Hookay- I have a 1989 4runner- 22re and its makin' a terrible knocking noise at all RPMs. It seems to be coming from the lower front of the engine.

I first thought it was the timing chain slappin' the cover. But I pulled it apart, the guides were intact, replaced the chain and guides with a set that had a metal drivers side guide, installed a new oil pump, I adjusted the valve clearances and buttoned it back up. Still have the noise.

Any ideas? Thanks!

rod end bearing worn? Have your tried to pull one of the plug wires with it running? if it goes away that will tell you what cylinder is knocking.

Sounds like a rod bearing to me. The noise you are hearing is the either the rod slapping the crank at TDC and BDC...or the piston smacking the cylinder head. Climb under the rig with engine idling..if the sound is amplified in the exhuast then its the second one. Time to start hunting for an engine or lining up your ducks for a rebuild. At the stage your engine is in (based on your description) simple bearing replacement is out of the question. Rods will need to be resized and the crank polished. If you wait to long and continue running the engine you can kiss any core value or rebuild options g-bye.

~Darin <img src="/forums/images/graemlins/baby.gif" alt="" />

Pulled the wires one by one and never had any noticeable change in the knocking noise.

Noise seems to get louder when the engine is warmed up.

The engine was rebuilt 35k mies ago- hate for it to be dying already but thems the breaks I suppose.

Thanks for the input

Have you backrolled the engine at all? As in did you turn it the opposite direction of operation when you were working on it? I had a problem years ago with a knocking sound and it turned out that I had backrolled the engine while I was trying to line something up and then started it. Any way it made an awful racket so I shut it off, rotated the crank in the proper direction a few revolutions by hand and then fired it up and it was fine after that. That was 5 years ago...

I'm kinda in the same boat as you. I rebuilt the motor about 1 1/2 years ago. Within the past few weeks, there has been a knocking that I have not located yet. I might have to pull the oil pan to check the rod bearings <img src="/forums/images/graemlins/frown.gif" alt="" />. I pulled the valve cover and the timing chain seems ok. I haven't checked the valve's yet, just checked by hand the rockers and all. Haven't done the pull the plug wire yet with it running. With such a recent rebuild, I'm kinda worried. Maybe we've got the same problem. If I find anything out I'll post it.

Well I really thought I had it. I firmed up the tension on my belts and my knocking stopped. Filled up with higher octane, ran some Seafoam. Ran really great for a week or two. I made the mistake of verbally stating how great it was running to my son and... yesterday on the drive home the knocking returned <img src="/forums/images/graemlins/angry.gif" alt="" />

Its weird though- this morning I cranked it up - no knock - let 'er idle to temp- no knock - drove down the street a mile or two (all the time I had)- no knock. I don't know what the heck is going on. Could a failing rod bearing come and go like that?