thanks. i'll try that. i'll change oil, new filter, and run seafoam until next week. hopefully this will clear it up before the appointment w/ the dodge dealer.

 

Could also be the oil pump pickup tube screen is clogged. That's what happened with mine. Had the same symptoms of oil pressure dropping to zero when coming to a stop after driving. That is until it clogged so much it just dropped while on the expressway. Took the exit and parked in a Wal-Mart parking lot for awhile. Came out and started it and pressure was acting ok so I drove down the road and had the oil changed. After that the pressure wouldn't come back and it started ticking so I shut it off and had it towed to a mechanic. Luckily it didn't hurt the engine.

 

sounds like what is happening to my truck. yesterday i changed the oil, oil filter and put seafoam in. drove it up the highway for awhile. everything seems normal. when i get back to town, the pressure will start to go towards the low mark. if i keep my rpm's at 14 or above the pressure is right at the middle mark. if it's at idle or lower the pressure stays right at the low mark. i'll continue to run the seafoam for a week and see what happens. hopefully it will clean it up.

 

Wow, does this all sound familiar. I have a 2001 Dakota 3.9 automatic. I have 190K on mine. Awhile ago, it started with the check guages and the dropping of the oil pressure. I changed the oil pressure sensor, and also noticed that it was leaking some oil. It leaks where they all do, from back by the distributor, so it really wasn't worth changing. Well, I just keep checking the oil and haven't really had any problems. My husband started driving the truck again a few weeks ago, and let it drop to the point where he had to add 3 quarts (yeah, I know.) and now as soon as the truck warms up the pressure drops and you can smell the oil burning. I changed out the coolant temp sensor, thermostat, and also the belt and tensioner cause it had started to squeal. It seemed to help the problem a little, it was almost like the problem was that it was overheating but not registering on the temp guage. You may want to give that a try. As for my problem, it is still going on, and I am just hoping it isn't the oil pump, as I hear that is not fun to change. (have to drop the axle to access the pan???) Any Ideas???

 

I had a truck in the dealership not too long ago with the same situation. It ended up being a clogged oil screen, which on a 3.9 in a full size 2wd truck isn't too bad. On a Dak, especially a 4WD Dak, its a mother...

 

Thats what I have heard, that in order to even drop the oil pan out to even think about getting at the pump and screen and all that bull, you literally have to drop the whole front axle out of the truck. Not something a back yard mechanic really wants to attempt with winter comin I already ran a Gumout Motor Flush through and put a new filter and oil in it, seemed to help a little for a few days, but didn't last that long, an older mechanic told me a trick for running kerosene through it......I'll let you know how that turns out if I try it.

 

On the 4wd you have to lift the motor some to get clearance to drop the oil pan, but I didn't think you had to do anything like that on the 2wd. Anyway when you're getting low oil pressure readings and the oil level is good, and you know it's not the oil pressure sensor because you either hooked up a manual guage or replaced it then you've got a restriction in oil flow somewhere. Most likely the pickup screen. So by running engine cleaners I suppose it may break down the restriction, but you're also taking a chance at making it worse because if other debris comes loose from inside it can completely clog up wherever the restriction is. After that the best case scenario is you only have to fix whatever is clogged, otherwise you could be looking at serious engine repairs.

 

If a independent gauge reads the same as the truck gauge, you are in line for new main bearings and a high volume oil pump. New cam bearings would be a plus also.
The oiling system runs from the pumo, thru the main and rods bearings and then the cam shaft.
Any excessive clearance in any of these compoonents will result in loss of oil pressure.

 

i took my truck into the shop today. i told them what was happening. they did a few tests on the truck and found that the oil sending unit was not getting enough voltage to the guage causing it to read wrong. they replaced that and checked it again. they said everything was fine now. cost me 160.00 to find this out.

 

hey atleast you know you're not paying off an engine rebuild, be happy about that.