How long after starting the truck should it take before the oil pressure is up to normal? After starting, it's a good 1.5 to 2 seconds before that needle pops up into the normal range. In my Jeeps, it's always up much faster than that (they're gassers, though). I don't know if this is just a lag in the gauge, or if this is normal for a diesel, or if there's a problem. Hope I'm overreacting . Any advice would be appreciated!
Chris

 

That's normal.

 

The Cummins block is a lot different that your gasser engines. It has several oil cooling jet for the pistons. So it does take a bit of time to blow the air out and push the cold thick oil up.

As in my owner manual is says "...to increase the RPM it approx 1,000 and return to idle."

I admit it helps bring the oil pressure up. But it is totally normal for the slow to rise oil pressure gauge.

 

Great! Thanks, guys .
Chris

 

The oil filter also drains through a siphon action, down about an inch or so. My commercial engine and filter drain even more, about 1/2 empty. As a matter of fact I have a little trouble checking oil as a ten minute shutdown is near two quarts different than an overnight sitting. Part of that I think is the air compressor holding oil until it is drained good.