Where is the oil pressure sending unit - Cars & Trucks

Flashing oil light indicates a loss of oil pressure. No oil pressure will cause the engine to seize up. Check the oil level, if full verify that the oil sending unit is connected correctly. Listen for unusual engine noise (Shut down immediately to avoid damage to the engine), connect an oil pressure gauge to the oil sending port (remove sending unit) and verify oil pressure. the issue could be a loose connection, broken connection or plugged sending unit, as well as loss of oil pressure.

first need to buy oil pressure sending unit 3/8 deep socket remove oil pressure sending unit you need teflon tap sealer for oil sending unit threads.okay to replace oil pressure sending unit.you need safe raise support vechicle locate oil pressure sending unit next to the oil filter.disconnect oil pressure sending unit wire connector then use oil pressure sending unit 3/8 socket remove the sending unit.then take new oil pressure sending unit use teflon tape white plumbers tape or use thread sealer apply to the oil pressure sending unit threads then install new oil pressure sending unit and reconnect electrical connector to sending unit.then crank engine check for oil leak if all is good lower vechicle back to ground wait several minutes check engine oil level.you good to roll.

THE ENGINE IS GETTING OIL AS LONG AS IT IS JUST YOUR SENDING UNIT. THE SENDING UNIT JUST SENDS OIL PRESSURE READINGS TO YOUR GAUGE OR IF YOU HAVE AN IDIOT LIGHT IT KEEPS IT OFF AS LONG AS YOU HAVE PRESSURE.

The sending unit is a variable resistor. When the oil pressure is normal only a small amount of voltage goes to ground through the sending unit. As the oil pressure goes down, more voltage is shunted to ground reducing the sending unit voltage and causing the gauge to indicate a lower pressure. If the oil pressure falls very low or disappears the sending unit shunts all the voltage to ground which causes the dash indicator to show no oil pressure.
Now if the wire to the sending unit gets nicked, melted or cut and finds a short circuit to ground, or gets disconnected in a junction point between the gauge and the sending unit, you will get the same no oil pressure indication from the gauge.
Check you wiring for a short to ground or an open connection.
The same

in order to check the oil pressure, you have to remove the oil sending unit, then screw in the adapter of the oil pressure gage, and then remove the start relay or fuel pump relay from the fuse and relay box, under the hood on the drivers side, and then crank the engine over 3-4 turns, and then record the oil pressure, and then disconnect the oil pressure gage, and then re install the oil sending unit, replace the start relay or fuel pump relay, and then start up the car, and check the oil sending unit , to make sure it is not leaking, if your oil pressure checks out within the specs, then you are fine, if it gives you a low reading, then you could have a bad oil sending unit , or a oil pump going bad on you. i would replace the sending unit first, then see what the gage shows.

either replace oil sending unit or get a manual oil pressure gauge and screw in to oil sending unit port and visually check with engine running to see if or what the actual pressure is. If 0 pressure registers then bad oil pump. but if good pressure, then you have a bad oil sending unit. also change oil filter.

spend the 12 dollars and get a universal mechanical oil pressure gauge, remove the oil sending unit on truck and screw new gauge into and start truck. Does it read pressure? I know people will say just replace oil sending unit but i like to visually check for a true oil pressure than to trust a light, at least you will know what pressure your motor has. if you have pressure then replace the sending unit. Most of the time when the sending unit goes bad your oil pressure gauge in the truck will run at 80 psi all the time. Since you have a light the sending unit just says it isn't getting pressure which turns a light on. So be safe and do as i suggest, if there is no pressure at the mechanical gauge then i hate to say it but you may have a bad oil pump. I honestly just think you have a bad sending unit,if you want just replace it and if lights go off thats good, but you still don't know what the pressure is and if you feel comfortable with this then do so.

Oil pressure can be checked at the sending unit passage with an externally mounted mechanical oil pressure gauge. To get accurate results from the test, make sure you follow the manufacturer's recommendations and compare your findings to specifications.
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 disconnected from the sending unit with the key switch on, the needle on the oil pressure gauge should be either all the way high or all the way low. Grounding the wire should make the needle move to the opposite side of the gauge from where it was before the wire was grounded. If the vehicle is equipped with an oil pressure light, touching the wire to ground and then removing the wire from ground should turn the light on and off.
• 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.

An oil pressure sending unit is removed with a special socket. Courtesy of Chrysler Corporation.

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

Measuring oil pressure. Reprinted with permission.

• 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.
  • Watch as the engine warms to note any excessive drops due to temperature.
  • Make sure the engine speed is set to specifications for testing pressure.
  • 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.
  • If the oil pressure is within specifications, this shows that the oil pressure sending unit may not be working correctly.
  • 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.

The oil pressure sending unit is located on the engine block, passenger side by the Distributor. Good luck and make sure you get the right sending unit, there is the simple unit that only turns on a low oil pressure light and the other will send signals to the oil pressure gauge.

Oil Pressure Switch Operation:
Information relay unit for the indicator light or gauge on instrument panel. It contains a diaphragm that responds to changes in oil pressure. When the oil level is over a pre-set limit, the diaphragm opens the switch, turning off the light. When level is below the pre-set limit, the dash light comes on. In later model cars, if the oil pressure drops, the switch turns off the fuel pump, to stop the engine and limit damage to internal parts. Oil pressure switches can be grouped into two categories, units for electrical gauges and for mechanical gauges.

Oil pressure can be checked at the sending unit passage with an externally mounted mechanical oil pressure gauge. To get accurate results from the test, make sure you follow the manufacturer's recommendations and compare your findings to specifications.
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 disconnected from the sending unit with the key switch on, the needle on the oil pressure gauge should be either all the way high or all the way low. Grounding the wire should make the needle move to the opposite side of the gauge from where it was before the wire was grounded. If the vehicle is equipped with an oil pressure light, touching the wire to ground and then removing the wire from ground should turn the light on and off.
• 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.

An oil pressure sending unit is removed with a special socket. Courtesy of Chrysler Corporation.

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

Measuring oil pressure. Reprinted with permission.

• 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.
  • Watch as the engine warms to note any excessive drops due to temperature.
  • Make sure the engine speed is set to specifications for testing pressure.
  • 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.
  • If the oil pressure is within specifications, this shows that the oil pressure sending unit may not be working correctly.
  • 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.