A shout out to all here! Been working on vehicles all my life. I just seem to be noticing that these 4.3's may not be that strong from the factory after changing so dam many knocking engines. Anyone out there pulled one down that has been knocking and found any common problem areas that are notorious. I just wondering if mine will be rebuildable when i pull it.

 

It's a good strong engine, if it's taken care of. Common problem is lower intake gaskets leak coolant internally and contaminate the oil. The coolant will destroy main, rod, and cam bearings. How bad it is, depends on how long it was driven while knocking. Felpro MS98002T intake gaskets will not leak if clean up and installation is done properly. Lotta do's and dont's when doing the job.

 

All GM 6s seem to suffer that lower intake issue, the dam crap dist caps you buy today have something to be desired. Trucks gotten about 20 miles on it since she started knocking, seems there were more issues with it than i first thought, but once a mechanic always a mechanic.Everyone has me work on theirs and mine never gets touched, LOL

 

1996 & newer 4.3L with CSFI, lower intakes are a problem when the OEM style gaskets are used. Felpro makes a new design that doesn't leak. 1995 and older with CMFI is a different design and they typically don't leak.