2003 Ranger 3.0 - Oil Pressure Gauge Flickering Issue

[SD-Ranger]

I've spent a lot of time searching for the fix to this and haven't found a solid answer. 2003 Ranger 3.0 with 145,000 miles on it. Idle at low engine temp, the oil pressure gauge is fine, right in the middle. After engine gets to temp and driving, pull to a stop and at idle the pressure gauge flickers back and forth. Once a load is put back on the engine it goes away. I am aware that this is a dummy gauge and when the PSI drops below 8psi it gives a low reading.

Truck runs fine, does not leak any oil, does not burn any oil and no audible knocking from the engine.

What I've done so far -

- New Cam Position Sensor @ 140,000 miles
- Replaced Oil Pressure Sensor
- Using heavier weight oil - 10w-40

What I've seen as possible fixes:

- Checking the electrical grounds on the sensor. (don't think this is the issue but possible)
- Install a oil cooler on the truck, someone on YouTube fixed the problem this way. Said the oil gets thinner as it gets hotter and sends a low pressure signal. Makes sense but expensive and time consuming to install.
- Possible cam bearings worn
-Possible low idle/stall indication sending a false signal

Looking for any help with this or a definitive answer to get this corrected. Some say to just ignore it but I'd like to exhaust all solutions to prevent any major engine damage.

 

[BuckHunter]

Try going to 5w30 oil and see if this helps. Mine was doing the same thing in hot weather with 5w20 went to 5w30 no more problems.

 

[BuckHunter]

Try going to 5w30 oil and see if this helps. Mine was doing the same thing in hot weather with 5w20 went to 5w30 no more problems.

The 10w40 is probably too thick not getting good flow.

 

[pjtoledo]

try a real oil pressure gauge to get the actual numbers.
did you replace just the cam sensor, or the entire cam synchronizer assembly?
nothing wrong with 10-40 oil if it has the correct ratings.
I have used 15-40 diesel oil in several worn engines with good results. only in warm weather of course.
on the 15-40 look for at least SN rating, not all the brands of diesel oil are also rated for gas engines.

 

[Burnsy]

Did you replace the oil SENDING switch\component ? It only has one wire on the elec pigtail connector,located passenger side behind the motor......ive done that to fix it on a ranger 3.0 and also on another 3.0 fixed same problem just by changing the oil.....someone once posted that if the oil viscosity gets terrible aka nasty oil that the sender acts up, sure enough,oil change fixed it once.......ive only ran 5w 30 and 5w20...im in Florida I prefer 5w 30......had 525k miles on one truck original motor sold it guy still has orig motor going near 600k.....my current ranger 287k motor great