Location of oil pressure sending unit on 3 8 engine, on an 1986 Oldsmobile brougham? Also I am replacing the radiator which had a disconnected, what looked like a cooling sending unit located on the side of the radiator? Is this where the cooling unit sending unit is located? My cooling fan does not appear to be working properly, so I would like to know, if I can straight wire the fan motor with a toggle switch, by bypassing the relay? I am attempting to install a set of gauges mounting inside my car instead of those idiot lights.

It is located on rear of engine back by the distributor use to be. see attached pic

you will have several sending units.
1. Oil pressure sending unit, which according to peoples site that I have visited is right above the oil filter.
2.sending unit in gas tank going to gauges, which is in the gas tank.
3. temperature sending unit, which is located near the thermostat housing or near the end of the upper radiator hose.

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.

might need a new speedometer

2.2L ENGINE OIL SENDING UNIT LOCATED FRONT CAMSHAFT HOUSING ON LEFT DRIVER SIDE OF ENGINE.FOR 3.1L ENGINE OIL PRESSURE SENDING UNIT LOCATED NEXT TO OIL FILTER.

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).

try replacing the oil sending unit, it is located at the back of the intake. it is about two inches long. it is black. it ties into the fuel injection system.hope this helps.

GM Bonneville/Eighty Eight/LeSabre 1986-1999

Oil Pressure Sender

OPERATION
The oil pressure sender/switch relays the engine oil pressure to the dash gauge.

TESTING

1. To test the normally closed oil pressure lamp circuit, disengage the locking connector and measure the resistance between the switch terminal (terminal for the wire to the warning lamp) and the metal housing. The ohmmeter should read 0 ohms.
2. To test the sending unit, measure the resistance between the sending unit terminal and the metal housing. The ohmmeter should read an open circuit (infinite resistance).
3. Start the engine.
4. Once again, test each terminal against the metal housing:
   1. The oil switch terminal-to-housing circuit should read an open circuit if there is oil pressure present.
   2. The sending unit-to-housing circuit should read between 15-80 ohms, depending on the engine speed, oil temperature and oil viscosity.
      
   
   
5. To test the oil pressure sender only, rev the engine and watch the ohms reading, which should fluctuate slightly (within the range of 15-80 ohms) as rpm increases.
6. If the above results were not obtained, replace the sending unit/switch with a new one.
   

REMOVAL & INSTALLATION(see Figure 1)

1. Disconnect the negative battery cable.
2. If necessary for access, raise and safely support the vehicle.
3. If necessary, drain the engine oil into a suitable container.
4. Detach the switch electrical connector.
5. Remove the switch.

Fig. 1: Location of the oil pressure switch - 1995 vehicle shown, others similar

To install:

1. Coat the first two or three threads with sealer. Install the switch and tighten until snug. Engage the electrical lead.
2. Carefully lower the vehicle.
3. Fill the crankcase with the proper type and amount of engine oil.
4. Connect the negative battery cable.

Hope helps with this (remember rated this help) Good luck.

On all 2.0L and 2.4L engines, the oil pressure sending unit switch is located on the engine block, below the exhaust manifold, on the firewall side. On all 2.5L engines, the oil pressure sending unit switch is located on the engine block, below the front exhaust manifold on the radiator side.

I JUST SPENT A WEEKEND SOLVING THE ISSUES THAT SEEM TO BE THE SAME AS YOURS. FIRST THE PROCESS OF THIS MODEL IS THAT WHEN THE KEY IS PUT IN THE RUN POSITION, THE FUEL PUMPS ACTIVATE AND ONLY FILL UP THEMSELVES. WHEN THE TRUCK ENGINE IS CRANKED, THE OIL PRESSURE ACTIVATES THE SENDING UNIT AND IT ACTUALLY TELLS THE FUEL PUMPS TO KEEP PUMPING WHILE THE ENGINE KEEPS TURNING OR RUNNING. IT IS A SAFETY ISSUE, AS IN A WRECK, THE ENGINE DIES, AND THEREFORE THE FUEL TO THE ENGINE IS STOPPED, AS A FIX, TRY PRIMING THE CARB, AND SEE IF IT RUNS BRIEFLY. YOU WILL ELIMINATE ALOT OF EXTERRANEOUS ELECTRICAL ISSUES IF IT RUNS. NEXT, CHECK CONTINUITY AT THE FUEL PUMP RELAY. IT IS LOCATED UNDER A PLASTIC COVER ON THE FIREWALL TO THE RIGHT OF THE BRAKE BOOSTER PUMP. MINE HAS 5 WIRES GOING TO IT. I HAD TO UNSCREW THE COVER TO ACCESS THE HIDDEN SNAP THAT HOLDS IT IN PLACE. HAVE SOMEONE CRANK THE ENGINE AND FEEL IF THE RELAY ENERGIZES. IF IT DOESN'T, AND THIS IS WHAT WAS WRONG WITH MINE, YOU WILL NEED TO FIND AND REPLACE THE OIL PRESSURE SENDING UNIT WITH 2 WIRES. THERE ARE 2 WIRES THAT WILL LEAD YOU TO THE OIL PRESSURE SENDING UNIT FROM THE RELAY. THERE ARE 2 SENDING UNITS AND THEY ARE LOCATED AT THE REAR OF THE EXHAUST MANIFOLD, BEHIND THE CARB. THERE IS A BIG ONE, WITH ONE WIRE, WHICH IS THE OIL PRESSURE SENDING UNIT FOR THE GUAGES, BUT BELOW THAT IS ANOTHER SMALLER SENDING UNIT THAT HAS 2 WIRES GOING TO IT. IT CLOSES WHEN THE ENGINE TURNS OVER AND ACTUALLY TELLS THE FUEL PUMPS TO KEEP PUMPING GAS. SEE IF THIS WORKS. THE FUEL PUMP RELAY WAS 15 DOLLARS AND THE OIL SENDING UNIT WAS 16. SPENDING ALL WEEKEND WITH THE WIRING SCHEMATICS AND TRACING ALL OF THAT STUFF-----------PRICELESS.