Oil pressure.

[a4edwin]

The oil pressure goes all the way up when the truck is on. I bought one from the dealer and changed it and still the same thing. But if I rev the to red line it drops down then goes back up. Any idea why it does that?

 

[HiHoeSilver]

The oil pressure goes all the way up when the truck is on. I bought one from the dealer and changed it and still the same thing. But if I rev the to red line it drops down then goes back up. Any idea why it does that?

Try changing the filter.

 

[a4edwin]

Done that. Unless you mean get a AC Delco filter

 

[HiHoeSilver]

Done that. Unless you mean get a AC Delco filter

No, not necessarily. Just a new one to see if the old was causing the pressure problem. Curious which you did use, though.

 

[SnowDrifter]

You bought a new what?


What does the pressure show key on engine off?

Access to a scan tool? If so, look at oil pressure. If it's showing some absurdly high value, likely sending unit. If it shows normal but gauge is pegged, likely stepper motor