What was found
DURING AN APPROACH TO LANDING, PILOT REPORTED A VIBRATON IN THE LEFT ENGINE AND OIL LEAKING FROM COWLING. A PRECAUTIONARY SHUT DOWN MADE AND PILOT MADE AN UNEVENTFUL LANDING. INSPECTION REVEALED A HOLE IN NR 1 CYLINDER UNDER THE INTAKE PUSH ROD HOUSING. THE HOLE ALLOWED EXHAUST GASES TO BURN A HOLE IN THE PUSH ROD HOUSING ALLOWING OIL LEAKAGE, AND THE PUSH ROD TO BREAK. SUBMITTER SUGGESTED PROBLEM MAY HAVE BEEN DUE TO A POOR WELD.