I have a 68 camaro 396, and just recently my engine makes a heavy thump and shakes the whole car at idle and while driving. It doesn't do it constant (like thump, thump, thmp ect..) just around every 5 to 10 seconds.

Any ideas what this could be? Drove fine for about 300 miles, but after I stopped for about 30 minutes it started.


Thanks in advance.

If you just installed the engine after being out of the car, start with a check of all torques of components that attach to any rotating assy....ie: Crankshaft pulley, fan assy, belts. Also check motor mounts to block; and mounts to subframe bolts. You may have a separated motor mount that may not be noticable all the time.

I will check the mounts. I haven't taken the motor out or recently added any componets, but I will check over everything though.

Found the problem. I took off my passenger valve cover and found one of my rocker arms broke off. Haven't checked the drivers, but hopefully that is the only problem. Could there be possible internal damage from the broken rocker arm? Thanks