Oli pressure sender

The computing system on your vehicle has no safe mode for running low on oil . The only thing that will happen is the check gauges light will come on.
The oil pressure gauge is an analog device that is located in the IPC. The oil pressure gauge is operated directly by the oil pressure sensor circuit. As the engine oil pressure changes, the resistance of the sensor and the current flow in the oil pressure gauge changes. The current flow in the oil pressure gauge causes the needle to move in order to appropriately display the engine oil pressure. A sensor resistance of 1ohms will display as 0 kPa (0 PSI) and a resistance of 88 ohms will display as 80 kPa (80 PSI ). The IPC also monitors the oil pressure sensor circuit and interprets the current flow in this circuit in order to determine when the engine oil pressure is too low. If the oil pressure is too low, the check gauges tell tale will turn on. The oil pressure sender is located on the left side of the 2.2L. The 4.3L engine, oil pressure sender is located at the top left side, near the distributor/high voltage switch.
Try disconnecting the battery cables an hold them together for ten minutes , reset ECM !

If no noises from engine it's likely possible that the oil pressure switch went bad. If you don't change you oil often there's a possibility that there may be sludge build up and possibly clogging the pick up. If you go more than the recommended amount of mileage/time between oil changes I would recommend an engine flush.

Location of oil pressure sender unit depends on what engine you have. There should be one wire going to sender, and if it has come off, gauge will read zero. 4.0 inline 6 has sender low on passenger side of engine, above the starter.

Make sure oil level is full, possible faulty oil pressure sender. replace sender and recheck, if warning still comes up, possible internal engine issue.

this is a common sign of a bad oil pressure sender, but could also be caused by low oil pressure, a sender is cheap,but it"s always smart to do a pressure test first with a mechanical gauge,you can obtain a mechanical gauge from most automotive parts stores. then you"ll have to locate and remove the oil pressure sender and install the gauge you bought. make your test at warm idle you should have at least 25 psi below that you may very possible have worn engine bearings making it impossible for the engine to have any better oil pressure at idle. if you have 25 or greater psi of pressure at idle replace your oil sender and you"ll be back on the road

Fig. 1: Location of the oil pressure switch-3.3L and 3.8L engines




Fig. 2: Location of the oil pressure switch-3.0L engine

Fig.: Oil pressure switch (sending unit) schematic


The low oil pressure warning lamp will illuminate when the ignition switch is turned to the ON position without the engine running. The lamp also illuminates if the engine oil pressure drops below a safe oil pressure level. To test the system, perform the following:

1. Turn the ignition switch to the ON position.
2. If the lamp does not light, check for a broken or disconnected wire around the engine and oil pressure sending unit switch.
3. If the wire at the connector checks out OK, pull the connector loose from the switch and, with a jumper wire, ground the connector to the engine.
4. With the ignition switch turned to the ON position, check the warning lamp. If the lamp still fails to light, check for a burned out lamp or disconnected socket in the instrument cluster.

REMOVAL & INSTALLATION
On the 2.4L engine, the oil pressure switch is located on the side of the engine block facing the firewall. On the 3.0L engine, the oil pressure switch is located on the oil filter adapter housing, next to the starter motor. On the 3.3L and 3.8L engines, the oil pressure switch is located next to the oil filter.

1. Locate the oil pressure sending unit on the engine.
2. Disconnect the negative battery cable.
3. Disconnect the pressure switch electrical harness.
4. Using a pressure switch socket, deep-well socket or wrench, loosen and remove the pressure switch from the engine.

To install:

1. Install the pressure switch into the engine and tighten securely.
2. Attach the electrical connector to the switch.
3. Connect the negative battery cable.
4. Start the engine, allow it to reach operating temperature and check for leaks.
5. Check for proper oil pressure switch operation.

Hope this helps (remember to rate this answerr).

Not sure of your engine size so please pick the appropriate diagram:

Coolant temperature and oil pressure senders-4.3L engines

Coolant temperature and oil pressure senders-5.0L and 5.7L engines

Coolant temperature and oil pressure senders-7.4L engines

Coolant temperature and oil pressure senders-6.2L and 6.5L diesel engines

You need to verify that oil pressure is ok.
They sell gauge at the parts store which has to be connected to the engine block via oil pressure sender hole.
For that , take out oil pressure sender(unscrew) and screw the gauge in to the hole (con thread).Run the engine and see if pressure is ok at idle and on higher RPM.Gauge suppose to have scale (norm. , low , high ).If oil pressure within specs , repl. oil pressure sender.
Or just replace oil pressure sender and see if that helps.They are not expensive ~ $30.00 , gauge probably the same money.

Providing there is no engine noise when pressure reads low likely either the connector on your oil pressure sending unit is loose or the sender itself is failing. Check wire connection and if good, replace sender. If there is engine noise, likely you have an internal pressure problem that generally is caused by obstructed pump screen or worn engine bearings. Oil level is full?

I think you have a suspect oil pressure sender unit. Replace it as they are cheap and need to be reliable and it will be cheaper than getting the oil pressure tested. If the light still stays on with the new sender you may have internal wear or a partial blockage. If the light stays on you need to have it urgently checked by a mechanic or you could risk serious engine damage.