gmc_man30 wrote:

> I have a 86 gmc sierra 1500 4.3 3 speed manuel on the cloumn.I just rebuilt
> the engine and when I started it up I noticed the oil pressure dropped.wHAT
> COULD BE THE CAUSE OF THIS? any help would be appreciated ty
>


What do you mean "When I started it up the oil pressure dropped?"


Did it drop as the engine warmed up? That's normal.

Did it drop when you slowed the engine down from a fast idle to a
normal idle after it warmed up? That's normal.

Did it suddenly drop a whole lot while the engine continued at the same
speed? That's not normal.

Are you using a mechanical pressure gauge, or the electric idiot gauge
in the dash?