I tried that first on mine but the end of my rod had stretched. Maybe you're luckier than I am.

 

That sucks. More than likely i'm not luckier than you. I have an offer of 1200 already. I was upfront about the issue. Only paid 900 for so thats not too bad. I might throw it on craigslist and test the waters.

 

After going through all the work of pulling the head on mine and still not knowing for certain that a rod replacement will fix the issue (crank could be out of round) I'm wishing I would have sold it as it was. You can always use the money toward another one.

 

Well, I spent the morning dropping the diff and getting the oil pan off. I'm not sure how bad it is though. First inspection, I rotated the crank to give each rod end the "wiggle test." Just a slight front to back play, which I think is normal, but no up and down movement. Also, none the rod ends looked burned or darkened. The knock hasn't gone on for more than 2 weeks with less than 100 miles. So far I only removed the first two rod caps. The first one (closest to the crank) looks like something got in there and left a rough streak. Hard to explain, not grooved really. I can barely catch my nail on it. The bearing has a similar mark on it.

So, right off the bat I can't afford to pull the motor, rebuild, whatever. I'd love to though. #2 looked fine, obviously not brand new from the machine shop nice, but no weird wear on the journal. Heres a picture, I think it looks worse in the pic than in person, i don't know. Do you think its possible to smooth that rough part out enough to last me a little while? Maybe a little crocus cloth? I know it won't be perfect but at least my bearings weren't worn to nothing like I was expecting.

 

Just an update. Pull all the rod caps and only #1 any "scuffing". I couldn't catch my fingernail on it, kind of like a rough streak. Looks like something made its way into the hole of the bearing. Anyways, not trying to dump much money into this motor, I cleaned it up and put in new bearings. Plastigaged them (i know) and still falls within spec.

Button it all back up and it take it for a spin. The second I let the clutch out and put a load on it the tapping is present. I was stumped. At least if my crank was shot I'd get at least a few seconds of no knocking till the bearing toasted again. I've been driving it the last few days to work and back trying to really hear the "knock." I've heard rod knocks before and this doesn't quite sound right. Its more of a tap, not a valve tap though. If I cruise around 2.5k rpm where the muffler doesn't drone much, I can hear a light tapping PLUS a flapping/fluttering sound. WFT. Never heard this before.

Mind you this "knock" never existed until after I changed my timing belt/upper idler.

I get home, pop the hood, looking around after hearing the new noise. First thing I notice is the timing belt has a looseness under the upper idler. Not enough to skip a tooth, but close. I'm thinking the hydraulic tension took a crap on me when I compressed it to re-install during the tb job. I stuck it in a bench vice and it was almost stuck, then popped in. Not a real slow retraction. I didn't think much of it when it happened.

Anyhoo, my hopeful theory is that the tensioner crapped out and is letting the idler bounce off the metal tip. Also, when the belt has lost tension, the idler pulley has side to side play(new pulley) and makes a knocking sound against the front of the block. If I use a screwdriver to pry pulley back up to apply tension, there is zero play in it. Either way i'm picking up a new tensioner on thursday and we'll see if this was it or not. I'm prepared for the worst though. Oh, and the only thing that keeps me thinking that this is the problem is because every once and awhile it won't knock at all going through the gears. Come to a stop sign and it'll do it again. Usually rod knock stick around once they show up.

 

I just wanted to update this. Replace the tensioner and all is well. No more knocking. My timing belt didn't "look" loose when idling, but I think under a load it was allowing the side to side play on the tensioner and slapping against the block.