bennyboyraptor

So I recently rebuilt my motor, bought everything brand new except for the block, picked one up from a machine shop that had crankshaft, pistons, rings and rods. So I put all my new parts onto that block and she ran like a dream for about 1,000 miles. Last night me and a buddy took her for a cruise and it developed a small knock, which gradually got louder, So I limped it home and havent looked at it since. I sit here typing this post wondering what the heck happened, we broke it in ti spec and have not had any problems with it prior to this. I am hoping that maybe my timing jumped a tooth or one of the valves loosened up. Any one have any ideas? I will probably tear into it some time this week.

budro

First off sorry to hear about that, but yeah with a knock that starts off quiet then gets louder and louder it ought to be a rod bearing that gradually chewed itself up. I don't know what you ride but from your avatar It looks like a 4x4. So going in from the oil pan to change it out would probably be just as much of a pain as pulling the engine with the front diff. in the way. If you do have easy access to your oil pan then it might be an easy fix.

bennyboyraptor

Thanks. It is an 86 4x4 with a solid axle and high steer, I have plenty of access to my oil pan. It started as a quiet barely noticeable tick, then gradually got louder.

budro

Actually, what am I thinking. Drain your oil and feel around for any aluminum bits before you tear into anything. I bet my right nut that you'll find out real easy that-a-way. Maybe even strain the oil with some t-shirt clothe. That'll get you your answer real quick.

snobdds

Your suppose to go back in and readjust the valves after the 1st 500 miles. Also check your head bolt torques and make sure they are at spec.

My guess is it's your valves getting broke in...

bennyboyraptor

Well I pulled the oil pan and valve cover yesterday, visually everything looked alright. Well after poking around a bit I found the source of my problem, where the connecting rod connects to the crank there is a little bit of side to side play. When I say little bit I mean maybe a quarter inch or so. So I am pretty sure it is that bearing, here are some pics.

bennyboyraptor

I forgot to mention that the valves were within spec as well.

budro

Wow this is a tough one. The bearing ate itself up for a reason so just replacing it through the oil pan opening might just be a temporary fix, but it's probably so tempting I bet. What are you planning on doing? Is it even worth taking it back to the machine shop so they can handle it?

ohyeahcrx

So was the engine a complete rebuild? All the bearings were replaced and everything? What could have caused this? Not plastiguaging it correctly within spec?

bennyboyraptor

I bought a machined head with pistons, rods and the crank already installed. What happened was a guy was building a mini truck, but his truck got wrecked before he could install the new block. But I had my head re done, new oil and water pumps along with a new clutch and all new gaskets and seals. I will probably just replace that bearing and see what happens. I really really do not want to pull the engine again.

bennyboyraptor

So any ideas? should I just get a new bearing and see how long it lasts?

ohyeahcrx

Since you already have the oil pan off thats what I would do.

budro

x2 I had a buddy that made it like regular maintenance on a Celica. Just always kept a few of the bearings on hand and recycled the oil. Probably did that for about a year until he was ready to pull the engine, but yeah I'm afraid if it happens once it'll happen again and that is something that you'll have to be prepared for, mentally anyways.

hilux1026

ok so i have touched on this one before.

Most machining companies dont do a very good job of cleaning the crank once it has been ground. Wehn re-assembling an engine be very sure that you clean out all journals and oil passages within the crank. It takes a while but it is insurance well worth the time. Degreaser and an air hose with 90psi behind it is good but make sure you change out the degreaser often as you might be re-introducing the metal particules back into the journals.

For a start pull the rod bolts and visually check the crank and make sure no marks. Check the crank journal with a caliper digital or otherwise for being round and not slightly oval. Check the ports within the crank to make sure that there is no metal within the oil hole.

also check that there is oil on that part of the crank as this will tell you about the top half of my post.

If all that is ok then replace the bearing keeping in mind the notches on the bearing shells and the caps. I have also seen these placed in backwards and then close on the crank. This would make it tight but i have also seen guys just keep turning until it free's up. Not to say that the person you bought it from was unscrupulous but i have seen a lot of things in my time and when you dont know the real history of what your buying you just dont know.

I wrote all this as i dont want to see you have to pull the whole thing again in a week or two when this happens again. It gets painful after a while. Experience with this is what taught me.

Hope this helps.

bennyboyraptor

Thanks for all the info guys, I will let you know how it goes. What is the place place to order the bearing from?

modlite

There's naturally some side to side play in the connecting rod, i'm wondering if they didn't use assembly lube in the process and it nicked it on first start up and started getting gradually worse from there. Or like others said it wasn't plastiguaged.

I did the rob bearings on my truck at 160k, and they're holding up so far (knock on wood).

camo31_10.50

what's the point in doing the plastigauge?

bennyboyraptor

Thats what i am thinking, there is a little gouge in the block where it was hitting. I am just going to throw a new bearing in and see what it does.

p/u_4runner

i had the same problem with my first engine but i didnt get new rods when i rebuilt it, lesson learned. plastigauge, the way to go make sure the rod is i right direction of travel as the locks for the bearings and toyota weak for #2,rod brg. pull all the caps # them 1-4 and look for the groove, bearing knotch on the rod and make sure there all facing the same side of the block and match the rod cap with the knotch in the rod.. make sure theres no nail haingers for the bearing surface on the crank shaft if a little, i mean a little sand it smooth with some 'really' fie sand paper and clean oil ports with air install new brgs. and hope for the best.... you tried if it dont work get crankshaft machined agian and get on ebay type in H beam rods for toyota and go that route then youll have a BADASS bottomend, too many rpms you woul need more head wore these rods are guaranteed to 9000 rpm.. but try and repair it its cheaper maybe you got a cap on backwards???

bennyboyraptor

Well it ended up being a spun bearing.