the_cynic

96 accord 4d EX, f22b1. 250k miles. OK story time. my valve cover gasket has been bad for some time. ( so don't yell about the dirty engine. this is what I originally set out to fix.) ..just recently the spark plug tube o-rings/gaskets have also given out, and my #1 and #3 spark plug tubes have been filling with oil. Amazingly, this doesn't really affect the way it drives, but I've been cleaning them out every week until I could get some time off to do some work, just cause it shouldn't be there. So. I've got those two wires out, paper towels stuffed in the tubes soaking up the oil. got distracted, doing something else, and then made the decision to just go get the gasket. Dumb*** me tries to start the car with only 2 cylinders firing. fluppetyflupeetyflup oh sh** turn it off. slap myself, hook the plugs up, start it up. all good. BUT WAIT. now I've got some crazy knock/chatter coming from the lower acc belt area.... fml. It's a nasty chatter, the kind a mechanic would DEFINITELY tell you is a rod cap or a spun bearing or something that costs WAY too much to fix. but I think I know better. (don't we all haha)

I rack my brain, f*** did I skip a tooth on the timing belt? did the tensioner fail? or worse did I spin a bearing or snap a pulley shaft? it kinda sounds like something stuck in the timing cover or a loose tensioner, mayybe, but. from my limited mechanic experience, it REALLY sounds like belt-slap. (loose timing/balancer belt hitting the timing cover when it slacks between compression cycles). it's about 180 degrees on the crankshaft as far as I can tell, two chatters per revolution. goes with the RPMs but doesn't really get crazy louder or scary sounding like a rod knock or broken piston, and is definitely coming from the bottom of the timing cover on the exhaust side. I know the oil pump is near there, but it's not really a broken oil pump kinda sound, it's more toward the cover, and oil psi is fine. It's not a grindy metal on metal sound, more like a clakety clack, and seems to be either IN the lower timing cover by the crankshaft, or just behind it in the oil pan. I'm figuring maybe the flopping around made the balancer shaft belt skip a tooth, leaving slappety slack down there. optimistic, right?

I read EVERY thread about timing belts and knocks I could find. lots of people finding problems I don't have. time to dive in .. I get the vc off, upper cover off, and start checking marks. f**k. everything lines up. yeah it's a good thing, but doesn't help me find my noise. I can even see down into the lower cover, the balancer shafts are right on, as well. (front one lines up with the pump casing, rear has a check slot) F**K. I can also see that the tensioners are in place with their springs and can't see any debris or belt damage anywhere. F**K. belt tension seems perfect. the belts are honda belts and only 4-5 years old. looking fresh as hell in there. IDK if the tensioners are original but it's rare that they actually fail, even the aftermarket ones. I want to avoid removing the crank pulley and lower cover because that means a walk to the auto parts store to get the crank tool. as far as i can tell, everything looks kosher in there. F**k.
OK well my plan of action is to re-tension the belts and hope that works. I know it's a fine line with these and two different tensions are required, but I'm thinking if the balancer shaft belt is the culprit, I can give both belts the timing belt adjust procedure, and that'll make the timing belt normal but tighten up the balancer belt more. Sounds good. I can avoid removing the crank pulley. (unless that makes it TOO tight, then I'll have to remove that and the lower cover, to do the proper procedure with the locking the timing tensioner 3 teeth tight and then getting the balancer tensioner just spring tension tight.)

I've torn into the thing, ready to crack that 14mm adjuster bolt for the tensioners. I decide it will be easier from below. I worm my way down there, and HOLD ON. WHAT IS THAT? the lower timing case looks .... odd. I think maybe p/o got frustrated with the cover (it happens) and didn't quite have it lined up when he bolted it back on. Investigating closer, I see that the cover is in fact broken, and the bolt is gone. it's all tweaked and sticking out from the block! I turn the crank, and hear (ever so slightly) the timing cover is contacting the BACK of the cranskhaft pulley, about twice per revolution. This is EXACTLY where my noise is coming from. I didn't see any contact marks on the pulley at first, because the thing just happened to be contacting it on that little rubber strip. it chewed about 1/16th off the rubber (harmonic balancer integrated I guess?) but nothing crazy. rotating the crank I can see it just slightly rubbing. the cover is a little loose in that area too, so this almost definitely explains why it would sound worse or better in random conditions. I don't know why my mistake with the spark plugs would make this issue present itself, though, that's my only doubt.

after reading so many scary stories of this noise meaning terrible things, I'm prematurely relieved right now that this might be a $0 fix. and I don't have to f**k with the timing belts. win-win. SO I'm gonna attempt to reposition the cover correctly. hopefully this is possible without removing the pulley, or else I'm taking a walk for that pulley tool. I'm thinking I can take the bolts off and maybe that will be enough to get it back aligned where it goes. I hope so. If it doesn't work, I'm gonna have to get creative with a retainer clip or something until I can get a new cover (oh joy I'll get to do this all again!)
wish me luck guys, I will update with results.