It started doing this right after I changed my oil. I just replaced the pressure sending unit. I am running 5w30 synthetic blend. This is the first time that I put blend in it. Also now there is oil leaking out right at the drain plug. My dad says that there is some kind of gasket that is suppose to be there. Now when I start the car it runs about 40 to 50 psi. After it warms up the pressure is about 30psi while driving and it drops to 10psi at idle. If I brake too hard it drops to 0psi and the bounces back up if I let off the brake. The engine make no sounds when this happens and the rpm is unaffected by this. What is wrong?

Your dad is correct about the drain plug requiring a gasket. Can get them on the Help rack dirt cheap. Will be a 1/2" ID.

As far as the 0 psi when on the brakes there is a possibility the pickup fell off the pump. While putting a gasket on the drain plug and hte pan is empty, try two things: tap on the bottom of the oil pan with the palm of your hand. Does it sound like something is bouncing around?

Can also use a piece of wire (coat hanger) and insert it through the drain plug hole. Sweep it around the bottom of the pan searching for a loose pickup.

RBob.

my car does the same thing sometimes. if it is in fact a loose pickup, will it harm the engine if it doesnt get fixed? mine's been doing it for a while now but next oil change i will check to see if anything is loose inside.

My Camaro doesn't do it but i noticed just the other day my Jimmy started doing it. I thought it was caused by needing a oil change, but i guess i'm wrong. If any of you figure anything out, id appreciate the information!

Two possible causes: 1) Really low oil level, and 2) the aforementioned pickup falling off the oil pump.

For me, it was #2.

so is it bad if its not corrected???

You're starving the bearings of oil everytime the pressure drops. Generally, that isn't a good thing.