rod bearing = poop

3.0 GT

3.0 GT

2JZ Holset Mafia
Nov 30, 2008
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Franklin, Tn
ok i bought my 89 turbo a while ago and completely rebuilt the engine. new crank, pistons, rings, bearings, gaskets and seals all around, arps, hks mhg and a few others. i put the engine in the car and broke it in. all of a sudden around 500 miles i start to hear a slight knocking. i thought it might be the freezing temps. guess not. it gets worse and i drop the engine :(. i was sad and took off the oil pan. checked the rods and noticed number 2 was loose. took off the cap and there was the knock. my bearing was flattened and squished out the sides a little. the rod is fine, the bearing is shot (easy fix) but i dont know about the crank. for the most part the journal is ok except on one half from one oil hole to the other is a hair pin size groove. it is not to deep but i dont know if it will cause problems. what should i do. i just got the crank too. :1zhelp:
 
JDMMA70

JDMMA70

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Dec 4, 2006
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Even though its a hassle id get the crank checked out by the machine shop or you can check it yourself with a mic.
 
3.0 GT

3.0 GT

2JZ Holset Mafia
Nov 30, 2008
381
1
0
Franklin, Tn
JDMMA70;1227332 said:
Even though its a hassle id get the crank checked out by the machine shop or you can check it yourself with a mic.
Click to expand...

i have a mic and the tolerances are in spec with the manual its just the small groove in the middle im worried about.
 
grimreaper

grimreaper

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Jul 2, 2008
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have it polished, i guess you were hoping to avoid removing the crank?

Any idea why it started knocking? what do the other bearings look like? sucks to hear about this on a fresh build, good luck!
 
3.0 GT

3.0 GT

2JZ Holset Mafia
Nov 30, 2008
381
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Franklin, Tn
grimreaper;1227495 said:
have it polished, i guess you were hoping to avoid removing the crank?

Any idea why it started knocking? what do the other bearings look like? sucks to hear about this on a fresh build, good luck!
Click to expand...

well that and having to get it machined. i dont want anymre costs. lol. if i were to leave it would oil preessure drop? and the other bearings are all good.
 
WhtMa71

WhtMa71

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Apr 24, 2007
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If you don't get it checked by a machine shop you run the risk of it happening again within short order. You chose the wrong car to try and be cheap with haha..
 
Jeff Lange

Jeff Lange

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Mar 29, 2005
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Get the crank polished and replace the No.2 bearing, replace all the gaskets, and make sure everything is torque properly.

As long as everything else was done properly before, this should be all that is needed.

Jeff
 
Keros

Keros

Canadian Bacon
Mar 16, 2007
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Why did only #2 rod bearing die? I think it's worth checking all the oil galleries leading to that bearing to make sure it's getting full flow. I don't think the bearing gods just decide a bearing is doomed to die; it dies for a reason ;)
 
WhtMa71

WhtMa71

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grimreaper;1228052 said:
^ why? If it was polished out what caused it to fail again.
Click to expand...

Most machine shops will at least check the journals to make sure they're round before they get polished. If they're not they have to machine the journals.

If you polish an egg-shaped journal, it still doesn't work very well.
 
N

nikwal

[Shitx0rZ DeluX]
Jan 20, 2009
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Västerås
Seems to me many people focus much on the crank, forgetting measuring the holes in the rods/block.. I almost got declared an idiot around here for correcting rondness on the engine, at least until I started and used the engine :p..
Hmm ahh and also, goodson has stuff for building your own polishing machine, it aint hard, just look at the one they have and improvise..
 
3.0 GT

3.0 GT

2JZ Holset Mafia
Nov 30, 2008
381
1
0
Franklin, Tn
nikwal;1229038 said:
Seems to me many people focus much on the crank, forgetting measuring the holes in the rods/block.. I almost got declared an idiot around here for correcting rondness on the engine, at least until I started and used the engine :p..
Hmm ahh and also, goodson has stuff for building your own polishing machine, it aint hard, just look at the one they have and improvise..
Click to expand...

well it turns out all the bearings are shot. the mains too. im going to take the crank to a shop to get it looked at. hopefully it wont cost to much
 
Jeff Lange

Jeff Lange

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He is correct though, you need to make sure the block and rods are round as well. Don't just give them the crank without checking these, as you'll have a perfect crank with messed up bearings once again.

Jeff
 
3.0 GT

3.0 GT

2JZ Holset Mafia
Nov 30, 2008
381
1
0
Franklin, Tn
Jeff Lange;1229058 said:
He is correct though, you need to make sure the block and rods are round as well. Don't just give them the crank without checking these, as you'll have a perfect crank with messed up bearings once again.

Jeff
Click to expand...

is there a chart somewhere so i can narrow down what actually happened to the bearings? i didnt change the oil like i should have after a fresh rebuild.
 
3.0 GT

3.0 GT

2JZ Holset Mafia
Nov 30, 2008
381
1
0
Franklin, Tn
yz-125;1229753 said:
According to the chart the bearings died from dirt particles in the oil. The ends of the crank around the journal are blue on the end. The bearings aren't blue from heat though. I wonder why that happened.
Click to expand...

got the crank checked out at a machinme shop and they said it was fine. the kournals are is spec almost perfectly
 
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