I have a '99 Ranger 4.0. The oil pressure used to shoot up almost too fast when started up. Now it doesn't register till a couple of miles down the road and then shoots up to normal. It doesn't knock or anything and seems to run fine. Wondering if the sending unit or gauge is at fault? When it was working it seemed to shoot up really really fast and not build gradually. Maybe that is good but it looked strange.

 

the oil pressure sensor in rangers isn't "real". it only reads extreme low, extreme high, or normal. no in between. if it is REALLY acting weird replace the sensor. it is called "oil pressure switch" at autozone. I paid 3.99 for mine. i though mine was broken so i replaced it but it was just not real to begin with.

 

Is that the same thing as the sending unit? If not where would it be located. Thanks for your reply.

 

replaced mine twice now. hasnt fix the problem yet. just letting you know

 

yes its the sending unit. it is near the oil filter on most car. wiring coming out. screwed into the block.

you can't "fix the problem" because there is no problem. its how the computer read the information. if you want an accurate reading on your full pressure get a scanguage or setup a separate gauge for it.

 

Got it done. Seems to have fixed the problem. BTW the sending unit on a 4.0 is located at the front on the drivers side. A real pain to access. Took wheel, and fender flap off to get to it. Thanks for the help.