i have a 1992 prelude with a 96 h22a1 vtec jdm i have just recently purchased and installed. after replacing several defective minor parts, i had to replace new timing belt and auto tensioner. i also purchased a chipped p72 ecm and i am basicaly all stock. car ran great!!! the other day we noticed a knocking sound at around 1k to 2k rpm range. it is barely noticable at idle and only at the above range rpm's. we dropped the oil pan and removed each rod bearing and they have no wear, scars, scratches, etc... crank turns easily with no spark plugs, no burnt looking parts. however, when you look in the oil...you can see very small minor metal spots mixed in the oil, kind of like a metal flake paint job, but just not as much. we had the swap done at a local shop who robbed us and who knows what they did or did not do. someone suggested the manual tranny bolts on the fly wheel. sounds more like the noise is coming from the belt end of engine and mmay be the power steering pump? takin off belt now to see if noise goes away. if not and after already checking the rod bearings, which look brand new, where else could such a knock come from. p.s. we have checked valve lash per fsm and replaced the lm assemblies. we are stumped!!! who is the man out here with the correct solution...short of me puting a 50 cal round through the block? plz. send me back some constructive advise. thanks in advance.....T.

 

The main bearings are probably out of specs my block was doing the same thing knocking at upper rpm range and i took it apart the crank and bearings where all fine no scratches or nothing it lost power too so if that's your problem it's the bearings being out of spec.

 

That also explains the metal in the pan. Sounds like parts of bearings to me. I bought a junk engine for rebuild and it had 1/2" flakes of metal in the pan from the bearings eating themselves. GL and hope you get it sorted.
Mike

 

96 h22a1 is usdm not jdm most id think would be rods but if what theyre saying is its out of spec i say since your tearing it get new rods

 

we found that when you engage the clutch pedal.....the noise would almost go away. the shop had a hard time matching a new clutch fly plate combo on the car and who knows what they did in there. seems the bolts on the fly wheel may be the issue. will let everyone know, in the process of pulling tranny. thanks for the input so far! did not know the 96 was a usdm. thanks.

 

we checked all numbers and checked with seller from JAPAN.....ALL numbers says it is a 96 JDM! But that is a non issue at this point. Maybe they made both? seems To be the case. anyway, if it is not FLY WHEEL bolts, then we will change out THE ROD bearings. this engine ran like a swiss clock and still has all its power...no loss! just all of a sudden the knocking sound occured. if you knew the trouble we had with the PRO-TECH HONDA SPECIALISTS IN DECATUR, AL. You would understand what we have been through. it was an h22 to h22 swap, crated motor from japan to pro tech who took 4 months? to do the swap? amazing what we have had to go back and fix what they messed up! motor had a warranty, but now because we are on bad terms with shop....we cannot allow them to do another SWAP by returning this engine to seller and he send another. will keep all who is interested posted! thanks again.....T.

 

Wow that's ridiculous that shop is crap. Maybe throw out bearing? Only reason i say that is you said it will go away when you step on clutch unless I read wrong pretty sure the a1 is usdm just saying

 

Throw out bearing is my guess.

F22 to H22 swap took me 9 nights to do my first time, 7 of those work nights. Figuring the shop did an OBD2 -> OBD1 conversion it might take them a week for someone that knows what they are doing and taking their time. This is one of the most straightforward swaps there is.

 

My prelude did the same thing and it was the fly wheel bolts, well bolt. Just like u said everything was fine and power is still there. If u run into more problems and cant fix it yourself, I know I honest guy in bham area, just pm me I know it's a drive so Maybe not to realistic.

 

well folks.....it was two loose fly wheel bolts!!! whew! but, what a bXXXtch to repair on our own and all this from pro tech not torqing the bolts on the engine swap! runs like a sewing machine again! thank you all for your suggestions. also, please let me know your man in b,ham. it never hurts to keep others that are good for future issues. peace...T. p.s. the engine is a h22a jdm. my bad on saying it was a h22a1. which is a usdm! my hat off and my apology. i just got my number screwd up.

 

I will send u a pm and glad its working on, well some what of a way for u. Good luck if u come down this way sometime give me aheads up to.

 

well, have not had much time...but we did do a head job, all new valves and then we put new rod and main bearings it her and she is still making that same noise???could the balancer shafts cause this..thats all that is left in the engine that moves and we have not replaced. lmao, all while crying at da same time.