I either have a loose cap or wore bearing???, was wondering if anybody has had any experience just swapping out rod bearing with out a complete rebuild, car doesn't get driven much and probably wont so was just looking to do a quick fix until a later date, Motor runs and no noise at idle or until you reach about 3k rpm's then its just a slight knock.. looking for ideas to see if any one had a good experience just swapping the rod bearings? or any suggestions thanks!

 

Make sure the torque converter bolts are tight . Over the years I've seen several cars that folks swore had a "rod rap" end up being fixed by either tightening the loose torque converter bolts or replacing the cracked flexplate .....

 

I once bought a 130k mile, '82 Bonneville with a 4.1L that had a wiped out cam sproket for $300. Other than needing a timing chain it was in great cosmetic shape.

Only after I got it running did I discover it sounded like a diesel. Much worse on cold starts. I drove it daily over 100 miles without issues for another 120k.

All this to say that I would just wait until you can fix it proper (if it is in fact a lower end issue).

 

Could be wrong but I heard the old 305 engines have a slight, yet consistant issue building up proper oil pressure upon initial start-up and sometimes get a top-end knock until the oil pressure builds-up and gives the engine proper lubrication. I've never heard mine do it, but I suppose it is definitely plausible that could be happening to yours. Hopefully that's all it is.