Hey guys, brand new here but pretty sure I’m in the right place. I have a 1993 22re with 199k that started to show high oil pressure off and on, and seemed to make some noise (sort of knocky) if there wasn’t a load on the engine and the truck was coasting. Initially I thought I had spun a rod bearing, so I pulled the engine. But after inspection, all of the rod bearings seem to be in pretty good condition so I don’t think that is the issue. Previously to all of this happening though, I had my timing chain guides re done, and when I pulled the engine and the oil pan off, I found a bunch of plastic down in the sump blocking a lot of the pick up tube screen:/ ...Id imagine this could cause higher oil pressure thus resulting in the noise from a lack of oil getting pushed though? But I would hate to just assume that is the case, put it all back together, only to find out that wasn’t the problem. Because it’s already out I’m doing rod and main bearings anyways. I’m also thinking it could possibly be a worn wrist pin? Is there a good way to diagnose a worn wrist pin without pulling the head? But I’m not sure why that would cause the oil pressure to go up sometimes. I suppose it could also be a bad oil pressure sensor? So, that being said, I’m just looking for a bit of advice on where to go from here from people that know more than me! (I’m pretty new to this stuff) Thanks!

 

1: bearings and clearences are either in spec or not, there is no "seems to be". You need to measure them a visual inspection is a waste of time and effort.

2: cloging the oil-pump pickup is not going to cause higher oil pressure. What it does is starve/restrict the oil volume at the pump's input. You have maybe heard of this " oil starvation " in cases of high G-force sustained cornering or prolonged off camber 4-wheeling?

3: you pulled the engine (that's by the book 17 hours of labor), by the way you could have just dropped the cross-member or front diff and gained access to those bearings, and now you're going to guess at whether the crankshaft and the block journals are still round without pulling the head off and inspecting the pistons or the cylinders or wrist pins just to save $30-50 on a new head gasket..

...
What you should have done is put a quantifiable oil pressure gauge on it in place of the dummy light or or guage sender while it was still in the vehicle so you had actual numbers of what the oil pressure was during operation. Why? Because this engine is engineered to have a wide WIDE band of oil pressure with its low-end tolerance enough to scare the pants off a typical "muscle head v8 owner" (like from memory single digit psi at idle, rangine up to 40+ and speed..)

Ok so there is this thing in your oil pump called an oil bypass, when this valve sees too much pressure from the oil filter it opens and feeds unfiltered oil.to the bearings. In the upside you engine doesn't seize because it's not receiving oil, the down side is if your oil isn't pristine and fresh there are particles in it that destroy bearings and bearing surfaces..


Bottom line don't short change your Toyota, fix it and fix it right. Doing anything less is short changing yourself and will only come back to bite you later.

You've kind of shot yourself in the foot by not identifying where the noise originated (with your stethoscope) before you pulled the engine, so just pull the head off and inspect the short block parts like the FSM instructions say.

 

There’s a lot to be said for taking compression readings, a leak down test, and getting a true oil pressure reading before a tear down.

 

Great post, but there are some misconceptions about the design and function of the two different oil pressure reliefs.

When the oil pump relief opens, the excess oil is dumped thru a port in the oil pump, thru a hole in the timing cover, then back into the sump.

The only time unfiltered oil might be delivered to the running engine is if the oil filter is completely blocked and the oil filters own internal relief opens because of excess pressure differential there.

The two different relief schemes operate completely independent of one another.