oil pressure went to 0 on the cummins

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5,988
Location
Houston, Texas
Thread starter
My dummy gauge on my 6.7 went to zero when driving. The truck has a 6psi oil pressure switch, and doesn't show anywhere near what the actual reading is if a real mechanical gauge was used. Typically with a real gauge the pressure is 20psi hot idle and 75psi plus on a cold start. What do you guys think happened? I restarted the truck and it went back to normal and has been working for a couple weeks now. There was no oil on the ground or any weird noises, so I don't think it actually lost pressure as I wouldn't have made it home. I would have thought the check gauges light would have come on also, but it didn't.
 
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1,526
Location
TX, USA
I am not sure if the truck engine have an Oil Pressure Sender/Sensor that send the signal to the gauge. That part is bad.
 
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544
Location
Roswell GA
My old Ranger also has the dummy 6-psi gauge. The sending unit was bad also and like yours, no leaks, etc. But it scares the heck out of you when it suddenly reads that low. Replace it with an OEM unit. The aftermarket one I got at first also went bad. And considering it's a PITA to get to, I really don't want to do it again. HTH
 
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10,425
Location
Cincinnati, OH, USA
It's the stupid on/off OPS switch, the computer "guesses" what your oil pressure should be when it's closed, goses crazy when it doesn't. My ‘06 needed one a couple years ago.
 
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2,183
Location
Flaherty, KY
I had a Mazda Tribute with the Duratec 3.0L V6 whose oil pressure switch started flaking out. Oil light started flickering and oddly it did it mostly at idle which is pretty normal behavior for a vehicle with actual low oil pressure. I pulled over right away and upon checking the oil level, it was full. Pulling the oil filler cap off with the engine running revealed a healthy amount of oil splashing around. It had enough miles on it to make me question worn bearings, but the light blinking and coming on solid was so erratic I concluded it must be something with the switch. I was right, the switch was actually leaking oil and needed replaced.
 
Messages
4,625
Location
Fort Worth, Texas
Chrysler products are notorious for oil pressure switch failures. Change it soon.....I've seen a Cummins/Bosch engine controller get filled with oil from a bad/leaky switch, The oil will wick through the insulation!
 
Messages
781
Location
Texas, USA
This happened to me with a fully-loaded Budget moving truck. Got about 100 miles outside Atlanta (moving to Phoenix) and noticed the oil pressure gauge had crept its way down to about 10psi on the highway. Dropped to about 1psi when I let off the gas to exit. Stopped at a weigh station to call Budget. They said since the engine hasn't slung pistons all over the highway, drive to the next town and stop at X gas station to meet our technician. When I started the engine to go meet the tech, the gauge read normal. Tech did a voltage test on the pressure sender and concluded it was bad. Drove the rest of the way to Phoenix reading 0 oil pressure (except in the morning and after any re-starts) It's a unnerving sight.
 
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Messages
1,425
Location
Perris, CA
Originally Posted by WylieCoyote
It's a unnerving sight.
The one on my XTerra pegs itself to the end of the gauge as soon as I turn the key on, engine running or not. I'll get around to fixing it eventually.
 
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