ok i have a 99 Ram 1500 2wd 5.2L and i have a couple questions about my oil pressure. i searched the forum looking for my answer and found similiar problems but not mine. My pressure starts off at a steady 60psi then when it warms up it starts to drop then after its warm it idles around 19-20psi and goes up and down between 60 and 20 as the rpm's change. i changed the oil pressure switch and it did the exact same thing then i put on a mechanical oil pressure guage and it does the same thing still. my two questions are what is the normal idle and driving oil pressure for the 5.2L motor. And if my pressure is not normal should i just replace my oil pump? or is there something else i should look at? Thanks for looking.

 

My truck does the same thing. It use to stay at 40 and wouldn't flinch. Now it's higher at idle and goes down as I drive. It's been like that for 3 years.

 

Mine drops at idle and goes up when i step on it. Just like it should.

 

yea mine runs about 35 lbs at idle, a little less if ive been pulling a load, and about 45 at any RPM over 1000

 

but the question is how can the oil pressure go from a steady 40 all the time. then suddenly go to a fluxuating pressure?

 

mine is about 50 cold, then 45ish from then on out......ive heard that a clogged pickup screen can make your symptoms....

 

I have seen mine flux between 30 and sixty PSI.

 

mine starts at 60 when cold then drops a little below 40 and stays there. never moves even if i stomp on it. started doing this when i changed my oil last. i think if it dont hit zero you'll be fine cuz it isn't hurting anything now on my truck.....i hope.

 

I'm having a similar issue. '96 Ram 1500 2WD, 5.2L, 163,000 miles. For years, the oil pressure pretty much never moved off 40 psi--cold, warm, idle, load, didn't matter, it always stayed around 40 +/- 5. For the past year or so, when I start cold, the oil pressure is 40-45. Then when the water temp gets past about 160 F or so, the idle oil pressure will wobble a bit and then drop to halfway between 40 and the bottom of the "safe" zone, so maybe 30 psi? Any throttle will bring it back up to 40.

What I've found is that the longer I drive, the more throttle it takes to get it back up to 40 psi. After 10-15 minutes, if I let off the throttle while cruising at highway speed, even with the truck still turning 1800-2000 rpm, it'll drop to 30-35 psi and run just barely on the low side of 40 at normal throttle for 65-70 mph. I haven't driven it on any long trips since this started happening, so I don't know what it does after more than about 30 minutes of driving.

I just had the oil changed (along with $700 of other repairs) and it's still doing it with nice fresh oil. Oh, and I had the oil pump replaced about five years ago due to a much more drastic version of something like this (as in, the gauge would drop out of the safe zone when letting off the throttle at 70 mph).

 

hey man i have a 1999 5.9L and i had a very similar problem with mine. mine would sometimes even drop below normal idling psi which for my truck is bout 35 and it would fluctuate like your sayin. I went out of town bout two hours from where i live to race my fourwheeler and was driving back and my oil pump went out. Apperantly it was worn out and that had happened at about 86,000 miles. so you may have it looked at just to be on the safe side it cost me about a grand to replace everything in the bottom end and that was labor free dads a mechanic for dodge for 26 years