Dakota oil pressure woas

[440Magnum]

Whenever a Dodge LA-series engine (3.9, 5.2, 5.9) shows flaky oil pressure, suspect the gauge sending unit FIRST. They tend to get flaky much more often than the engine actually develops an oil pressure problem. Yes, you did have a real problem before, but it could still be the sending unit this time. Its a cheap/easy thing to check rather than dropping the pan or pulling the intake.

Second- if you had a ton of grit plugging the pickup screen in the past, its probably because you have a leaking lower plenum gasket on the bottom of the intake manifold. If you didn't fix THAT, then the grit will come back over and over.

 

[mechtech2]

This also could be a bad oil pressure sending unit, or gauge.

 

[The_Eric]

Originally Posted By: DanielinTheLions
I was thinking that 10 months wasn't too excessive. I was also considering of sending in a sample of this oil change to see if it would reveal something, if I do that though I think I probably shouldn't add MMO before draining. I changed the PCV about 10,000 miles back. As for the thermostat the truck does tend to be a bit slow on warming up, the previous owner told me he changed the thermostat several times because of that with no change but from talking with others I don't think it's as bad as he thought. Usually reaches full temp on the gage by the time I'm half way through my commute. I have been considering taking the long route home once a week...I guess maybe I should just start doing that.


About the thermostat- Go to the dealer and buy an OEM stat.. I've seen too many aftermarket stats not work as they should.

 

[DanielinTheLions]

Well I decided I should install a mechanical oil pressure gauge to get a better picture of what is going on. It turns out that the dash gauge is serverly inaccurate when the engine is hot. At engine start when hot pressure comes up instantly on the mechanical gauge but can take as much as 40 seconds to show up on the dash gauge. Also the mechanical gauge can be showing 60+ psi while the one in the dash shows barely inside the safe range. With the engine cold the difference is not as drastic but at times the gauge in the dash shows a rather low reading while the mechanical one shows great pressure. This is the second sending unit on the truck so I'm thinking there's no point trying to replace that, the mechanical gauge was much cheaper and far more reliable than either sending unit.