jviers

Greetings -

I have a 1992 4Runner with a partially/maybe crapped-out 3VZE. I bought the truck cheap knowing the engine had a loud knock. It came from a guy who had owned it for a month and decided he did not have time to fool with it. Besides the knock (!) the truck is in very good shape, body straight, paint
good, interior excellent, new clutch, new tires, CD changer, 5 spd (with 4.30 gears), no undercarriage dents, no wrecks, AZ vehicle, 152k. I have
receipts for about $2500 of stuff (tires, clutch, ball joints, idler arm, brakes, main seal, more). And besides the knock it runs really well, no smoke, no sooty or oily exhaust, clean spark plugs (a small bit of oil fouling on #6), very smooth idle, no other strange or unusual noises. The truck was driven knocking but as near as I can figure it was less than 10 miles.

Hoping that it was timing belt related I unfortunately found that the #2 rod bearings were pretty well beaten flat and partially broken (bits in the
oil pan) and had rotated around the journal. Before taking the cap off I could move the rod in and out a bit--clearly the source of the knock. I pulled
the other caps and the bearings all look good (as far as I know, I can take pics). I don't know the history of the engine as it was apparently replaced
not long ago (wrecking yard numbers, oil pan was off). I suspect the knock occured soon after major work was done and the owner, in the Army, was
transferred and simply gave up on the truck.

I have never really delved into bottom ends so I have to figure out what to do with this. The obvious answer is to swap for a 3.4 but that must wait a
bit. I would like to fix this so I can drive it (at least long enough to go pick up a 3.4!).

I guess my question for the experts here is how much effort is this 3VZE worth. A mechanic friend suggested just replacing the #2 rod bearings and
driving it until it dies. My current thought is to replace all rod bearings (#2 may have to be oversize), relatively cheap, and be done with it. As I
understand it the bearings can be replaced from underneath without pulling the heads (I want to avoid this). The head gaskets were replaced at some
point, and the timing belt (but it could use another, especially since I have the front torn apart). As to why the #2 failed and the other bearings
look good...? The crank journal oil hole drips oil so I don't think it is plugged (restricted?...but it drips as much as the others). Perhaps bearings
were installed incorrectly? #2 a problem area? I have not checked rod end-play.

Any and all help is much appreciated! Thanks; cheers, Joel

1styota4X4

I am right there with you I have a 95 with about 50K on the motor and the #2 crapped out I have been driving it for about 2000 miles and the noise stays the name no real change but when i undo the #2 plug wire it goes away. I found a low milage truck that I picked up for a grand and I am gonna strip it and part it out...

If you can fix the bearing issue cheap go that route and you will probably get some miles out of it that might buy you enoug time to save up for the 3.4 toyota motor swap

Cyberman

You can't fix a spun bearing by just replacing the bearings. Take it from someone who had that experience. I ended up pulling the engine, pulling the heads, removing the crank from the block, getting it machined and put new rod and crank bearings in. Granted, I did all the labor except the machining of the crank. Cost me around $350 when I was done (including head gaskets and head bolts).

jviers

Thanks guys!

Yeah, I was afraid of that. I don't think it spun "much" but I did find the bearing halfs sandwiched together on top of the journal. To my un-expert eye #2 surfaces don't look that bad (still completely smooth to the finger and no signs of overheating (and same light-ish color as other caps)) but I know "not bad" isn't really good enough. I think I have determined I cannot easily fix mine and I may go ahead and put a new rod bearing set on #2 just so I can move the truck around the driveway (knowing it will not last). I have measured the journal diameter at 0.14mm smaller than the #1 journal (not bad but I don't know roundness), and plastigage indicates 0.076 bearing clearance (FSM max is 0.080) so I assume I will need a slightly oversize bearing (torquing to specs left a slight wiggle in the rod assembly). But I pretty much know nothing about this...

I will now start looking for a decent used 3.4. As I understand it, for only a little more $s and comparable labor (to installing another used 3.0 or rebuilding mine), I can get a 3.4 in. I may be wrong but that is for another post. Others on other forums have suggested simply getting another used 3.0 but they seem in short supply here (if I was willing to drive to Phoenix I would have better luck), they are costing as much--or more--than a used 3.4, and I would then have an unknown engine with the same potential problems (and the few I have seen have very high miles).

Anyway, thanks for the reality check. Take care; cheers, Joel