Originally Posted by 81scottsdale400
hey guys i need to know if you can help me diagnose the sounds of (if any at all) on how i would know if i broke a valve spring or bent a pushrod all i can tell you is its a 79 400 sb chevy 100 percent stock no peformance what so ever and after the snow it started knocking like crazy u can hear it clattering all around the truck and idk what is wrong and when your driving it you can hear something clattering but it only happens when its ideling or when u hit a certain rpm and if you give it a little bit of gas when your cruisin around please help me anyway possible thanx
The easiest way to "see" a bad spring or valve in general w/o removing the v-cover, is to use a vacuum gage. If the needle oscillates in time w/the miss or noise, that's an indication that it's valve related.
But, it sounds like you may have a bearing going bad. If you have an oil pressure gage, keep a close eye on it for lower than normal pressure- but the best thing is to stop driving it yesterday
and properly diagnose the problem before the engine is trashed.
A length of fuel hose held to your ear or a mechanic's stethoscope can help to isolate where the noise is coming from.