[nate_378]

Ok, so i have a 1995 Dodge half ton 4 wheel drive. When i crank ot cold, the oil pressure shows 40 psi. As it warms up the pressure will drop to between 17 and 20 psi. And the light will flash intermittently. Now, there are no sounds coming from the engine that would indicate the pressure is actually low. But, checking with a mechanical oressure tester shows the pressure to match the gauge reading. I had replaced the sending unit, and no help, ive replaced the oil pump and no change. At this rate im at a loss. The truck runs great, has plenty of power, so i wouldnt think it needs a rebuild. But im at a loss. The truck has 318 magnum in it and im running delo 15w40 with a Wix filter.

 

[djh3]

Well I would say the by pass spring. But if you have replaced the pump, generally the spring is part of that assembly.

 

[T-HAWK$LTD]

I would try running straight 40 weight oil in it.
That 15 number is what it is warmed up.
And I suspect your readings reflect that.

 

[Moparite]

What does it go up to during rpms/driving?

 

[nate_378]

What does it go up to during rpms/driving?

At a warm idle in park it idles around 600 rpm. At a stop light with foot on break, it idles around 400 rpm.

 

[14vern]

You can lead a horse to water but you can’t mak.......

 

[Moparite]

No, What does the psi go up to while driving(rpms off idle)?

 

[nate_378]

Running 60, it sits around 1500 rpms and pressure reads 20psi. At 70, it sits around 1800 rpms and around 25psi.

If you go give it gas to pass the pressure will go up

 

[Moparite]

20 is to low, Mine will stay at around 40 most of the time. How many miles on it?

 

[nate_378]

20 is to low, Mine will stay at around 40 most of the time. How many miles on it?

159,000

 

[Moparite]

And the light will flash intermittently.

Since the gauge is saying it's low and the light is flickering it would make sense. I would think you have worn bearings, The oil goes threw them without actually building pressure. Or your oil passage to the sender is partially clogged. When you replaced the pump did you inspect the pickup screen for any blockage?

 

[nate_378]

Since the gauge is saying it's low and the light is flickering it would make sense. I would think you have worn bearings, The oil goes threw them without actually building pressure. Or your oil passage to the sender is partially clogged. When you replaced the pump did you inspect the pickup screen for any blockage?

Cleaned the pickup tube and screen, there are no obstructions in there that I saw

 

[Moparite]

Still sounds like worn bearings, Try using thicker oil and see if the pressure goes up. If it does you know the problem.

 

[nate_378]

Still sounds like worn bearings, Try using thicker oil and see if the pressure goes up. If it does you know the problem.

Bumped it up from 10w30 to 15w40 and itndidnt change a whole lot. Could try 20w50 or a straight 40 weight