang Cobra
Oil PSI will "peg" based on RPM conditions.

High oil psi upon initial startup is normal in every vehicle. The oil viscosity is thicker due to it sitting and dependent upon exterior seasonal temps (whether in a a garage or not). The colder the engine block, the thicker the oil will be, then as it warms up viscosity changes (thins out).

Oil PSI in ANY engine is always dependent upon operating temps, oil viscosity and RPM.

The oil psi specs below is for a bone stock S550 Coyote 5.0 right from Ford:
29c0870b-b698-4bc5-8cdc-94d6fe7d9483-jpeg-jpg.jpg


That PSI info is also based upon the standard recommended oil for the 5.0 Coyote.


—-
Here was an older thread regarding oil psi:
https://www.mustang6g.com/forums/threads/2018-mustang-gt-15-psi-oil-pressure-normal.109015/


IMO, Ford should have designed the oil psi gauges with a better grid.
 

Atlas1

Well-Known Member
Joined
Aug 11, 2018
Threads
20
Messages
2,896
Reaction score
4,805
Location
Everett, WA
Vehicle(s)
2017 Audi S6, 2021 Mach 1 'M1985'
IMO, Ford should have designed the oil psi gauges with a better grid.
+1
First few times I started my car I was frantically searching the forum for threads on oil psi. It’s a little crazy that cold starts peg the needle on the range of psi.
 

Coastal-Mach

Well-Known Member
Joined
Oct 21, 2021
Threads
12
Messages
1,105
Reaction score
1,688
Location
Wilmington, NC
First Name
Anthony
Vehicle(s)
2016 BMW 528i, 2020 Ram 1500
+1
First few times I started my car I was frantically searching the forum for threads on oil psi. It’s a little crazy that cold starts peg the needle on the range of psi.
Thats why Im swapping out the factory gauges with a mechanical Autometer unit for pressure and temperature.
 

Atlas1

Well-Known Member
Joined
Aug 11, 2018
Threads
20
Messages
2,896
Reaction score
4,805
Location
Everett, WA
Vehicle(s)
2017 Audi S6, 2021 Mach 1 'M1985'
Thats why Im swapping out the factory gauges with a mechanical Autometer unit for pressure and temperature.
there are a few custom gauge manufacturers out there. would be interesting to get something made that matches the style and font of the factory gauge.
 

Coastal-Mach

Well-Known Member
Joined
Oct 21, 2021
Threads
12
Messages
1,105
Reaction score
1,688
Location
Wilmington, NC
First Name
Anthony
Vehicle(s)
2016 BMW 528i, 2020 Ram 1500
there are a few custom gauge manufacturers out there. would be interesting to get something made that matches the style and font of the factory gauge.
I have the autolite gauges from my previous Mach, if they look out of place It will not happen.
 

GreenS550

Well-Known Member
Joined
Nov 18, 2017
Threads
124
Messages
2,305
Reaction score
1,576
Location
Houghton, MI 49931 Oakland, MI 48363
First Name
Bob
Vehicle(s)
2019 Mustang GT Premium 2020 Explorer Limited
Bernouli's equation. Here is a great summary of how it works. Simply, where pressure is greatest, volume is least and vice versa. The reason it is pegged is because volume flow is lower because the oil is cold, even room temp is cold compared to operating temps inside the engine. Cold engine startup is where much of the bearings and rings wear occurs.

Back in Ford's early drag racing days they quickly discovered that oil temperature was a much more accurate precursor to engine damage than pressure.

Note that our newer Mustangs have axle temps and transmission temps, but not engine oil temps. That is the gauge to have if you are really putting the engine through it's paces.

Back in the day my stroked 427 would have only 5-10 psi at idle but massive flow to keep the engine cool. Oil temp is critical to keeping the engine alive.

 

cerbomark

Well-Known Member
Joined
Jun 17, 2021
Threads
24
Messages
890
Reaction score
936
Location
upstate NY/TN
First Name
mark
Vehicle(s)
21 Mach1 700, 6 Spd.#5558
Glad to see this thread. when I drove mine home I noticed oil pressure seemed high to my old school days where 40 or so was max.
 

stev3french

Active Member
Joined
Jun 11, 2021
Threads
2
Messages
38
Reaction score
39
Location
USA
Vehicle(s)
2021 Mach 1 Twister Orange w/HP
I swapped my oil pressure gauge cluster out for a GT350 one which has a higher range for oil pressure. On a cold start it sits right around 105-110psi. I wonder if the oil cooler and other things the car has from the GT350 has something to do with the higher oil pressure, but 100% normal. I too was concerned as my 19 wasn't nearly as high on a cold start. Even still the Mach 1 tends to run higher pressure all around even after warm than my 19 did.
 

Techapma

Well-Known Member
Joined
Feb 9, 2021
Threads
5
Messages
46
Reaction score
61
Location
Texas
First Name
Todd
Vehicle(s)
2021 Mach1, HP, FJG, M6
For those that have swapped their oil pressure gauge for a GT350 gauge, does the backlighting color match the other backlighting in your car?

If the backlighting matched the rest of your car, what part number gauge did you use?

I saw YouTube video of someone that did the swap, and the backlighting only lit white in the GT350 gauge.
 

 
15 - Steeda - 6
Top