Hope this helps...my Dodge POS had the same thing going on with it...dropping oil pressure erratically...sometimes good sometimes not... I had already changed out the sending unit so that was not the issue.

I searched the forum alot...seems like another poorly designed American truck issue...I miss my Land Cruiser

Anyways...I went to Autozone and picked up a new oil pan gasket, high volume Melling oil pump and the pickup tube and changed them all out. It took about 3 hours and I did it in my driveway (search the forum for the details...plenty of how-to's out there). There was about a 1/4" of sludge at the bottom and the stupidly designed pick-up tube, while not clogged, only had a slit cut in the bottom to pick up oil through...the new one did not have the cover over the screen which would allow for more oil to be drawn in. I also put a new filter & PVC valve in it too (vibrating like crazy).

I filled it back up with 10/30w and threw in a quart of Slick 50 for high mileage too.

Short story is that the oil pressure is now MUCH higher (at the 75% range on the stock guage) than it was and the engine is much quieter too. I can now put my foot down without having to worry about the drop in pressure as it holds steady. Of course the 10 MPG that I was getting will probably go down to 8....

 

^ what did the pump/pickup tube cost?

 

i put some oil in it two days ago not that it was low but just because the light was coming on to often and it has not dinged since than.. i dont know what its deal is. the truck stil runs real strong and haven't had an issue with it since i bought it

 

Slick 50 is snake oil that is going to be the death of your engine.

 

*noted*



i see that drop in oil psi is common...i have 198K and dont know if the pick-up tube/pump has been replaced. im 3067 miles into this oil change (need to do one) and the oil is stil nice and clear, not black. but i also take that a i dont have a sludge build up.

but what milage have you people experianced the drop in oil psi?

 

could just be a lazy guage, my D150 did the same thing. i put in a aftermarket oil/temp/amp guage and works fine.

 

^ the afermarket works, and the stock one is still funky?

 

I have had this problem twice. first time (for some reason) if I wasn't on the accelerator the truck would idle around 500 rpm's sounds crazy but it did and wouldn't die on me. a seafoam and tb cleaning fixed that. Next time I was lazy and getting my oil changed at one of those jiffy lube type deals and once I went back to doing it myself I didn't have any more problems...I blame the filter they were using.

 

yup, i kept it in for about 2k miles after i put the aftermarket in, i redid the dash and took it out. but yea it was still dropping everytime i hit the brakes

 

I picked up everything for about $100; it breaks down to the pump was $48, the seal was $18, and the pickup was about $23.