I have a 96 Dodge Ram 5.2L. Upon startup and idle oil pressure gauge & light operate normally. When I travel one to two miles the oil light comes on first and then 10 seconds or so later the oil pressure gauge drops to zero. I stopped the engine.As soon as I startup again both operate normally. When I travel both the light and gauge indicate pressure failure. I replaced the oil pressure sensor switch, the problem remains the same. Before I install another gauge I thought I would searh for anyone that may have experienced this problem. Any ideas or suggestions would be appreciated.

 

do a search for several recent posts with similar problems. a couple of them were solved by a new sending unit, but if you've got the same problem with a new sending unit as the old one, then that eliminates that. could be something simple (clogged up oil filter, low on oil), or could be clogged up oil pickup screen. since it fails a little while after you're driving, it indicates its either something floating around and creating a blockage, or heat/oil thinness related. but, if once you are warmed up, and you get no pressure, and then you stop - if you wait only a minute or two and then start it back up, then oil temp is still hot and oil is still thin, so if you get your oil pressure back, it sounds like some sludge floating around and clogging either the pickup screen or the oil filter.

i'd try an oil and filter change first. let it run and get hot, then pull the plug. check the drain pan for any sludge. change filter too. if that doesn't work, you may have to pull the pan and change the oil pump. like tmsbill said, for the life of me i just can't figure out how an oil pump goes bad. it runs in an oil bath.

 

i have the same problem and have posted on it before and i have tracked down my problem to be my cam bearings...which will be rplaced next month along with an engine rebuild i will post back up to see if it works but i have changed out the pump and screen, sending unit, gauges, and oil filter, thicker oil and once warm it does it....good luck to you and i hope yours is an easy fix

 

I installed a mechanical gauge yesterday. At startup oil pressure nears 50 psi,after drivinga few miles pressure decreases to 25 psi. After twenty miles pressure continued to drop to 10 psi or less. When the low pressure light flickered I stopped. Iparked 5 minutes, thenstarted again with pressure at25 psi. When I resumed driving pressure started to drop asoil warmed again. I'm changing oil, filter and thermostat tomorrow. The truck is running warm which may contribute to the pressure drop. After this my next step is installation of anew oil pump. Thanks to all for each response! I will keep you posted.

 

Replace the oil pressure switch, I have had this problem before with the 5.2/5.9 gas engines and the 5.9 diesel engine too.