Turns out my 1994 4Runner has a bad rod bearing, among other things

[brocktice]

The place I had it inspected doesn't do rebuilds. They sent me to another place that does, but they made it sound like it would be over $3k, minimum, more to replace it with another engine.

I've seen people quoting sub-$2k rebuilds on here. Am I talking to the wrong people or am I missing something?

 

[KidVermicious]

Am I talking to the wrong people or am I missing something?

Well, both. Over $3000 sounds a little high to rebuild a motor, but even if that was a good price I wouldn't do it. I think if you're going to own one of these older trucks, you need to know how to work on them. An engine rebuild is a hell of a place to start, but you'll get the hang of it. The alternative is to make your mechanic a very rich man, or pitch the truck and buy something newer.

 

[brocktice]

I was thinking I might start with checking the rod bearings. It's pretty subtle at this point, maybe the damage isn't bad?

Honestly I like the idea of rebuilding it myself. I hate the idea of how much time it's going to take, as I've got a job and a couple other businesses (one of which I bought the 4runner for), and two kids taking up all the time I've got already. I used to work in a community bike co-op and rebuild old bicycles, I work on my guns a bit, I've built a couple of 3D printers, and I have a PhD in an engineering field (albeit not mechanical). I ought to be able to handle it and even enjoy it. It's just the time.

If I can find someone in Albuquerque (seems there are several there, all closed for the weekend) to rebuild it for under $2k with a warranty, I'll probably just do that. My budget for getting a vehicle for this project was about $5k max anyway. I need the vehicle and I need it running reliably sooner rather than later. If not, well, time to start taking it apart I guess.

I did notice that people offroading seem to be ready to do all kinds of stuff to repair damage from that activity, from cleaning out an engine filled with water to replacing axles in the field (!), so I agree it's probably a skillset I need to build.

 

[brocktice]

The strange thing is that I'm not seeing any other symptoms of a bad bearing, but maybe I've just not been driving it long enough to notice it burning oil. Temp looks fine. I'm not through a full tank of gas yet, but I'm at about 140 miles on half a tank, which is pretty good, right? Definitely need to investigate further. It was diagnosed by sound, they didn't drop the pan or anything.

 

[KidVermicious]

I was thinking I might start with checking the rod bearings. It's pretty subtle at this point, maybe the damage isn't bad?

You could definitely start with that. You'd need to drop the pan, and to do that you'll have to wrestle the front diff out. If you haven't done it before I'd call that an all-weekend job, the diff is a PITA. Which is probably why your mechanic didn't do it. I can't speak for the 3VZE, but on my 4cyl at least, once you get the pan off, checking the clearances on the rod bearings themselves is pretty straightforward stuff.

 

[brocktice]

Yeah I was aware of needing to drop the differential, found a good thread on here that details it. The good news is this car is not my daily driver, so I can afford to spread it out over a week if I need to.

EDIT: Hahaha, the good writeup is yours!

 

[brocktice]

You could definitely start with that. You'd need to drop the pan, and to do that you'll have to wrestle the front diff out.

I also need to replace one of the CV axles, seems like this would be a good time to do it. One thing that's not immediately clear to me -- can I do this on ramps? The wheels should still be secure, right? I'm only detaching drive components, right? Or do I need jack stands? I'd prefer the ramps if I can do that.

 

[KidVermicious]

I like to unbolt the upper ball joint to pull the CV shafts off the axle stubs, and even if you don't do that it's kinda hard to maneuver the CV shaft out of the spindle without jacking the a-arm to exactly the right angle.

I supposed once you've dropped the diff and yanked the axles, there's no reason you couldn't drive it onto a set of ramps though.

 

[brocktice]

I think if you're going to own one of these older trucks, you need to know how to work on them.

Discovered today the 4WD was not actually working, even though the mechanic supposedly confirmed it was. Figured out the vacuum hoses to the ADD were swapped, now it's fixed. I'm hooked!

 

[4runnerBrett]

I had same issue with mine we dropped the oil pan and threw in a new bearing and I got 9 more months out of it. It would of lasted longer but i found out the previous owner didnt have a rear main seal and so I went to mountain and I'm guessing oil poured out .

You have to pull front diff and all the front bars. You have to install the bearing and use a plastic gauge to find out the clearance and make sure its within tolerance then just use really thick oil.

Its kind if a temp fix but will buy you some time to save up for a motor.

 

[brocktice]

I did something today I should have done before. One of the two guys who looked at it helped me pinpoint the sound, and it seemed to be around the #2 cylinder. Today I tried pulling each spark plug from the distributor, starting it, revving it, listening, and then moving to the next plug. I could not produce any change in engine sound doing that (except running a bit rougher than with all six firing), at least not that I could detect. Makes me think maybe it's something in the valves after all. My valve cover gaskets are leaking anyway, so I picked up some new gaskets today and as soon as I get a chance I'll pop 'em off and take a look.

 

[4runnerBrett]

Get under the truck and listen by the oil pan. You will know if its a rod bearing .

 

[brocktice]

Get under the truck and listen by the oil pan. You will know if its a rod bearing .

I'll try tomorrow. I've watched more vids of people with rod knocks on YouTube (3VZ-E and other engines). I just cannot hear anything like it. I may have to try the tube to the ear trick and really listen closely. I can't shake it that two mechanics listened to it (the second one knew he was looking for rod knock) and heard it. I cannot.

 

[nicnmike]

Are you sure it isn't coming from the fuel pressure regulator? My engine ticks too and that's where it seems to be coming from on my mine.

 

[brocktice]

Are you sure it isn't coming from the fuel pressure regulator? My engine ticks too and that's where it seems to be coming from on my mine.

Not sure at all, any way to check?

EDIT: guess I need a hose or stethoscope

 

[brocktice]

Ugh now I hear it, all it took was putting my head down under the bumper once it was good and warm. And it is indeed bad. Good thing I have a hoist on the way.

 

[KidVermicious]

Good thing I have a hoist on the way.

He's getting in deep, boys. I think this one's addicted already.

 

[nevada]

what transmission does it have?


I know a guy that had a truck with the 3.0 and an auto, diagnosed with a rod knock..
he paid someone a shitton of money to rebuild it.
NO CHANGE in the sound.

he never had any problems with how it ran, or using oil, or anything else.

I cant remember for sure, but I want to say he ended up paying someone else, to pull the motor, and rebuild/check it again.
and again, NO CHANGE.

I finally got a chance to check it out. at first glance(first hear? lol) I would have also said bottom end, or rod knock.
but after his story of having it rebuilt already, I suspected that wasn't the case. after checking a bit more, it turned out it was the flexplate.

the TC was knocking against the mount bolts. someone had used the wrong bolts, or had left out the washers, OR, not sure what happened. the bolts were tight, but NOT tight against the flexplate.


I pulled the trans, and had the mating points(the flats around the bolts) resurfaced, since they were polished smooth, and I wanted it to grip the flexplate, AND be perfectly flat, put in new bolts with Loctite and no more sound.

sorry that was so long...


I guess what im saying is VERIFY where the sound is coming from before you start tearing it apart.

 

[brocktice]

Putting it up today and starting on dropping the diff and oil pan to verify.

EDIT: We'll see how it looks. If the bearings are worn but the crankshaft measures out good and doesn't look awful, I may just replace the bearings. If the crankshaft is beat up I may go for a used reground shaft. The rest of the engine appears to be in good shape at this point, HG not leaking, etc, so for the sake of time and money I may put off a full rebuild.

If I find upon opening it that a bunch of stuff is hosed, out it comes.

 

[brocktice]

Time to get this party started!