Oil pressure light issues

99 Tacoma 2.7L 329k miles...unknow motor history before 300k miles.

So very randomely the oil pressure light will flicker, Not even fully illuminating just flicker

It's very spuratic and it only seems to happens under these condtions.

Running highway speeds for 20 mins or so...coming to a stop and taking off quickly say 50% throttle and only through first and second gear it may flicker very dimly.

Never at cruising speeds...very weird.

 

Have you checked the oil level???

 

Suggest take/get a real oil pressure reading. Possibly the oil pressure is borderline (low).

 

True. At that mileage the oil pump could have enough wear to cause low oil pressure at the lower engine speeds.

 

Oil level is good.

At idle oil pressure is sitting at 25lbs by the gauge I have.

 

Check the oil pressure sensor. Loose wire??

 

I didn't feel any loose wires or anything...didn't pull too hard.

Sensor is what 16 bucks...may try that.

 

So it did it a little more on the way home.

It only occurs while the engine is underload like taking off. Idling you can Rev it all day and nothing happens.

Also as soon as you back out of the throttle it stops...which is weird

 

So now when idling and Rev to 2k rpms and let off the throttle the ligh barely dims.

Could it be cluster related because the temp gauge doesn't work either.

 

well worn engine on its last legs showing intermittent L O W oil Pressure

not Unusual

 

In truth....if the easy things have been verified as correct......then that leaves the oil pump itself.

The behavior you describe is typical of a worn pump. In a nutshell, the oil will slip past the end gaps of the pump. I believe the oil pumps in these truck are the gearotor type. Normally, the oil is between the teeth of the pump. But when the pump becomes worn and the end gap becomes large, the oil will slip out from between the teeth. The issue is less pronounced at higher pump speed, ie engine speeds.

Check both pressure and flow at idle. Pressure alone is not enough.

 

Well after checking with a manual algae agin is still showing good oil pressure.

After removing the air I take I found the wiring harness that the temp gauge and oil pressure wires run through in rough shape..



After putting the sensor back in and re rapping the wire I drive thr truck on a 30 MI ite trip...not once did the light come on...and before this the day before is was coming on almost consistent to the point t engine should have had damage

Again checking the oil pressure with a gauge it's showing 30+ lbs.

If a oil pump was worn would it not continue ually get worse and not just get better fir a few days

 

If you go back to post #11... "...if the easy things have been verified as correct.."

Apparently, you had a wiring issue causing the intermittent warning light.

Yes, the oil pump is mechanical. Yes, it will wear and continually get worse. But the oil pump is one of the most robust parts on an engine. Your symptoms manifested when the engine went from high rpm to idle or stopping. Pump degradation is typically very slow.

There is a lesson here. Always check and verify the simple things first. Wires, filters, sensors, pressure, pump.......

Glad you found the problem and the fix was easy and simple.

 

Just to post my experience with the same symptoms.
Last winter (1 yr ago) I had the same happening with correct level of oil. I read a couple places on the net where others had oil pressure light illuminating at times and how this would happen with some brands of oil filters.
I had a cheap STP filter in at the time....changed oil and got oem filters from the dealership and never had it duplicate again. 98' Tacoma 2.7 with 284,000 miles on the odometer.