Thanks ahead of time for the help ya'll. I've gotta 97 dakota 5.2 automatic with 184k miles. it's been pretty well maintained. I changed the oil right after i bought it and noticed the oil psi was dropping at idle once warmed up. It holds a good 60psi while driving. I did a lil research on here checked the oil level...it was low. I added oil and monitored it, sure enough the plentum gasket was shot. once i dove into it I found it had been replaced before and had started leaking again. I'm a aircraft mech by trade, so I made my own plentum plate. I installed it last night, worked as is should...no leaks. I made sure the oil was all serviced up. Here's the deal...the oil psi is still dropping. I'm not sure how many miles is on this motor, but it's still real strong. It dosen't burn oil. Other than the occasional lifter tap at start up, there's no sign of wear on the ol motor. So what ya'll think.

 

Are you using the suggested viscosity motor oil for your engine? You might try a slightly heavier oil (like 15w40 or 20w50.) If that doesn't take care of it, you might try a new oil pump, and if that doesn't do it, an engine overhaul is in your future (or a crate long block.)

The last time I had a low oil pressure engine, changing out the cam & bearings? did the trick. Years ago and on a Chevy small block. Before that, I had a Toyota OHC 6 with low (really low) oil pressure--it was worn out & eventually got a rebuild. (turned the crank, oversized bearings, rings, etc.) That ohc engine was pretty much a nightmare, tho a good learning experience.

 

I will move this to the 2nd generation Dakota sub-forum.

 

What is the oil pressure? Put a mechanical gauge on it and test. The electric gauges (oem) are not that accurate. It is normal for the pressure to drop when the engine is warm.

At curb idle, 6 psi is the min specification.

 

Old rule of thumb is 10 psi per 1000 rpms. If you are down in the lower ranges of the less than accurate stock gauge during warm idle, you probably still have 10-15 lbs of pressure, which is perfectly fine for a higher mileage motor. Its the pressure at engine speed that's most critical, which from what you say, sounds just fine. As long as there is no deep sounding knocks coming from the lower half of the motor, you're likely ok. I recommend switching to a quality filter, such as a Wix or K&N and using some Delo 15w40 oil.

If one was to get extreme at this juncture, pulling the oil pan and checking the oil pump pickup is the first place to start if pressure is worse than I describe.

-Justin

 

well, it's pushing 100 degrees today. the oil psi dropped to 0 psi and the light comes on everytime i went to idle. If you raise the idle by 50-100 rpm it jumps to around 40 psi. While driving the pressure is at least 60 to 70 psi It dosen't drop as much in the morning with cooler temps. I'm running 10w30 I believe that's what the parts house said it calls for. It's Royal Purple oil and Royal Purple filter. I'll try checking it with a mech gauge these weekend. I'm thinking the thicker oil might help. Thanks ya'll

 

Step up to a higher viscosity oil as mentioned, especially with heat consistent like you've stated. May also check the integrity of the oil pressure sending unit itself.

If zero readings are confirmed with a mechanical gauge, it might be time to pull the pan and check the pickup screen for debris and throw in a new oil pump at the same time.

 

Everything sounds good to me just a bad sending unit very common.