After hours of searching,I learned that there's a Voltage Regulator for the dash Instruments?My 02 Ranger 3.0V6/AT 4X4 XLT ,has been having an oil pressure gauge anomaly.It's been happening after longer trips:50-100 miles or so.After the long trips,I come upon a stoplight or stop at stores,etc.,and the "needle" on the Oil pressure gauge,"FLICKERS",like it hadn't had a "Drink"for hours of "Binging:"Shaking,back&forth ,like a "Turkish Belly Dancer"!When I Rev slightly,it is steady again!Upon arrival home,I park her and "Flicker"!Oil level:Full,Always changed at "proper" intervals+New Filter too(RECENT!) Recommended Ford Motorcraft 5W20 or 5W30 Syn.Blend used.Oil is lookin clean&Full! I'm thinkin sender/pressure switch ,and buy one for less than ten bucks $$! Haven't replaced it yet ,do to my Morphine pump implant(right side ,where i usually lie)!,and Hip repair in 99! Can't just "scramble" out there crawling around looking for the sender,until I'm positive ,it's My "Baby"!Now I'm "Eyelid Droopy" after this extensive search,and "New" data about an instrument cluster voltage regulator?"MINI-POLL"? Volt.Reg. OR pressure switch/sending unit?Perhaps?Both? TankU2Much!

 

Poll answer, both,

Throw in the gauge too, and the grounds they are attached to.

 

Well if this only happens after a long drive, maybe add oil viscosity or oil foaming to the suspect list.

Any engine noises asociated with the gauge flickering????

The gauge is set to read midscale when the oil pressure reaches about 7 psi, so if the pressure switch is ok & you are hearing any engine noises when it flickers, I'd consider removing the oil pressure sending unit & attach a shop mechanical gauge to read the true oil pressure, so you can determine whats going on.

If it just started happening after this last oil & filter change, also add the oil filter to your suspect list.

So which viscosity oil does it now have in it & is it the same viscosity & brand you've always used & are you using the specified Motorcraft oil filter???

If everything else checks out, on the instrument side suspect list, the oil pressure switch fails most often, so it probably belongs close to the top of your suspect list.

More thoughts for pondering, let us know what you find.

 

Let's start a Bank too! Now all I need is some "Green Frog Skins"/Bucks/Dinero/Greenbacks/$$$$!!! All kidding aside,"Being Retired Ain't FinanciallyHealthy to Me"!<"BUT'I get to watch the Commutes to Work Everyday&Thank God I Ain't In Em!ThanksFor you "Responsivo Rapido"!Live Free or Die!,"An Appeal To Heaven"!

 

It did this off & on for a yearvor two.I use almost exclusiely 400SL Motorcraft filters unless otherwise unavailable,I used Fram once or twice.The Only Noise issue "WAS" my Cam Synchronizer",I have The part.It "Quit" the noise,but "Yeah I know",gotta do it NOW!"But it doesn't make noise or didn't while driving ""Hot"! The Oil pressure "flicker" at the gauge needle was so intermittent.It made noise(CamSync) on Cold Startups,then stared "Singin" even Hot.But Not noticeably while the gauge needle"danced"!No Noise whatsoever ,yesterday on my Long Haul to Doctors.Only that Gauge flicker after driving a while.I'm using Motorcraft 5W30 now,they don't always have recommended 5W20! I live waaaaaaaaay out here in the Mountains across from the "highest" peak in SanDiego County.shopping options are VERY limited.Can You believe 50 miles to WalMart!Thanks Folks!Got Me On Track Here,Now Time to "Dream" about "Trucks&Money" ,A "New" song I'm writin for Toby!

 

Because of my Warranty concerns,I've stuck with Motorcraft&the 5W20 Motorcraft Oils.Now that ,even tho I "had" extended warranty,I still use the same Motorcraft oil&Filters.Unless,lkie I said ,Unavailable within 75 miles!Now with 96000 miles(sorry forgot to mention!),Still on Motorcraft ,Drive as usual,same routes,etc.Can't think of anything else but what you've provided,unless that "Cam Sychronizer" is "Tied in" ,somehow? Thanks Again,Been A Long night!Fell asleep during last night reruns,Got UP! Jump on: Computer!

 

After I took A friend To VA clinic,I checked My Oil after that 40 mile drive,FULL ,CLEAN<Viscous OIL! I didn't notice,nor look at that time for the "Flicker" until I drove the 40 Miles back home!I think I mentioned I changed it 2000 miles ago and almost three months since.Lookin Good Visably!I Got the Seder/Switch gonna price the Instrument? Cluster regulator(Voltage),just in Case."Out Here" You DO NOT want to "break Down",Who does!But here it can Cost your Life,There's NO room to pull over where some of these slopes /cliffs ,come right down to the edge of the Road.Stop there&One "Speeder" will "NAIL You!Even Tires make me "paranoid!Flats,that is.I giot new ones ,but caught a 8Penny nail here in our Campground(Camper firewood)!TENFOUR "Until,We Meet,Agin"!(Gene Autry)

 

OK, Motorcraft oil filter & motor oil, thats good & I assume it's NOT overfilled & you didn't notice any foam/bubbles on the dipstick when you checked it after the long drive & the gauge was acting out.

On the noise, I was thinking more along the lines of lifters, or main bearings being noisey, when the gauge acts out after the long run.

If so then suspect an oiling problem, could be foam from overfilling, or too low a viscosity for the oil pump to circulate( probably not the case with the Motorcraft 5w-30), or a filter problem, but not likely with the Motorcraft filter, unless this just happened after this last oil change, in which case maybe you got a faulty filter.

It acting out after extended drives is a clue, but i'm not sure where this piece of your puzzle fits just yet.

Do I understand the oil pressure gauge has been doing this for a couple of years????

Does it ever do this when the engine is cold, before the oil has had a chance to come to full operating temp?????

If not, I'd maybe put the oil pressure switch at the top of your suspect list.

 

Thanks Paw Paw,NOt overfilled,Perfect dipstick reading after long haul&Parked at VA clinic for half hour!No foam or bubbles,GOOD clean Motorcraft Oil!No noise when gauge "Flickers" ,My Noise WAS from the Camshaft sycnchronizer.Never when Cold.Yes for year or two!Got Sender,will try that&check/replace gauge if necessary.SEE NEW reply: No IVR on NEW gauges (Built IN!)I belive after almost 24 hours here off&on,I'm outta here! Thanks Folks!

 

My Haynes doesn't show sensor/sending unit lovation?And Autozone Repair guide ONLY shows the "Bigger" V6 location.Where Da Heck is it on my 02 Ranger 4X4 3.0 V6 w/o Flex Fuel? I've looked & looked ,can't find it?

 

The Vulcan sending unit is at the back of the engine, on the top, near the bell housing. On the passenger side, rearward of the cylinder head, next to the distributor if you have one.
tom

 

Thanks again ,tomw! I saw the sensor/sender ,bak there,NO distributor(Camshaft synchronizer/canshaft positioner).2002 Ranger XLT 4X4 Offroad w/3.0L. V6 & Auto trans.It looks "pretty hard" ,to get to? I'm not a "contortionist",but will do my best.I do ALL my own work,with few exceptions.I have some health issues that won't permit some manuevering however.Since per my previous post:Camshaft Sychronizer("Chirping")etc.,I think I better get on that first.At least attempt the "Oiling" the Bushing ,etc. I have the part but somewhat unsure,lacking self-confidence ,lining up the Crank pulley TDC!

 

I "threw" An outdoor carpet over the whole engine,and "laid across it.Replaced that "Bad Boy" and Road tested it today with at least a 60 mile drive,VOILA!No more "needle movement(flicker)!Thanks Everyone!This forum is like Haynes/Chilton and a Brother-in-law Ford tech,ALL in one!I just work on Truck,come in ,ask questions,and All is well!

 

I forgot to mention? I got a sensor 'Zone,and that did it!One puzzling technical qusetion,I need answered? Why No Oil on sensor? Not A Drop! Nor any sign of trace amounts?

 

The sensor is at the top of a "column" drilled into the block. Said column is filled with air from the factory after it is drilled. The oil compresses the air and pushes on the sensor, w/o actually letting the oil come to the top of the passage. If the air got out, you'd have oil getting out, too.
That's my guess...
tom