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I own a couple of rangers. The one in question is a 1992 3.0 V6 Automatic.
Only after long drives on the highway my oil gauge starts bouncing while idling in drive. If I tap the gas the needle goes back to the middle, but once it idles again it again bounces.
It bounces between the middle and low, never all over the place, just between low and normal.
When I turn the heater on it causes it to bounce harder, it gets lower to the L when I turn the fan on higher and higher. The load seems to effect it as well.
Any ideas on this? Some people say its the oil pressure sending unit or regulator, but a lot say it didn't fix their problem. Some say it could be the alternator, which might make sense since it does it even more under load. But my battery has never died in the year its been doing this. However my battery is 9 years old... it still has 300 CCA and the battery guy said its still good to use and I don't need a new one.
After about 1988 all Fords had an oil pressure switch on the engine, below 5psi = off, above 5psi = on
Gauge is either off or on, any movement of needle would be an electrical issue
BUT........if oil switch wire connector is loose or switch is failing then you would get a jumping needle.
On the 3.0l the oil pressure switch is on the passenger side, behind the head, on the block, next to bell housing.
It is a SENDER so only 1 wire, this means the threads of the switch must make good contact to the block for a good Ground, completing the circuit.
So if you replace the switch leave bottom threads bare, and use sealant, if you want, on upper threads
So if it’s an electrical issue do you think it could be my alternator or battery? Like I said, my battery is super old...
i might try try replacing that part you mentioned if it’s not too hard. Is it in an easy place to get to?
it only does it after a long drive on the highway when I’m pushing it hard. Does that mean anything as well? It never does it on shorter rides or rides where I’m not WOT and pushing it hard.
Also a major question I need answered Ron... is this something urgent? I see people with the same problem saying they just ignored it for years and nothing happened. If that part fails completely could it ruin my truck? Or will it just not read oil pressure correctly... I’m thinking it just tells me the oil pressure and doesn’t have any impact on the actual pressure. Sounds like I just won’t know if my oil pressure it good or not, which I can live with for a while.
im really thinking it’s electrical since when I turn the fan on when it’s acting funny it’ll cause the needle to drop lower as it bounces around. Not sure if it’s the alternator or battery... I should get a new battery since mines so damn old and it only has 300 CCA last time I tested it about 10 months ago
If headlights are not dimming at idle then alternator is OK, and the alternator supplies ALL vehicle power when engine is running, battery is "off-line".
Battery has 12.8volts maximum, alternator puts out 13.5volt minimum, so when alternator is working battery receives voltage, charges up, no voltage leaves the battery at that time.
Battery is strictly used for starting the alternator/engine
Batteries do wear out, 5 to 7 years is average, the chemicals and plates inside wear out.
Ok I’ve tested the battery and alternator with my volt meter like you’ve taught me before. It tested out fine back then. I’ll run another test on Monday when I’m off, or tomorrow in the garage at work.
looks like I’ll have to try replacing that part. But can you answer me this, is it something urgent to fix? If that part fails will everything still run ok?
No emergency to fix it, as long as you don't hear "tapping" noises from engine when gauge is bouncing the oil pressure is OK.
Under about 3psi oil pressure the upper engine rockers and lifters will not get enough oil and will start to make a tapping or ticking noise, which can mean parts will start to wear, and that oil pressure is actually low
Ok I’m ordering the motorcraft part even though it’s iver double the price of the others...
Its just so strange to me that it only does this after a long drive and not all the time. Not sure why it would do it only after long highway trips and not right as I start the truck if the problem was actually the sensor. I can let it get warmed up and drive for a half hour in town and it won’t happen. But if I take it on the highway and drive hard for 15 minutes and come to an idle it’ll start...
**** I hope so. I’m gonna check tomorrow when I’m off and it’s dry out. Raining in Seattle today and I’m working. I hope that’s the case. If it’s loose then what can I use to attach it better? Does it just slip on over the threaded post thing? Or do I use something to attach it?
I see some videos where people have a plastic snap on thing on the end of the part but the part I’m ordering doesn’t have that. I attached a picture of the part I’m ordering. Do I like take that plastic connector off my old one and screw it onto the post of the new one? I’m so confused by this. As you see in these two pics, one has the plastic part and the other has just the threaded post.
Just have to look at it, not sure what fitting/connector would be on a 1992 3.0l.
You have to remember what "fits" and what you have can be 2 different things.
Pretty much any oil pressure switch will "fit" the hole size, the wire connector is the part that changed over the years
i.e. "Fits 1992 Ford Ranger 3.0l" doesn't mean it "fits 1992 Ford Ranger 3.0l connector", lol, I know, but just the way it is, 90% of the time you get lucky, and thats what it is, luck
You’re right it has the correct end. But it’s impossible to get out. Not enough clearance for a socket to get over it and the tranny dip stick line is too close. The fire wall is right there next to it. It’s impossible to take out without removing the entire motor. Here’s some pics.
It can be pulled out with the right tools, may be claw foot wrench.
The threads are tapered so it just needs to be loosened, then it can be done by hand, or in this case 'finger', lol
Get the new one and stop by a mechanics shop, ask them how much to change it, CASH, if they have the right tool its a 10 min. job, including coffee break
Pop back at closing time and its done
I own a couple of rangers. The one in question is a 1992 3.0 V6 Automatic.
Only after long drives on the highway my oil gauge starts bouncing while idling in drive. If I tap the gas the needle goes back to the middle, but once it idles again it again bounces.
It bounces between the middle and low, never all over the place, just between low and normal.
When I turn the heater on it causes it to bounce harder, it gets lower to the L when I turn the fan on higher and higher. The load seems to effect it as well.
Any ideas on this? Some people say its the oil pressure sending unit or regulator, but a lot say it didn't fix their problem. Some say it could be the alternator, which might make sense since it does it even more under load. But my battery has never died in the year its been doing this. However my battery is 9 years old... it still has 300 CCA and the battery guy said its still good to use and I don't need a new one.
Any help is appriciated!
I'm having the exact same issue with my 2003 ranger. After driving for a while, if i turn on the heater or a/c, my oil gauge will bounce from the middle to the low side. Issue resolves itself when i turn the heater or a/c off. Did you figure out what the issue was?
I never fixed it and it still does it I’ve put 50k on the truck and it’s done it from the start. I KNOW it is the oil pressure sending unit.
this does not effect the oil pressure whether working or not. It simply lets you know if there is pressure or isn’t. It’s not a gauge really. If there’s any sort of pressure, it’ll sit halfway, if none, it’s down. When the sending units fault then weird **** like this happens.
this is all my assumption via experience with this.
i notice when I also do the heat it’ll make the already slightly shaking needle surge even lower. I swear I hear the idle change and **** too..
I'm having the exact same issue with my 2003 ranger. After driving for a while, if i turn on the heater or a/c, my oil gauge will bounce from the middle to the low side. Issue resolves itself when i turn the heater or a/c off. Did you figure out what the issue was?
I have a '99 that does it too.
I'm pretty sure it's just the sensor, as everyone else said. ...She runs smooth and cool, so I'm not gonna worry about it for now.
I used to have an '87 with the 2.9L ... On that one, the needle didn't even bounce around at all. It just laid flat in the red zone all the time...
When I asked about it on forums, a lot of people said "it's common", "don't worry about it", etc.
So I didn't worry about it, and I drove that truck for years.
03-01-2018
