I've got a '92 pickup. 22-RE 4wd model I know that this is a common problem and according to some of the comments below the video in the link it might even be original, but it's driving me crazy. I'm considering performing a full rebuild next summer, including installing a new oil pump, just as my comment said. Does anyone have any input as to what to do to raise it? Or if I should do nothing at all?

 

I assume this is NOT a video of your truck, correct?

Do you know what the actual oil pressure is?

The oil pressure gauges in these trucks are generally not very accurate. My gauge only reads to the first line on the highway and down to zero at idle. If the gauge was accurate, my engine would have been history long ago.

Is there any problems with the engine?

I would rent or buy a manual oil pressure gauge and hook it up to where the oil pressure sender goes. The reading should be much more accurate than the factory gauge.
I would definitely confirm your suspicions before throwing parts at the engine.

IF the oil pressure is low, your bearings are the most likely cause. It is rare that an oil pump causes low pressure as a pump creates volume of flow, not pressure. The rod and crank bearings create resistance to flow and when they wear out, you lose pressure. Usually the rest of the engine is worn out at that point.

 

Before you rip the engine apart make sure you verify that your oil pressure sending unit is workin

 

No, it's not my truck and I have considered taking a look at the actual pressure using a numbered gauge but I haven't had time to take a closer look under the hood and look for a place to hook up a gauge. Tomorrow I'll look into checking at the oil pressure sender. The reason I suspect the oil pump is this truck sat for maybe 5 or so years and I wonder if the pump is plugged up with something. Yes, we did a relatively thorough tune-up since then.

 

I'd bet you $100 that both your oil pump and oil pressure are fine. Those gauges concern all of us until we accept the fact that the vast majority of them read just like yours. I know mine does. The little mechanism inside your sender has been in there for ever and has a ton of buildup on it. It probably doesn't move in and out like it used to. You did say that the gauge falls very slowly when you go back to idle. If you are thinking about plumbing a gauge into that same port, I would just go ahead and replace the sender. I bet that's all you are going to need to do. Be careful though. I have heard of several senders that were seized up in there really bad and my buddy, who has been a high level mechanic for years, had his break off and had a terrible time getting his out after it broke off.
I would have already changed mine if it weren't for the trouble he had with his.

 

For this very reason I run manual oil pressure gauges in my Toyota`s

Know that these engines the oil pressure varies quite a bit as the rpm changes

At idle no lower then 5 psi at 3000 rpm anywhere from 36 to 70 psi at operating temperature

 

I forgot to mention that cylinder three has low compression and that she burns a little oil and blows blue smoke sometimes on start-up. Obviously oil. So we have assumed that we've got bad valve guides on that cylinder. Repair/replace is part of the goal of the upcoming summer rebuild.

 

Installed a rebuilt engine at 328,000 due to mechanic letting anti-freeze into the oil pan and ate the crank bearings. He put in an aftermarket oil pressure sending unit. It always read low where idle was near bottom mark and interstate driving was just above the 2 mark. The original OEM one read between the 2 and 3 all the time. Had the pressure checked and it was good. Finally got tired of it and bought a OEM Toyota one ~$70 and it now reads like new.

Could be your sender is bad and put in an OEM Toyota one. More money, but if you're going to keep it, then a good oil pressure reading is peace of mind.

 

Wow! That is a huge swing. My Chevy work truck has a digital reading and it never goes below 30 and never above 55.

Our factory gauges sure make a lot of folks nervous. That's probably why they did away with them in later generations. I know a Ford master mechanic and he told me that on one particular model, so many folks called in concerned about low idle oil pressure, that Ford actually modified the gauge to read at the lower of the two middle marks no matter how low the pressure dropped. So the gauge's travel was only between the two middle marks while the engine was running. It would fall to zero, of course, when you shut it down as not to arise suspicion.

 

Sounds right on as the 1986 Toyota orange shop manual states at operating temp at idle it's 4.3 PSI and at 3000 rpm it's 36 to 71 PSI.