Assuming you've positively ruled out an exhaust leak, t sounds like it might be a stuck lifter or a valve tapping.

Perhaps a pushrod is stuck or bent. You'll need to take the valve cover off and observe the operation of the valves. Turn the engine by hand with the fan or hand crank and see if any aren't moving like they should.

Make sure you aren't low on oil in the crankicase.


1950 Chevrolet 3100 (Ol' Roy)

1939 Packard Standard Eight Coupe (The Phantom) | 1956 Cadillac Coupe de Ville (The Bismarck) | 1964 Ford Galaxie 500 coupe |1966 Ford Mustang (Little Red) | 1969 Pontiac GTO (The Dishpit) I 1979 Ford F-100 | 1976 Ford F-150 (Big Red) | 1995 Ford F-150 (Newt)