I have a 2004 Dakota with a 3.7 V6. Today out of the blue while idling at a stop sign I heard the ding sound that you hear when your check gauges light comes on. I looked at my gauges and the oil pressure gauge showed no pressure. I tapped the gas and it went back to normal.It stayed normal for a while at some red lights then it done it again. I stopped and checked the oil and it was full. I just changed the oil last week end. If there was a serious problem with the motor why would the pressure drop to zero some times when I stop and not do it every time. Could that mean it could be the factory gauge? Has anybody else had this issue?
Thanks....

May just be bad sender, time to put a manual pressure test gauge on there for an actual reading.

What brand filter did you use?

Fram and 10w30 oil........ It has acted fine the last couple of days.

most likely sludge buildup blocking the pickup screen...don't ask me how I know.

How much is involved or how hard is it to swap to a 5.7 Hemi. Would I have to swap transmissions also?

That and all the computer stuff to go with it including the wiring.