Can anybody tell me what the normal oil pressure should be? My 5.2 liter engine shows 60 to 70 psi when i first start up but drops to less than 40 and stays there. Now I realize the oil is thicker when cold but I am not sure if the sending unit is bad or the oil pump is not putting out after warm up. I get no tapping or clacking of the engine suggesting oil starvation. I did change out the plenum on the intake manifold and was wondering if the excessive oil consumption that I experinced prior to the changeout could have clogged the oil sending unit??

 

40 when warm is perfectly normal. You're ahead of the game with the plenum fixed.

 

The sending units are not know for their reliability, or longevity. That said, according to chrysler, anything over 10 psi at idle (fully warmed) is "OK", after that, about 10 PSI per 1000 RPM.

My 187K mile 5.9 with a two year old high volume pump manages about 35 PSI at warm idle, and maybe 45-50 at cruising speed. Sending unit was replaced in the last year. I don't think the gauge is real accurate either. Wanna know whats REALLY happening? Install a mechanical gauge.

 

mine runs a little under 40 at idle and eeks up to about 40 at speed.
i agree its not very accurate. my sending unit went bad about a year ago and i replaced it. for about 2 weeks the gauge showed very high oil pressure, and then it self adjusted itself back down to the middle of the gauge. i'm sure the real pressure hasn't changed any up or down during this period.

 

Mine does the exact same thing. Nothing to worry about....good job getting that plenum addressed.

 

Thanks all for the info. Greatly appreciated

 

Im having a similar issue with my 95 5.9 v8 but seems to be backwards to most of the other oil pressure issues on here. My pressure sits at about 40 at idle but when I accelerate it drops to zero. It's only been doing this for a couple days. Soon as I noticed I checked oil and it was about a quort low, not significant since it was about a month since I changed oil. Somebody s suggested maybe clogged filter so I drained my oil and put on a new filter, when I did this my oil smelled a little burnt. Not sure what this means but since I'm not seeing any similar issues I'm getting pretty spooked about it. My next guess is oil pump but that's me guessing.. any help or ideas?

 

Put a mechanical gauge on it, and see what oil pressure is really doing. If it is indeed dropping to zero, pull the pan, clean out the pickup, and replace the oil pump. See if that makes any difference.

 

That happened in my Durango with the 5.9L, it was the plenum burning the oil and fast. Got so bad I couldn't add it quick enough. Would loose 3 quarts in 10 miles. Started smoking and then BAM rod knock.

 

I had a similar issue on my '97 8.0L that turned out just to be a faulty sender. Of course, I spent a day dropping the pan and checking for a blocked pick-up tube for nothing, but at least I know the pan & pick-up was clean. I'd change the sender before getting too deep into anything else and definitely check the plenum gasket.