Oil pressure gauge's act very different!!!

Messages
3,542
Location
Colorado
I own a 2003 Chevy Silverado with a 5.3 liter engine and my oil pressure gauge moves a lot durring driving. It is a 40 psi at idle 50-60 crusing at 60mph and when I floor it it goes up to 75-80psi. My friends 2002 Ford F150 with the 4.6 liter engine does not move at all! The gauge does not have any numbers, just a high and low and his sits right in the middle all the time. Why dosen't the Ford move? Why is this and is this normal? My 2002 Camaro also fluctuates a lot also. Is it good to have fluctuation through out the rpm range?
 

Patman

Staff member
Messages
21,988
Location
Oakville, Ontario
The reason for this is because GM uses a real gauge that shows actual instant pressure, while the Ford uses a gauge which is more of an idiot light really, it doesn't react to up and down pressures, but just basically stays in one spot unless the pressure is super low. All Fords have been like this for years (my 87 Mustangs were like this and so is my mom's 94 Probe GT)
 
Messages
345
Location
Northern California
It is not a real gauge it is a needle hooked up to where the light should be. I think it is 6 psi that activates it. I wonder also about other gauges in Fords they seem to be dampen to stay in the middle range.
 

9c1

Messages
323
Location
Berwyn, IL
Ford is not the only vehicle to do that - one level on the gauge. Some GMs do the same thing. Specifically 1994-69 Impala/Caprice (except police cars) do the same. Most GM gauges are far from accurate, so even if there are numbers on the gauge face, take them with a grain of salt.
 
Messages
4,799
Location
Lakeville, MN
Ford oil pressure gauges are nothing more than a glorified idiot light - so long as its between about 8 and 90psi, the gauge will stay dead in the middle. Reality is those who have hooked up real oil pressure gauges note the same fluctations as you see on the GM products - idle somewhere around 35psi and above idle around 70 psi or so.
 
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