Oil light coming on - WHY? 4AGTE/AE71

[maxhag]

Hey guys,
As some would know, I have just finished converting a AE71 wagon to a 4AGTE. The running gear, is a complete setup out of my crashed gold AE86... (proven motor setup, has run for 6 years)

I have only had the car runnng for a couple of days now, but I am getting the stock AE71 dash oil light coming on dull lit, and then it gets brighter as it revs, but never gets to full brightness.....
There are no oil leaks, I have changed the filter, checked the oil pressure sender isn't screwed in too far on the T piece, checked oil cooler lines arn't kinked. There are NO engine noises or rattles....
Engine has new Royal Purple 10w-40w oil, so the oil is top quality......

If I cruise along at 2500-3000rpm, the light will fade on and off as it pleases....

So, I am not sure if this is an electrical fault or if I am actually got low oil pressure..... ( I am pretty shit at electrical diagnostics )
When I turn the key to ignition (but not starting it), the lights should light up, yeah? , but they dont. ???? Only the charge light....

I thought that dash oil light was an either ON or OFF thing. Yay or Ney?
It's coming on very dull and gets brighter depending on revs....... The motor is getting tuned later today with a differant turbo than before (running a GT28R now), so because it hasn't been tuned yet, I havent revv'ed it past 4500rpm..... Since it's getting tuned on the Dyno this arvo, I want to be sure I am not having oil pressure issues before we put it on the dyno......

Any ideas?

JoJo

[jakel]

I would see if anyone you know has a oil pressure tester, remove the factory one and screw in the tester (the one we have at work is just an analog gauge with hose to go in where sender goes, run it and see if oil pressure is correct for your engine. My landcruiser has factory oil pressure gauge and was showing pretty much no oil pressure at idle but checked with gauge and has a fault somewhere not worried about it really because I know the pressure is fine.

But I would say it is an electrical problem.

[Matt]

That behaviour is pretty normal if you have the wrong oil pressure sender attached to the block... In the ae86 bigports, ae92 small ports the guage was actually a gauge and showed the variable oil pressure reading... In the ae82 bigports , 4afe , 7afe 20v's etc it was only an on / off light so you either had oil pressure by no light on the dash or not.

If you hook up the oil pressure sender to the on / off light you will have the symptoms that you are experiencing. As you start to rev the car, the oil pressure increases therefore causing the light to come on. The more you rev it the brighter the light becomes. If you swap the sender with an on / off one then it'll work as expected.

Most toyota engines share the same oil pressure switch , I have never used a universal one from supercheap etc. but there is no reason why i don't see swapping it out with one of those wouldn't work. Another option is to fit an after market gauge and keep the sender connected.

The easiest way to tell if you have the guage sender sized one is the size of the thing, if it has a bell on the top then it is the gauge style, if it is not much bigger than the thread itself than it is the on / off light.

Hope that makes sense.

[blinded]

Exactly that. Had the same issue when I first did my 4A conversion in my KE70.

I got a 4AC oil pressure SWITCH from the wreckers and it solved the issue.

[meadan]

Yeah the ae71s used an oil pressure switch, not so much a sender.

I would just get rid of the stock one and put in an aftermarket oil pressure gauge.

[Sam-Q]

Everyone above is right, if want to keep it all stock then swap it otherwise Meadan has sound advice because the factory oil pressure switch comes on at such a low point it's almost a "engine rooted" light

[maxhag]

Cheers guys........ Makes sense what Matt said, as the motor is a smallport AE101 4AGZE......

I have both sensor types here, I just never knew the differance in them... Makes sense, as the last 20V->KE70 conversion I did for someone did this same thing....

I have both sensor types somewhere around the place.....

I was planning to buy a pressure gauge next week, I was just concerned about the dyno...

Sweet, FULL STEAM AHEAD on the dyno this arvo!