Did a search on this and i am getting mixed feedback.

I hope i can explain what i currently am going through and see if people had this before. its a 2004 4th Gen 4runner

I was on a upwards tilt coming out of a garage. oil light started flickering very dim, flickering like its flashing really fast on a dim scale.

Went on level plane and it went off.

Came back on after 2 miles now stronger lit, it goes off, comes back on.

I take it home, and i read on the forums to check the oil filter.

Changed the oil filter, changed Oil,

i took apart the old oil filter to inspect if it fell apart and its lodged somewhere in the motor. The oil filter is fine.

inspecting the old oil, Oil was dark and was on 4k miles on full Mobil 1 gold cap.

Started it back up, oil light is still flickering, Valves have no sound but i dont know if its my imagination but there is a small hissing sound when you rev. Like a turbo spooling.

Does anyone know what is going on?

Some said i have to drop the oil pan and inspect to see if its clogged, some said i might have to replace the oil pump.

What is the safest way to resolve this? The oil pan does not look like it will be an easy job, and god knows where the oil pump is.

Update, this test might be nothing but just wanted to note.

i disconnected the oil sending unit wire going into the plug right next to oil filter.

started the truck with it disconnected and the light is still flickering.

Could this mean its electrical?

I am going to clean the sensor connector and plug it back in.

What should happen if i disconnected that sensor and started the car? should the light be off or on?

Hope someone can help!

What engine do you have? Are you sure you disconnected the oil sending unit and not something else?

Thanks for the response.

I have a 4.7 2uz

Yes, its right next to the oil filter, practically connects to the filter house that the filter screws into. it defintely is the sending unit.

i went further and grounded the wire, it made a constant light now, not a flickering. if disconnected entirely, it flickers. if its connected it flickers.

This has me all confused.

How many miles and how long have you owned this T4R? I bought my T4R #2 with the same problem. The first owner leased it and at 89,000 the dealer sold it without changing the timing belt. During the lease no oil changes listed by the dealer or car fax. The second owner drove it to 154,000. That's when I got her. The engine was oil sludged.
The 4.7 only has 5 psi oil pressure at idle. After you have ruled out the sending unit drop the oil pickup pan. It is the small steel pan where the oil drain plug is located. See how much sludge is in the pan and if the oil pickup screen is open.
The oil pump is gear driven and is located at the front if the engine behind the harmonic balancer.

Is there a plug or port somewhere (possibly same one for sending unit) that you can add a mechanical gauge ? I would want to know if there is sufficient oil pressure or not.

On the flickering, sounds like there is a shorted wire somewhere. Any signs of mice or squirrels in the engine compartment?

i have changed the sensor and the oil light is still flickering, and its a little more accurate to RPMs, the flicker turns brigher at lower rpm, and gets dim at higher RPM. before sensor was replaced i tested the wire by grounding it...no problems with the wire.

This is after i changed the sensor and the oil to 20w-50.

Question, where can i get a oil pressure gauge that will fit the 2uz v8?

How often does the oil pump go bad? with my 170k miles, maybe its time to replace?

also, if i have to change the oil pump, do i have to drop the oil pan?

If i have to drop the oil pan, can all this be done with the motor in the car. the manual says i have to pull the motor. JESUS its the AWD version and theres a lot under there right below the pan.

My goodness i hope you guys can help with this info.

Holy crap dude, what the hell are your running a 50 weight oil for?

You are destroying your engine. It's clear as day its either oil sludged beyond repair, or more likely the pump. Throwing 50 weight is not a good idea. You might get the psi up, but your starving your engine. Your going to throw a main bearing or seize piston.

damn, a shop told me to run heavier oil to see if it changes the light.

will be changing it again. my ol my

I agree. I think 20W 50 is a bad idea ESPECIALY if it gets cold. Why not the recommended 5W 30?

That is horrible advise, according to Toyota 5W-30 should work fine into the -24~24*F range as per the owner's manual.

The reason it is probably flickering/changing with RPM is that the engine is experiencing oil pressure issues trying to shove 50 weight oil through places designed for 30 weight. I'm surprised you haven't set VVTi codes or had issues with the engine running since that will affect performance some.

Also, you said a shop recommended you run a heavier oil to see if the light changes? So this issue was prior to you putting 20w-50 in the vehicle? Have you had a shop do a oil pressure test on the vehicle with 5W-30 in it?

well good news?

i wanted to do this right. i got a oil pressure gauge to see the pressure before i start going bonkers with the oil pan and what nots.

so the verdict is....

i have around 26-30psi at idle, fully warm with 5w-30 conventional oil
80 psi at 3k rpms.

i really don't think theres a problem here. motor runs great, pressure seems fine.

Not sure what the official Toyota specs are but I would guess that is plenty of pressure. I've always heard from old skool engine builders, at least 5 psi for every thousand rpm.

WOW

Totally forgot to update this.

if you are having the same issue and see a flicker it was the wire for me. it was the wire harness that was rubbing on one of the belt drives. it was grounding to it.

Please check all ELECTRICAL connections before assuming the worst like me!