Since I converted my oil pressure sender to a real one, I wanted to know what the gauge calibration is. There are no numbers on the factory gauge. So, I temporarily hooked up a mechanical one and went for a drive. This is a 5.0 with over 120,000, 15W-40 oil and Motorcraft filter.

Max oil pressure seen: 60psi. It seems to be regulated to that.
Cold idle: 50psi
Cold cruise: 55psi
Warm idle: 40psi
Warm cruise: 50psi
Warm full throttle: 60psi

That explains why the stock gauge does not move as much as I thought it should. 40-60 is the total operating range.

It looks like I could run much thinner oil, if it weren't for the leaks.

Jim

 

I converted my 1999 3.0L Ranger over to an analog sending
unit also, and I don't see much variation in pressure either.
I'm running Castrol 5W30, with a Motorcraft filter.

 

I have an analog gauge on my 2000 ranger and it moves a great deal from 25 on up to around 70psi. Of course this depends on what speed rpm I am pushing. I think the max on my gauge is 80, I don't think I got the 100 psi max gauge.

 

Most in not all oil pumps have a relief that is set between 60psi and 70psi. My 460 has about 30 psi hot idle with 205,000 miles I never see over 75psi

 

I just checked mine and it is a 100 psi gauge

 

Jim, would you translate those pressure readings by which letter they correspond with in \ N-O-R-M-A-L / ?

 

I also think it could be relevant to include reference to the type and weight of oil used AND the oil filter used.
Some oil filters are better known for their quality construction than others and it seems prudent to consider that leaking relif valves on cheap filters could be contributing to oscillating oil pressure indications.
Please continue to include reference to engine mileage.
Congrats for those that have high mileage and good oil pressure. That would seem to me to be an indication of well cared for engines that one could expect to have a long and healthy life.
My personal goal is to get several hundred thousand carefree miles out of my trucks/cars. It would be nice to chose to replace my vehicles because I want a change rather than having to as a result of engine/drivetrain failure.
And it appears that use of quaklity oils and FILTERs has an effect on longevity.

-Cajun

 

Jim, awhile back you asked what readings I was getting. I finally hooked up an electric gauge to my 5.0 and was surprised to see that I have 75psi on startup and while cruising. After the engine is as hot as it can get, I show about 50-60psi at idle. Should I trust these readings to be pretty accurate? I'm starting to hear that mechanical gauges are the more accurate choice. Thanks!
-Mike

 

Cajun, I believe the relief valve that regulates oil pressure is in the oil pump, not the filter. The filter does have an anti drainback valve that can affect how quickly pressure comes up after starting the engine, but it does not affect operating oil pressure.

 

My oil guage sits between the R - M and climbs up just past the M on the highway. Is this "Normal" for a 4.9 with 130K miles?

 

The gauge you have in your truck isnt a real gauge. If it moves a bit that is just voltage fluctuations. They will read the same anything above 6psi. If it is less than 6psi the gauge wont read at all

 

Well..thats pointless..... Time for a real guage...