For those of you with an oil pressure gauge

[Johnny248]

I installed an electronic oil pressure gauge. I installed a 2" 1/8" pipe to a T. Installed the oe oil pressure switch at the end of it, and the sender for the gauge on the down part of the T. Here is a pic

I am just wondering what other peoples oil pressure readings are like. It has been so long since I've had a real oil pressure gauge on a car to remember what it normally does. It idles around 15-18 or so PSI, and was running about 68-70 while doing 80 on the highway. It moves around quite a bit. Just wanted to see if this was the best way to install it off that port near the oil filter, and what everyone elses gauge does.

Video

 

[sdan27]

I put an electric gauge on my Powerstroke a few years back. It shows about 50 psi at idle when it's cold and abot 15 psi when it's hot. Runs about 50 psi at 2300 rpm hot. When it's real cold in the winter I sometimes can push it up to 75 psi or so. All that is going to vary depending on your engine application though.

 

[Johnny248]

Does it move around quite a bit while driving? My truck has a factory gauge, it it seems to sit around 30 or so at idle , and then like 50 while driving. I'm sure they are somewhat different setups, but it just seems that maybe the oil pressure should climb to its high point and stay there once you get the engine spinning above idle?

 

[Johnny248]

Here are the specs from my service manual.. Pretty broad range of numbers here. What is up with that??


4.2 or more at idle, 43-100 at 3500rpm lol or more? =)

 

[mechtech2]

Temperature will make a huge difference.

 

[Johnny248]

I have not used this car enough to really check out the temp difference, but I have noticed that on other vehicles. especially at idle.

 

[KLowD9x]

When I had my Volvo 244 Turbo, it came from the factory with a 3 bar oil pressure gauge.

One thing that really interested me was the fact that, with dino oil in the sump and after only 1000 or so miles, the pressure would drop to about 1 bar at hot idle. The longer it was in there, the lower the pressure would be when hot. That was Rotella T 15w40.

But, with Rotella T Synthetic 5w40 in the sump, I could take it past 3000 miles per change without it ever dropping below 2.5 bar, even at hot idle.

That is what sold me on synthetics.

 

[Johnny248]

I also had an a 87 Saab 900 8v n/a. I installed one of those inexpensive 3 gauge auto gauge deals, and I would notice also that when I would put fresh oil in it, the oil pressure would be much higher until I started to put some miles on it. I started using Maxlife in it and it seems like it it did a little better when hot. What kinda of impact does oil weight have on oil pressure? If you ran a 20w50 oil, would you have higher oil pressure? in theory?

 

[Trav]

Lower at idle to high highway numbers are normal.
Temp,viscosity all play a part in even the steadiness of the needle.
With a 0w-30 my Expeditions aftermarket gauge swings a good bit with rpm,with 10w-30 its more stable.This is meaningless as long as the pressure increases and remains stable.

This behaviour is exactly the reason Ford went with to idiot gauge.The dealers were flooded with low oil pressure at idle complaints,there was no fix it was the nature of the beast.

 

[sdan27]

My oil gauge reads pretty constant so long as my engine speed is constant. I've noticed that as well, immediately following an oil change my oil pressure reads a little higher until I get a few miles on it.

 

[river_rat]

PSI = 60 at cold idle and 10 hot idle. 40-45 at hot highway.

I like to see at least 10-15 PSI/1000 rpm

 

[Gary Allan]

What's it read at cold start? Some OEM gauges are damped by the PCM. My wife's gauge read like yours, but the engine can't nearly rev that freely (nor reach that high an rpm) and attenuates @ 54psi.

 

[OVERKILL]

1987 302HO, stock pump and bottom-end, 330,000Km.

10w30 or 5w30: 65psi cold start (pump bypass pressure)
38psi hot at idle
~45psi or so hot cruise.

 

[Gary Allan]

Oh, I didn't get with the program

99 4.0 HV pump

54 cold start
54 off idle with anything over a 20 weight (when used, will produce about 24psi at hot idle)
54 just about all the time.

Stock pump
12-14 hot idle
42 cold start
24 highway (about 2500rpm)

2002 Jeep (same as stock pump on 4.0 - but 2/3 the engine)

42 cold start
38 hot idle. That's on 0w-10.

 

[Junior]

98 f150, 5.4 162,000 miles 65-70psi at 2000rpm 25-30 psi at idle
04 accord 3.0V6 122,000 miles 65-70 psi at 3000rpm 12-14 at idle

All pressures at full operating temp. Both seem to have a relief setting of around 80psi. Idle is about 700rpm. Both vehicles pressure readings match the specification.

 

[Johnny248]

When I start may car cold, and the engine idles a little higher, it will sit about about 80 psi, and if I drive it right away, it goes way over a 100

 

[Gary Allan]

Originally Posted By: Jdblya
When I start may car cold, and the engine idles a little higher, it will sit about about 80 psi, and if I drive it right away, it goes way over a 100


You're exceeding the relief ports ability to shunt flow. Not a bad thing. What Amsoil product are you running?

 

[Johnny248]

I am running the SSO. I the oil has 4790 miles on it. I did an uoa on it at 3757. I swapped out the Eao filter and installed on of my OEM filters I had on the shelf and topped it off. My insoluble were high, but I'm pretty sure it was from when I sampled it because everything looks great. I use this car in the nicer months, and it will prob get stored sometime in November I am thinking, or when we get snow. At that time, I will change the oil before storing it again and send in another sample.

 

[440Magnum]

I have mechanical OP gauges on my old Mopars, electric on my Jeep. All behave very much like yours does, but you have to consider the oil temperature, engine temperature, and oil grade when making any comparisons. I have one '69 440 with ~160,000 miles that runs about 68 PSI hot at highway speed, about 20 PSI at idle on RTS 5w40. My 18,000 mile (recent rebuild) 440 ran >85 PSI hot at highway speed, 30 psi at idle on RTS 5w40. Switching it to a 5w30 instead netted me a much happier 18 psi at idle and 75 PSI at highway speed.

Cold oil pressures are *much* higher- I don't normally use cold oil pressures for making any kind of judgement about the condition of an engine or the suitability of an oil (except maybe cold/idle being sky high tells me go to a 5w30 from a 10, or a 0w30 from a 5). I've seen high-mileage engines that had seemingly normal or even high pressures when cold, but when hot the pressure will fall off alarmingly. My old 460,000 mile 318 still manages about 10 psi hot idle, but shows 35-40 psi cold idle. Cold at cruising speed is a normal-looking 60+ psi, but hot at highway speed speed is about 45-50 psi on that one- 10w30 oil. Not quite time to shut 'er down for a rebuild yet, but getting real close.

 

[VNTS]

Some of the newer pumps are low pressure high volume.

My 2.5 Turbo in my shadow with a Autometer electric guage shows about 65 PSI cold, 15 PSI hot idle and about 30 PSI hot at highway speed at 2500 RPM.


Idiot light switch comes on a 4psi hot. According to FSM min pressure at hot idle should be 6PSI