Low RPM + Oil Light

You only get low oil pressure light due to low level when the o-rings on the dual pan had failed and pump is sucking air. Otherwise that light will not come on until you are completely out of oil.

 

Oil levels were good. Lower end of the middle of the two dots but good. Ill add a bit more to see what that does but Im guessing bad switch.

 

My 84 Camry, when almost new and with 5,000 KM's on it, would flash the oil light, when full of oil, if the RPM went below about 600 RPM. It would also do it when stopping quickly like at a traffic light. The dealer at one point (it took 4 trips to the dealer to fix this) bumped my idle to 1100, from a normal around 650/700. But, I sat in the parking lot, put the emergency brake on, ran the idle down to under 600 RPM, using first gear and the clutch, and bingo, the oil light came on. I went back in and asked them to "fix" it.

The oil light is there as a safety feature, on older cars it it triggered by low oil pressure(not sure about "new" stuff). I've never seen an engine which has an "oil gauge" like a fuel gauge, measuring how much oil is in the engine.
Low oil pressure will occur when oil is low, common sense says this should be triggered before you are completely out of oil and your engine seizes.

If new engines have something different for turning on the oil pressure idiot light, I'd be curious to know what that is.

To the OP, it doesn't appear to be low oil that is causing your problem. So a sensor or the oil pump itself, or something blocking the intake for the oil pump?

Don

 

4.3psi/700rpm+50 @operating temp is minimum from the FSM. I don't just make this shit up.

I put the specs up because it shows that the pressure switch must make at some point at or under 4.3psi and that's pretty low. Just the difference in atmospheric pressure between 0 and 9000 feet is 4.2psi. "Mod" seems to see the significance.
Obviously checking the pressure should be the first step on such a life and death issue because "It's hard tellen, not knowin".
In the end it is entirely possible that low idle speed, for what ever reason, could trigger the switch.

 

I might be stupid. I did a oil filter relocation. Im going to check for kinks in the hoses I ran. If that's not it, back to square one.

I ordered a new switch anyways (Amazon had best price btw)

$42 Genuine Oil Pressure Sensor/Sending Unit 83530-0E010

http://www.amazon.com/gp/product/B00GJJDQBG/ref=od_aui_detailpages00?ie=UTF8&psc=1

 

Nope.
Oil pressure has very little to do with level. Oil pump sump seats at the bottom of oil pan. You would have to be out of most oil for that pump to start sucking air instead of oil.
Now here are the cases when oil level can affect pressure
1. Rubber seal on oil pump had failed - and because its easier to suck air than oil pump will get more air into the system depending on how high oil level is (the higher the level the easier for pump to grab oil)

2. Rubber O-ring between pump and top Oil pan had failed (one for sump) and you sucking air like in the case of the seal on pump. Same story with the level.

3. Rubber O-ring between top pan and lower pan failed (one for sump) and your level is so low that air can be sucked through there.

4. Your sump screen is so clogged that air can be sucked through any of the above seals due to massive vacuum and your level is low enough to expose all 3 seals.

Otherwise level has nothing to do with pressure. All above are failures that needs fixing.
I had all 3 in few of my cars. The only one that is visible is the seal on oil pump because when truck is parked usually you can see a leak.
Others you only figure out by dropping oil pan or measuring pressure.

 

By all means check that out but a restriction in your remote filter system should increase the pressure seen by the pressure switch while starving the vital engine parts. That's one of the reasons I decided against a remote.
This is based on this diagram (Toyota document) and my assumption that the switch is between the pump and the filter.

 

Your idle, in gear, is too low. I'd check/clean throttle body, and as was mentioned before, the MAF sensor as well.
Older vehicle or newer, the idiot light comes on when pressure drops regardless of oil level. Oil pump is engine driven. If it's not pumping at it's minimum rate or better you will get a low oil pressure situation.
Oil pumps are very basic in design and function. it's rare, not impossible, but rare to have one fail.

 

I think you are right, Ill go back to my original hypothesis and look at my idle functions.

Im going to hook up my computer to the FIC and get a better idea of what is going on.

 

Not at all. the only stupid question dealing with something especially like this, is the one that didn't get answered or asked. Make sure it is a smooth path thru that stuff. Jeg's branded parts can be questionable. I think it's a Jegs relocator? yes?

System 1 has really nice product. Fuel filters and oil strainer filter setups, all kind of cool gizmos for that stuff, relocators, ect. Spendy,,but proven. You have some money in your truck,,so make sure all is well all the time.

Oil pan work recently I see. Same pan went back on? The oil pump pickup bolts were never touched? yes?.

 

I think at 500 RPM, you should still have enough oil pressure so the oil light does not come on.

Low oil will cause the oil light to come on, if its really low and say you are stopping quickly, the oil will be not making contact with the oil pickup. My old 6 cyl Chevy would burn a quart to 500 miles, the oil light would flash when stopping quickly once it was down about 1 1/2-2 quarts. Fill it up and no light until it was low again.

Don

 

Still no luck. Im guessing the oil reliefe valve is stuck open. Anyone know where this is on the 5VZ and how to replace it?

 

What is your exact idle RPM and oil pressure. Until you have this info you are just guessing.

The general location of the PRV can be seen in the diagram in post 28.
To access it merely drop your skids, front diff and oil pan. It's right there. Pretty big guess.

 

Fuck, please don't tell me I have to drop the pan...

I thought you could access it behind the timing pulley

 

Yes, merely drop your front diff, have fun!

 

I've already done it twice... Not fun.

 

Yup, I'd rather get water boarded.

 

Accurate idle speed and oil pressure?

 

Idle speed is at 580 when the light starts to flicker and at ~550 when the light comes on solid...

 

Fixed the light! I guess there's still a vacum leak from my PCV valve. When I disconnected the catch can from the manifold, the oil light stopped coming on. Oddly enough, the RPM's are now reading lower