ok so im new to the dodge gas truck world. ive had a cummins for years but finally found a 4x4 play truck that im going to get today. i was test driving it yesterday and the oil pressure gauge went straight to zero i immediatly stopped and turned it off then restarted it and the oil pressure was normal again. there was no delay like it was a pressure drop it just went all the way down. any ideas what it could be? please help

 

Welcome to DF.

Did the engine start making rude noises when the pressure dropped off?

Check the oil level. If it is low, stepping on the gas will deplete the supply in the pan, and, instantly zero pressure.

Also could be just a bad sending unit. If you have a mechanical gauge you can screw in there, you can verify what the pressure is really doing.

 

no thats the wierd part no noises and the oil level is fine. my dad thinks its something wrong inside the motor and also thinks that has something to do with the oil coming up the dip stick

 

Oil coming up the dipstick???? It isn't OVER full is it??

The OP gauges on these trucks have an electrical sending unit. They are somewhat prone to failure....... The BEST way to know FOR SURE though, is screw in the mechanical gauge (even if it is just a test gauge,) and take the truck for a drive.

Oil coming up the dipstick is an entirely separate issue. How many miles on the truck?

 

its not over full but when its at an idle its coming about half way up the dip stick. and it has 186,000 on it and its an 01 5.2

 

Pull the oil cap off, and start the engine. Is there a stiff breeze coming out? If so, find another truck to look at.

 

welll thats another thing i did that and i got nothin. could it be the pcv valve?

 

If there was a LIGHT vacuum at the oil cap, PCV is working as it should be. If it tried to suck you in, then there is another problem. (possibly blown plenum gasket, or, stuck open PCV valve.)

Pull the PCV valve, and give it a shake, should rattle a bit. While it is out, (engine running, oil cap back on) there should be a bit of a breeze coming out. But, not much of one......

The oil climbing the dipstick really makes me nervous though. If you pull the dipstick while the engine is running, and everything else hooked up, do you get oil out of it??

 

no the oil wont come out of it. you can just see when you pull it out that the oil is coming about half way up the dip stick

 

That's just odd......

Check pressure with a mechanical gauge, and see what it says. Take it from there. If you have to have your dad's approval for the purchase though...... might have a bit of a hard time getting the climbing oil thing past him.....

Of course, I would expect the oil to be further up the stick if you pull it with the engine running......