oil pressure gauge erratic. need some help and advice please.

[oncewaslost1982]

Before you blast me please know that I have searched and have read many threads on this forum about this issue. I have a 91 ranger that has the 4 cylinder 5 speed drive line combo. Last night on my way home from work about 9 miles and 20 minutes into my drive my oil pressure gauge started fluctuating. I know that the oil pressure gauge on this particular truck is nothing but a dummy switch. It randomly went dead and came back on. And while driving at throttle It would drop down very low and when I came to a stop it would come back up and flop around. It was only for about a half a mile once I got to my neighborhood. When I pulled in the driveway i shut the truck off and started it back up and the gauge went to normal where is should be. When I started the truck up this morning it took maybe 3 or 4 seconds for the oil pressure to build up to normal. I got almost all the way to work which is a 9 mile drive before the gauge started fluctuating again only this time it wasn't as bad as the first time. And the weirdest thing is that I noticed when I go around a right turn throttle on the gauge pegs over to the left. The truck is running great not overheating and running quiet. I have read that it is very common for the pressure sender to go out in this particular truck. Does this pressure sender sound to be the likely culprit? I have tried to get as much information as possible so that I could get the most accurate potential diagnosis. Thank you so much for any help. Hopefully I can get this diagnosed and fixed pretty quick. Cheers. Have a blessed day.

Justin

 

[Earl43P]

Yes, the pressure sender would be step one.
It's a cheap part and not that bad to replace.

The other thing to look for is that the terminal end needs squeezed to make better contact on the threads.

 

[4.0B2]

or just replace it w/ a real pressure gauge so you really know whats going on...that's what i did on my b2.

 

[oncewaslost1982]

Thanks for the responces. Earl, what is the sender that is at the back of the cylinder head on ds? I thought this was the oil presure switch. ?

 

[oncewaslost1982]

Picked up a sunpro mech oil press gauge yesterday. Going to try and install it the morning to see where my oil pressure actually is. I am going to also try to find a tee so that i can run the mech gauge as well as the factory dummy gauge. Will report back with results as soon as I have them. Thanks for the help thus far guys.

 

[oncewaslost1982]

Well I got the mechanical oil pressure gauge installed. Its only reaching up to maybe 6 or 7 psi..... And if I give it gas it goes back down the line a little. So this would point to? Clogged oil pickup in the pan? What other possibilities are there?

 

[oncewaslost1982]

No odd noises in the motor. But it will not be run again until I figure this out to be safe.

 

[modelageek]

Before you blast me please know that I have searched and have read many threads on this forum about this issue. I have a 91 ranger that has the 4 cylinder 5 speed drive line combo. Last night on my way home from work about 9 miles and 20 minutes into my drive my oil pressure gauge started fluctuating. I know that the oil pressure gauge on this particular truck is nothing but a dummy switch. It randomly went dead and came back on. And while driving at throttle It would drop down very low and when I came to a stop it would come back up and flop around. It was only for about a half a mile once I got to my neighborhood. When I pulled in the driveway i shut the truck off and started it back up and the gauge went to normal where is should be. When I started the truck up this morning it took maybe 3 or 4 seconds for the oil pressure to build up to normal. I got almost all the way to work which is a 9 mile drive before the gauge started fluctuating again only this time it wasn't as bad as the first time. And the weirdest thing is that I noticed when I go around a right turn throttle on the gauge pegs over to the left. The truck is running great not overheating and running quiet. I have read that it is very common for the pressure sender to go out in this particular truck. Does this pressure sender sound to be the likely culprit? I have tried to get as much information as possible so that I could get the most accurate potential diagnosis. Thank you so much for any help. Hopefully I can get this diagnosed and fixed pretty quick. Cheers. Have a blessed day.

Justin

Did you check the Oil?

 

[oncewaslost1982]

Lol. Of course. Its just above the crosshairs on the dipstick and it was just changed saturday.

 

[modelageek]

Lol. Of course. Its just above the crosshairs on the dipstick and it was just changed saturday.

what oil did you use? what brand filter did you use? did youhave the issue before the oil change?

 

[oncewaslost1982]

Had it changed at the local precision tune. Generic filter and i think texaco 10w30. I just got the truck .have only put maybe 150 miles on it. It sat up a lot before i bought it....