Oil pressure
 

Just bought an 06 mega cab with the hemi and am having an oil pressure problem. With a mechanical gauge, what psi should I be seeing at idle once the engine has warmed up?

It used to be, anything over 10 at idle, and then an additional 10 PSI/1000 rpm was considered 'acceptable'. On the newer trucks..... I don't know if that still holds true. What numbers are you seeing?

Seeing 10-11 but it's low enough to set off the check gauge light and drop the oil gauge when I slow to a stop at a stoplight. And I did replace the sender switch already.

If the gauge goes to zero at stop lights, you still have a sending unit problem.

Ran it a little longer this time with the mechanical gauge still on. It goes all the way to 6 psi at idle while in gear. Still a sender unit problem or is that too low?

Nope. That's too low. You have bigger fish to fry than just a sending unit. Need to find out WHY your pressure is so low. Might be new motor time. (or, at least, New-to-you motor.)

Min oil pressure PSI at curb idle is 4 psi. At 3000 rpm you should see 25 to 110 psi.
Are you getting noise from the engine; rods, lifters, something mechanical?
Have you changed your oil and oil filter?

No noise at all and runs great. Changed oil and filter right after I got it. (I've only had it 300-400 miles total)

You get low oil press light at 10 psi?

No. It has to be just under 10