85 Salon engine knocking

[84dragcutlass]

Ok so i have an 85 salon with 76000 miles on it and the engine has a knock to it. Replaced the rod bearings and it still knocks. Sounds like a typical rod knock but i want to be sure before i try anything else. What should i do guys? I made a post in the wanted section for an olds engine just in case but id really hate to pull this clean engine

 

[pontiacgp]

a broken flex plate can make a sound like a bearing knock....it could also be a carbon knock..

 

[84dragcutlass]

seems random, i drove it today home from the guys house where we put the bearings in at and it didnt knock a bit the whole way, sounded really good, fired it up shortly after and it was knocking at idol. Would a flexplate or carbon do this? Ive broken flexplates before but never have had one really make much noise

 

[pontiacgp]

flexplate can do that....a bearing knock doesn't go away,...my old 305 would get a carbon knock every once in a while and I'd run water thru the carb while running to steam clean it. A carbon knock only shows up after the engine it at operating temp

 

[84dragcutlass]

Yeah i figured all the options like a bearing knock or maybe a wrist pin wouldnt go away, ever. Plus the thing just had new bearings put in it and it didnt last 5 minutes without knocking at the guys house. Ill check the flexplate tomorrow and see if i can see anything obvious