ok guys. im new and looking for some help. my 87 4x4 toyota truck oil light comes on when i start. and stays on for like 20 seconds. and the light comes back on when i get into the high rpms of each gear. why is this happeneing?????

i have a 22r

 

Checked the oil level?? Sounds like it's low, when you get in the higher RPMS it's emptying the pan of oil faster than it can flow back down though the engine.

 

Any new noises to go with it?

How many miles on the engine?

Has the oil pump ever been changed?

How many miles on that oil?
What oil weight are you using?

 

Pump shot, return ports clogged, very low oil level, thin low viscosity oil

 

Check the oil level!!

Hope that is the problem.

The oil light should only be on before you crank the engine.

The next easy fix is the sending unit is not working correct.

wrong weight oil.

Then on to mechanical issues

worn engine bearings worn enough to increase clearances

oil not returning to the oil pan as it should.

these oil pumps are pretty good but they do wear out and lack of maintenance does not help.

 

Mine would come on when I let off throttle. It was low on oil. Hope that helps

 

If you're actually low enough on oil (or pressure) to make the low pressure light come on, you're not far from causing damage to bearings. However, it's more than likely either low pressure, or, you have a gauge sender instead of a light sender. On the block, just below the oil filter, is a wire connected to a plug bolted into the block. If your plug looks like a big brass can, it's for a switch, if it looks like a bolt with a connector, it's a light sender. If you have the right sender, it's time to hook up a pressure gauge and see what your oil pressure actually is.