Loud engine clunking

[intense1]

So 20 minutes after I bought a second car last weekend, the (trusty?) 'ol LC started making a horrible noise. We shut her down and had it towed to my work where it can sit and there she is. I pulled the oil pan a few days ago, thinking that maybe I'd broken a rod, but everything looks good there. I pulled off the valve cover, and everything looks kosher there: all springs in place and all the pushrods looking good. I talked to some friends, and it was mentioned that perhaps one of the rod bearings died and I'm getting some slop there.
The clunking gets louder and speeds up with engine RPM, fyi.
Do any of you have any suggestions or experience with this?

 

[intense1]

bump.

 

[RockDoc]

Can you have a buddy turn it over with the crank nut or a belt and watch and listen to see if you can localize the sound?

 

[lehiguy]

If the pan is still off, you might think about pulling each rod bearing cap off one at a time. Rod knock intensity increases with RPM. Exhaust leak intensity decreases with RPM. Cruiser cranks are steel, not cast iron and can survive some nasty stuff if you get after it quickly.

 

[intense1]

I'll have to check the rod caps then. It's not an exhaust leak, I'm certain of that. Thanks!

 

[Red Rattler]

It will be a small end bearing. If the noiseis dull or not there at idle, but develops at higher rpm then it will be a small end as thats its simptoms.
Also if you have the sump off clean the rod caps and see if any are black in colour as this will indicate a bearing failure.

 

[cruiser88]

You need to guage rods and mains

also it would not hurt to pull the lifter cover/ gasket

 

[mdennis]

does the knocking go away at all at any speed?, mine was kinda here and there ended up being a loose flywheel just got thru puttin it back together yesterday morning. i drop the pan and was lookin at the bottom end and grabbed the flywheel and thats when i found out it was a hair loose, dropped the trans and retightened, and of course broke one bolt , but had a spare motor with the bolts still in it.sounded like it was rods knockin was glad and mad at the same time as im the guy who didnt tighten the bolts

 

[86beast]

I thought I had a rod knock problem as well. I'm new to FJ60's and didn't know what I had gotten into, it didn't sound good. It wasn't a consistant knock but when it did randomly knock it scared the crap out of me, it was loud and sounded like someone was hitting my block with a hammer. Me and a buddy started diagnosing it by pulling the alt/ps belt off and it still made the knock. We pulled the air pump belt off and it made my week, the knock was gone. Needless to say I just finished up my first desmog using Jim C's pulley and I'm running like new. Hopefully your problem is as simple as mine.

 

[CruisinFJ60]

my money is on a rod if it is pretty noticeable at idle and varies with rpm also would presume a knock that loud should be pretty obvious when the culprit bearing cap(s) come off.

 

[intense1]

So! I finally got under the cruiser and I've located the problem. The #1 rod bearing is shot. Anybody have a recommendation on where to get them? MAF has a set for $112.

 

[cruiser88]

if you do them with the crank installed do one bearing at a time.............dont pull them all and then change them

 

[intense1]

Cool, thanks for the tip!!

 

[fliphkd778]

How much slop could you feel and how loud approximately was the knocking?

 

[intense1]

The klunking was very loud, I though that the engine was going to come apart. There was maybe a 1/16th to 1/8th slop.

 

[cruiser88]

damn..........

The klunking was very loud, I though that the engine was going to come apart. There was maybe a 1/16th to 1/8th slop.

 

[intense1]

Just for closure, the #1 rod bearing was gone, (I think due to oil stavation. My fault) I could put up pics of it but I'm lazy. I replaced the rod bearings, and I think I'm good to go!

 

[fliphkd778]

The crank nor rod was damaged?