Oil gauge "needle flicker"@Idle 02 Ranger

greenrangerte49 · #1 10-13-2009, 11:15 AM

2002 Ranger XLT 4X4 Offroad 3.0V6 NOT Flex Fuel Automatic Motorcraft 400SL oil fiters&5W20 Moto.changed OFTEN(3000 or less!)almost 99,000 miles.Except for service under warranty,ALL my own work!My Oil sending unit,I've replaced twice,and the Oil Gauge needle stopped "flickering" for a few weeks? I didn't keep close tab on it,figuring ,I fixed it? It Only Originally for ,several years now,On LONG trips!Say 100 or more roundtrips,I'd get a Oil gaiuge needle "wobble","flicker","Jump",whatecer ,ONLY after these extended trips,after stopping to idle!Never when Cold or short "jaunts" to nearest town(35 miles!)Clean,topped off oil too! NEVER saw the Oil level low! Doesn't use any,or insignificant amount.No Engine noise,although ,My Camshaft Synchronizer,had some "chirping" ,so I oiled it.But that's recent.Replace the gauge? Waddyas TINK?

turbo · #2 10-13-2009, 11:42 AM

I *think* that what you actually have (unless you've modified it otherwise) is an oil pressure indicator, disguised as a gauge. A real oil pressure gauge would not constantly read mid-scale, without fluctuation, regardless of incline, RPM, etc. The oil gauge in the (stock) Ranger is an idiot light with a "gauge" for a light.

...and, the problem is (largely) in the sending unit, not the gauge itself. The sending unit, in essence, sends "yes" or "no", and nothing in between. If memory serves, the "no" doesn't get triggered until the oil pressure drops below 6 [yes, you read that right: an oil pressure reading of 40 looks the same as an oil pressure reading of 7 on this system!]. I have seen, and perhaps it will make its way to our "How-To" section here, a write-up on replacing the oil sending unit and tweaking/calibrating the stock oil gauge to get a -real- reading.

As for your original problem, if you've already traded out the sending unit once or twice, and still see the "wobble", it could be the gauge that needs some repair work or replacement. I would recommend seeking out and employing a real fix, as I outlined in the previous paragraph.

FireRanger · #3 10-13-2009, 01:37 PM

Correct. The oil pressure is only a switch that closes at 7psi. It is wired the gauge through a resistor behind it that applies the correct resistance to the circuit that will put the needle right in the middle. If you put in a sensor rather than a switch and jumpered over the resistor, you would have actual oil pressure on the gauge. But the way it is designed right now, the needle only has two settings: 0 and Middle.

Given that, the only way the needle would flutter is if the pressure was hovering around 7psi causing the switch to open and close quickly (not likely) or there is a wiring problem. Wiring problem is more likely. Check the harness connected to the oil pressure switch for loose or frayed connections.

turbo · #4 10-13-2009, 02:35 PM

Quote:

Originally Posted by FireRanger

Given that, the only way the needle would flutter is if the pressure was hovering around 7psi causing the switch to open and close quickly (not likely) or there is a wiring problem. Wiring problem is more likely. Check the harness connected to the oil pressure switch for loose or frayed connections.

I wouldn't say that's the only way it would flutter. Perhaps the most probable. Another option is that the tolerance of the resistor going to the "gauge" is varying (due to age, heat, or physical damage) and causing a slight variation of where 'middle' is...

greenrangerte49 · #5 10-13-2009, 02:54 PM

Thanks there,Men! No Modifications,ALL Stock gauges."Idiot gauge" Confirmed! High-Low! Will check wires too! VERY consistant though,ON these LONNNNG trips,Farthest ,I've been in years to VA Hospital!130 miles roundtrip.When ,I've been on the Freeway at 65-70MPH ,Lookin Good! Pull off to Ramp to Stoplight,Voila,Needle dances Like A "Turkish Belly Dancer"Back&Forth,AND straightens out,as soon as I touch the Gas pedal!Drive on these mountain highways home 55MPH or so ,get home ,stop at Trailer Park Office,"Flickers" again! Rev slightly,Goes away!Will check wiring etc.Thanks again!

Iwejun · #6 11-15-2012, 01:37 PM

Mine would flicker also until I changed to Amsoil synthetic 5w-20 and added Zymax to the oil, on mine it didn't happen overnight , but within 500 mi. the problem went away and I haven't seen it since. I believe the Zymax in the oil penetrated the oil sender switch and helped stop it from sticking. Just my experience.

shaund · #7 03-13-2013, 05:58 AM

I have a problem with my oil pressure gauge , take in mine this is my first ford n first truck but when I go out to start my ranger the check gauge light comes on and the oil pressure gauge its like its not working after running for a few it the check gauge light goes off and the oil gauge go to the middle , the oil n everything is good not low or too much ... Does anybody have any idea if this is a prob. Or anything would be very appreciate

99Ranger376 · #8 03-16-2013, 07:36 PM

Mine did that and the needle would also flicker once in a while I replaced the oil pressure switch and the connector because it was rotten and it fixed the problem got the parts from eBay for about $25