hello! I've noticed in the past few months of driving my 2000 ford ranger, that my oil pressure gauge immediately spikes to the middle (when I start it) and doesn't move at all, no matter how high of rpm it is, it never rises or goes down. i know its a stupid question. but is the gauge supposed to do this? is it just a useless gauge that tells you that you have some oil pressure?

 

Yes, it is basically like an oil pressure lite. It will only drop when the pressure is below around 3 to 5 psi.

 

By 3 to 5 psi, your engine is already facing damage, so it's a worthless gauge.

 

are there differences between years. My 2008 has an oil gauge that apparently is directly, hydraulically, connected to the oil galleries as it continues to read pressure even after the engine is shut down and will take over half an hour to drop to zero. (good bearings???)

 

Nope, Ford used this style of gauge since the 80's and never changed it.

The sending unit is attached to the oil galleries, but it's an electronic signal that goes to the computer. The gauge is likely just staying at the last position.