22r low oil pressure when warm

[Eugene13]

I have been having this problem for about 6 months now, but fixed it (or so I thought) about 3 months ago. SO the problem is I will drive my truck and as it gets to operating temperature, I can see the oil light (not a gauge) start to flicker on and off. The more I drive it the more it stops flickering and stays more solid. The is only at idle however, not while driving, and I can blip the throttle and the light will go off. I was assuming this was cause of the viscosity of the oil being too thin, so about 3 months ago I changed the oil to 20w-50 and that fixed the oil light. Well now this light come back on but I have not changed the oil. Any ideas what's happening? Do a need a better quality oil that won't degrade as fast? Sensor problem? Any help appreciated:couch2:

 

[Eugene13]

I have also noticed a slight loss in power overall when I'm driving around and have also lost some mpg:help:

 

[cap10]

What year ? How many miles?
If its a high mileage motor then you may have problems that cannot be fixed by changing oil.
If your motor is NOT a high mileage motor then it could be a number of minor things that could cause a oil light to come on when its not supposed to.

 

[Eugene13]

'84 22r with 211k

 

[ev13wt]

I suggest measuring the actual pressure, then new oil pump probably. Do chains when you are in there as well, and water pump

 

[Eugene13]

Did timing chain and water pump about 5 months ago but didn't replace the oil pump at the time cause it functioned fine before I put I took everything apart. Could that be the issue? if so is there another way to test it?

 

[old87yota]

I would check your actual oil pressure with a reliable mechanical gauge (you can usually borrow or buy from a local auto parts store) before doing anything else.

Oil pump failures are pretty uncommon as they are very simple mechanisms and are constantly bathed in oil. Usually the bearings in the engine will wear out well before the oil pump and the bearing clearances are a key factor in oil pressure.

As stated, there could be a number of possible issues, but you should collect some data before guessing what part to throw at the problem.

:fro:

 

[Eugene13]

Got it. I'll find out how to check pressure with a mechanical gauge. What numbers would I be looking for?

 

[old87yota]

I am not 100% sure what the 1984 specifications are (you most likely have the early 22R version), but I am willing to bet they are very similar to the late 22R specifications.

From my 1987 Factory Repair Manual:

1. Check Oil Quality

2. Check Oil Level

3. Remove Oil Pressure Switch or Sender Gauge

4. Install Oil Pressure Gauge

5. Start Engine

Start Engine and warm it up to normal operating temperature.


6. Measure Oil Pressure

At idle speed: More than 4.3 PSI
At 3,000 RPM: 36-71 PSI


Toyota gives a pretty large range for acceptable oil pressure.

I am pretty sure the oil pressure gauge needle should not bounce much on a healthy engine. A bouncing needle indicates momentary loss of oil pressure most likely caused by worn bearings in the engine.

:fro:

 

[Eugene13]

[MENTION=209393]old87yota[/MENTION] wow thanks for the detailed explanation! will probably get to it this weekend. if the bearings are the issue, I can replace them without taking the engine out right? I can just take the oil pan off and replace from the bottom.