Flashig oil light

You need to find out why you have low oil pressure. It is normal that as engine rpm's increase, the oil pressure will rise- the oil pump is moving oil faster. Even though your light goes out, you could still have critically low oil pressure. There should be sufficient pressure at idle to keep the light off. The light will come on when your oil pressure is almost nil- I believe for some it's as low as 8 psi. Normally, oil pressure at idle is specified anywhere from 15 to 40 psi. You would have to check specifications for your Expedition. To verify oil pressure, hook up a mechanical gauge at the oil pressure sending unit on the engine block. Check with a local shop.

The causes run from easy, simple to budget busting ruin. Low oil level, wrong grade oil, real old oil, oil leaks, internal oil leaks, worn oil pump, worn crankshaft bearings. It was pretty common on older very high mileage cars to have a fluttering oil light at stops and idle. It was time for a rebuild, or time to look for another car.

When engine is idling the oil pressure sign can come up and that is OK. However if you've noticed that gauge shows much lower oil pressure that a bad sign. Show it to knowledgeable mechanic (but don't be lured in the engine replacement; ask for a root cause - it may be oil receiver or oil pump). Also I hope there's no oil puddles under the car? What about oil level?

First check your coolant level. If it is low, look for leaks. Also don't rule out the reservoir isn't bad. Also if the hose is pinched to reservoir, this will cause low coolant in the engine.

It could be one or more of the following; clogged oil screen (pan must be removed), Excessive sludge or the oil pump. When the oil pump is going bad it shows at low rpms. ps it is also possible that your dipstick is giving a false reading- showing a false normal operating level. Good luck!

see this tips and fix it. God bless you
The oil pump supplies oil to lubricate your engine. If the oil pump is worn or is not turning, the engine will suffer a loss of oil pressure, which may result in engine damage or engine failure.
The first sign of trouble may be a low oil pressure warning light, a drop in the normal reading on you oil pressure gauge (if your car has one), or the appearance of ticking or clattering sounds from your engine.
As a rule, most engines only need about 10 PSI of oil pressure for every 1,000 RPM of engine speed. Oil pressure will read higher than normal when a cold engine is first started because the oil is thick. Oil pressure will gradually drop as the engine warms up and the oil thins out. So normal oil pressure on a warm engine cruising down the highway is typically 30 PSI up to 45 PSI.
SYMPTOMS OF OIL PUMP TROUBLE
The first thing you should do if any of these symptoms occur is to stop your car, turn off the engine, let it sit for a few minutes, then check the oil level on the dipstick. If the oil level is at or below the ADD line, add a quart of oil to bring the level back up to the full mark. Add as much oil as is needed to raise the level to the full mark. Then restart the engine. If the warning light remains on, or the oil pressure reading does not climb back up to its normal range, or the engine noise does not go away, you may have a bad oil pump.
The other possibilities include a bad oil pressure sending unit, or a problem with the oil pressure warning light circuit or oil pressure gauge.
OIL PRESSURE SENDING UNIT
If the engine is NOT making any unusual noises and seems to be running normally, and the oil level on the dipstick is FULL, but you are still getting a low oil pressure warning light or low gauge reading, the fault could be a bad oil pressure sending unit.
The oil pressure sending unit is mounted on the engine block. On some applications, there is a spring-loaded pressure-sensitive diaphragm with a switch inside the sending unit. This switch completes the circuit to the low oil pressure warning light if oil pressure drops below a certain threshold. The unit may stop working if the diaphragm inside fails, if the switch is stuck, if the small hole that allows oil to enter the sending unit becomes plugged, if there is a loose, corroded or broken wiring connector at the sending unit, or there is a fault in the wiring circuit between the sending unit and warming light.
On vehicles that have an oil pressure gauge (electronic, not mechanical), the oil pressure sending unit has a small rheostat inside that sends a variable voltage signal to the oil pressure gauge when the diaphragm moves. A worn spot on the rheostat or any of the other problems just described for the simple pressure-type oil pressure switches can cause a problem.
FORD'S FAKE OIL PRESSURE GAUGE
On many Ford vehicles that were built from 1980 through the 1990s, the oil pressure sending unit has two switches, a low pressure and a high pressure. These vehicles also have an oil pressure gauge, but the reading on the gauge is not a true indication of real oil pressure. As long as the pressure to the sending unit is between high and low, the gauge will read normal. If oil pressure drops and trips the low pressure switch, the dash gauge will now read low. Or, if oil pressure goes up and trips the high switch inside the sending unit, the dash gauge will read high. Consequently, don't rely on the oil pressure gauge for an accurate reading in these vehicles. It is only a gross indication if the oil pressure is low, normal or high.
OIL GAUGE PROBLEMS
If the engine is NOT making any unusual noises and seems to be running normally, the oil level on the dipstick is FULL, and you have replaced the oil pressure sending unit but are still getting a low oil pressure reading on the dash gauge, the fault could be in the wiring circuit between the sending unit and gauge, or the gauge itself might be bad.
Check the wiring connections on both ends as well as wiring continuity between the sending unit and gauge. If no wiring faults are found, hook up a pressure gauge directly to the oil pressure port on the engine and check oil pressure with the engine running. If the engine-mounted gauge shows normal oil pressure but the dash gauge is reading low, the problem is a bad dash gauge.
On the other hand, if the engine-mounted pressure gauge reads low and you have done all of the above, chances are the oil pump is worn, or it is not picking up enough oil because of a restriction or blockage in the pickup screen in the bottom of the crankcase.
OIL PUMP PICKUP PROBLEMS
The pickup tube has a screen on the end to prevent large chunks of anything bad that ends up in the crankcase from being sucked into the pump. But we are talking BIG chunks of debris, not normal wear particles or carbon or dust or other microscopic-sized abrasive particles that can cause pump wear over time.

Oil pressure and oil level are two different creatures.

your oil gauge determines oil pressure while the oil can (red light on dash) indicates oil levels.

There are usually two different sensors but can gauge the same types of things. E.G. - If your oil is so low that your pressure gauge is affected this can cause engine failure. Thus--a good rule of thumb is to check your oil once a week as the oil pressure gauge and red oil can may not always work as intended.

I hope this helps!

I recommend having the oil pressure checked by a technician with a pressure gauge. Lets make sure the pump is creating enough pressure. If pump checks out then its theoil pressure sending unit, gauge or the circuit

It sounds like your engine is low on oil. When you get home, turn your engine off, wait 5 minutes, the pull the dipstick and wipe it clean and re-insert fully, then pull the dipstick out again and look at the end of it; you will see the recommended level etched into the dipstick, if the oil level shows low (and it's a good bet it will), you need to add oil...and never use that shop again.

If the level is normal, the oil pressure sender may be faulty...ask your mechanic to check it and replace it if necessary.

The oil light indicates that the engine's oil pressure has dropped below the minimum safe pressure. When the light goes out it suggests that pressure has been restored to a sufficient level for engine lubrication but this is nevertheless a bad sign.

I suspect that the oil level in the engine is too low and that the oil itself has greatly deteriorated and has not been changed for some time.

1. Check the oil level again, after the car has been standing for a few minutes, and make sure the engine oil level is at the maximum mark on the dip stick. If not then top it up.

2. Have the oil (and oil filter) changed in the car as soon as possible and ensure it is the correct spec viscosity oil for that engine .

3. Brake test the car to see if the oil light still comes on under braking.
If it recurs you need to have an oil pressure gauge hooked up to the engine (by an auto repair shop) to see what oil pressure is being achieved at various engine revs. If an independent gauge shows no problem with oil pressure then I would assume a faulty oil pressure sensor.
If the pressure gauge identifies a lower than normal oil pressure in the engine's lubrication system then the cause needs to be identified and fixed.

Sean

First thing I'd check is the oil level, coolant level. The check gauges light is illuminating because on of the gauges is below a certain pre-programmed threshold. The light is very similar to the old idiot lights that came on when it was too late. Cars used to have gauges and in the earlly 90's the manufacturers figured out that the majority of owners did'nt even read the owners manuals, let alone know how to read a gauge. So they started putting in idiot lights that would come on when there was a problem, they figured even an idiot could see a red light on and know there was a problem. The only problem was that the pressure switches that turned the lights on were set very low. Take for example an oil pressure switch (OPS). The switch is designed to close and complete a path to ground for a light, the problem is it closes aroung 3psi. Normal oil pressure is around 30, at 3 psi the cam and crank bearings are starving for oil, by the time you see the light on it's too late, the damage has already been done to the engine. So the manufacturers started installing gauges and lights to cover all the bases. So if I had to take a guess, I'd say you have and oil pressure problem. Check the oil, if it's low figure out where it's going, if it's not then you may have a faulty sending unit, confirm this by installing a manual oil pressure gauge in it's place. If the manual gauge shows low oil pressure then there may be some debris/sludge floating around in the oil pan stopping up the pickup screen or it could be a faulty pump.