Motor oil pressure light - 2001 Mazda MPV

Oil light is rather important it goes out if oil pressure is good comes on if oil pressure is low when it comes on damage is expected with continued operation like wearing of main bearings and pistons and cylinders can lead to a engine rebuild

a 2004 toyota highlander V6

this should be your engine type
The 2GR-FE is a 3.5 L (3456 cc)

if leaks are that bad
always check the engine oil level before you drive off

fixing oil leaks on motors
degrease whole motor top and bottom

start with replacing the oil sender it may be the cause of the oil light coming on
after degrease
lay cardboard or paper under the car
take out for a drive and park over the paper over night

this pin points most of the oil leak locations
leaks from a V6 motor
rocker covers/ spark plug tube 0 rings.engine seals
cam seals
front and rear engine seals leak often
sump gasket can leak

if oil consumption or light on continues
can be a failing engine oil pump
or worn main bearings giving low oil pressure to the whole engine
you could be burning oil from worn piston rings
or hardened valve stems

a mechanic can fit an oil pressure gauge to the motor when hot
to check running oil pressure to confirm low oil pressure

if engine is worn out

it is possible to fit a lower mileage used motor to your highlander
its often cheaper than and engine rebuild

Good Day

Firstly check your all Oil pressure switches if they are not faulty.
Remove your electrical oil pressure switch and fit a mechanical oil pressure switch and start the motor:Oil Pressure reading should be between 4-8 bar on the gauge.
Motor must be at working temperature.
If Oil Pressure is below 4 bar their could be a problem on your crankshaft.Depending on milage.
Your Big end and Main bearings determine your oil pressure.
If the engine milage is high this can cause oil pressure fluctuation as their is wear on the bearings.

Regards
Martin

Possible causes
- Low oil level or motor mechanical fault
- Faulty oil pressure sensor
- Oil Pressure Sensor harness is open or shorted
- Oil Pressure Sensor circuit poor electrical connection

When is the code detected?
The P0521 is detected when the signal sent from oil pressure sensor to PCM goes out of range.
Possible symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
- Oil pressure warning light ON.
P0521 Chevrolet Description
The PCM continuously monitors the engine oil pressure. The Oil Pressure Sensor/Switch sends a signal to the PCM when the engine is running.

Check the oil pressure with a mechanical gauge, I think you have a low oil pressure

First, do not keep driving if the oil warning light is on or your oil pressure gauge has dropped. Stop the engine, let it sit for a few minutes, then check the oil level.
If the dipstick shows a full oil level, then low oil obviously isn't your problem. The oil pressure may be low because of a worn or broken oil pump, a plugged oil pickup screen in the engine's crankcase, possibly a plugged oil filter or excessive bearing wear. Or, the oil pressure may be fine but the oil pressure sending unit has failed. Further diagnosis will be required to determine what's wrong.
Perform electrical tests on oil pressure switch http://www.clarks-garage.com/shop-manual/elect-19.htm
Replace pressure switch as the cheapest means of repair to see if the lights go out .
The pressure switch will be located on the engine block.

Change your oil pressure sender. The oil pressure sender will usually break before the oil pump will. If you are driving with the oil light on and the motor has not seized the oil pump is probably all right.When your oil light comes on you need to turn your car off immediately so you do not damage your engine crankshaft and camshaft bearings. If you change the oil pressure sender and the oil light stays on then you should replace your oil pump before more serious damage happens to the motor.

if its not low oil then i would suspect a faulty oil pump

the oil sending unit is bad

If the oil light is on, Don't drive your car until you've checked the oil level .
The oil light is an indicator that warns you when the oil level has dropped to an unsafe level and will not allow proper oil flow thru the motor because the oil pressure is dropping.

Don't take a chance! Check the oil level. Make sure it's between the full and add 1 quart line. If you don't see anything on the dipstick, it's really low... If you run your car with low oil, you're going to freeze up the motor.

If the oil level is ok and the oil light is still on, have the pressure sender checked to make sure there's proper oil pressure. The light will stay on if there's a problem..