Ford f250 gauges change when I turn the headlights on

SOURCE: Oil pressure gauge

sounds like the sending unit or wiring for the gauge is shorted to ground

SOURCE: oil pressure gauge reads past 80

now unless there is a very loud knocking of the motor which would mean that the engine's top end was not getting any oil I would say that your oil guage is sprung and needs replacing. a high pressure rating would indicate a restriction in the oil flow pasdt the sending unit or a plugged oil filter. if the filter were plugged you would know it because your enging would run tight in no time at all. replace the guage itself... please rate this........thanks

Johnny Massengill

• 345 Answers
• Posted on Nov 10, 2008

SOURCE: OIL PRESSURE LIGHT COMES ON AND PRESSURE GOES TO 0 ON GAUGE

Any time the oil pressure is 0 you take a chance of locking up the motor. The only way to know for sure is to put a pressure gauge in the oil pressure sending unit port on the engine and see what the pressure really is. At that point you will either have the peace of mind in the knowledge that the sending unit is really bad and needs replacement or you can then contact a repair shop and tell them what your testing has revealed. I wouldn't drive or run your truck while the oil pressure is at zero.

Good luck

SOURCE: Oil Pressure going up and down during acceleration and decel.

Hi, this is a faulty oil pump and , it should be replaced asap. make sure the mechanic replaces the oil screen as well.

You can test the pressure gauge and True oil pressure by using the guide below.



Testing the Oil Pressure Gauge

* Test the gauge by grounding the wire that leads to the sending unit on the block.
* When the wire is grounded with the key switch on, the gauge should show maximum oil pressure, or the light should go on.
* If either happens, the gauge and wiring are good and the sending unit is at fault.

Testing Oil Pressure

Pressure can be tested by temporarily installing an oil pressure gauge in place of the sending unit. Before testing, look up the oil pressure specifications for your vehicle in the appropriate service manual.

* Bring the engine up to operating temperature.
* Now shut the engine off.
* Locate the oil pressure sending unit; usually it is on the lower side of the engine block.
* disconnect the wire from the sending unit and use an Open Ended Wrench to remove the sender. using pliers can damage the unit.

* Tighten the oil pressure test gauge into the hole in the block where the sender was removed.

* Check the engine's oil level and fill, if required.

WARNING
Be extremely careful when working near a running engine. Always wear safety goggles or glasses with side shields when working around moving machinery and be sure that your clothing is not loose.

* Now turn the engine on and check the oil pressure on the gauge.
o Watch as the engine warms to note any excessive drops due to temperature.
o Make sure the engine speed is set to specifications for testing pressure.
o if necessary, us a Tachometer and adjust the engine idle speed.
* Record the measured oil pressure, then turn off the engine.
* Compare the test results with the manufacturer's specifications.
o If the oil pressure is within specifications, this shows that the oil pressure sending unit may not be working correctly.
o In many cases, replacing the oil sending unit will correct the problem.
* After the test is complete, reinstall the oil pressure sending unit, start the engine, and confirm there are no leaks.

SOURCE: low oil pressure 93 GMC P/U w/350 motor w/205,000 miles gauge

While engine is running, open the cover where you add oil to engine and see if you see a good flow of oil, if good flow, could be as easy as replacing oil sending sensor. got to realize that if poor maintenance history your engine may not be building enough pressure at iddle to move your hydraulic operated valves, only when you rev it up it will pump enough to run smooth. if running engine too long, you may cause more damage to other engine components such as crankshaft and cam shaft bearings. if you can spare a few bucks, have a good mechanic check your oil pressure with a mechanical gauge. another cheap option is to replace oil pump. last resort if you love your truck as much as we do,replace engine or rebuild it. At 205,000 this is a normal symptom, other than timing chain problems, most engines don't make it that far. hope this helps!