1998 Ram 1500 5.9L 2wd. Dash oil pressure gauge readings crash from 50 to 0 and sometimes rebounds imediately, causing dash waring lights and chimes. I have replaced oil pump and pickup, new pan gasket, oil, filter and oil pressure sending unit with parts bought from NAPA. Acording the the dash oil gauge and warning displays, the problem continues. Just can't figure it out. Any posative suggestions welcome.

 

Check your oil pressure with an actual gauge.

Does it do it while idling? Anytime? Warm or cold?

 

I have not tried threading a supplemental gauge yet, I guess I could tread into the sending unit location. The condition seems randomly occuring. Seem unusual but may happen most frequently when rpms are low and turning the steering wheel. Like parking the vehicle. I do not drive the truck except to test a hopeful remedy. I did clean a good amount of debris and gunk from the old pickup. Now oil is golden on the stick and the correct volume in the engine. I think it's an electrical issue?

 

Since you have replaced just about everything else in the system...... and you don't mention your engine making rude 'low oil pressure' noises..... Check the electrical is a logical next step. Could just be a loose, or dirty connection somewhere, or a bad ground. You can download a service manual for your truck from this thread. Wiring diagrams are in section 8W. have a look, it'll give you a good idea of what to look at.

 

HeyYou thanks. I will download that link in a few minutes as it is getting to cold out for me. I did locate a frayed ground running from the passenger side head to the firewall. Doubt this is the cause,but it needs fixing

 

Single digit temps here today. I am NOT going outside, if I can possibly avoid it.

 

UPDATE. I fixed one ground wire to the left head and one sketchy wire, which were the only loose or bad wires I could find around the engine. Took the truck for a 15 to 20 minute drive. All seemed reasonable though the oil pressure gauge reported low pressure alititle under 40. Then at a stop sign, warm engine low rpms the oil pressure gauged crashed to 0, warning chimes sounded and dash lights flashed check gauges. Back to the house gauge crash numerous times. Turning the wheel apparently has nothing to do with it as I previously speculated. New to the situation now though, when it crashes I have to rev up the rpms for the for the gauge to show pressure. Going to by an external gauge to fit sensor location next. For now it's back to the barn. Totally frustrated.

 

Sounds like another bad sending unit.

If you can just barely touch the gas, and the pressure shoots back up, the sending unit is highly likely the culprit.

 

I had the same thought. Im wondering if the freyed ground might have messed with it too. The ground wire is very closed to the sending unit.

 

Back in the day, the various auto manufacturers could come up with oil pressure sensors that would outlast the motor...... along about the late 80's, early 90's, that changed.... and it seemed that you need to change the oil pressure sensor, along with the oil change...... one tiny little air pocket, that was impossible to avoid, and the sensor was toast...... Seems the aftermarket sensor quality isn't any better. (if not worse.....)