| The Problem | Is Caused By | What To Do |
|---|---|---|
| Connecting rod bearing noise | Insufficient oil supply | Inspect for low oil level and low oil pressure |
| Carbon build-up on piston | Remove carbon from piston crown | |
| Bearing clearance excessive or bearing missing | Measure clearance, repair as necessary | |
| Crankshaft connecting rod journal out-of-round | Measure journal dimensions, repair or replace as necessary | |
| Misaligned connecting rod or cap | Repair as necessary | |
| Connecting rod bolts tightened improperly | Tighten bolts with specified torque | |
| Piston noise | Piston-to-cylinder wall clearance excessive (scuffed piston) | Measure clearance and examine piston |
| Cylinder walls excessively tapered or out-of-round | Measure cylinder wall dimensions rebore cylinder | |
| Piston ring broken | Replace all rings on piston | |
| Loose or seized piston pin | Measure piston-to-pin clearance, repair as necessary | |
| Connecting rods misaligned | Measure rod alignment, straighten or replace | |
| Piston ring side clearance excessively loose or tight | Measure ring side clearance, repair as necessary | |
| Carbon build-up on piston is excessive | Remove carbon from piston | |
| Valve actuating component noise | Insufficient oil supply | Check for: (a) Low oil level (b) Low oil pressure (c) Wrong hydraulic tappets (d) Restricted oil gallery (e) Excessive tappet to bore clearance |
| Rocker arms or pivots worn | Replace worn rocker arms or pivots | |
| Foreign objects or chips in hydraulic tappets | Clean tappets | |
| Excessive tappet leak-down | Replace valve tappet | |
| Tappet face worn | Replace tappet; inspect corresponding cam lobe for wear | |
| Broken or cocked valve springs | Properly seat cocked springs; replace broken springs | |
| Stem-to-guide clearance excessive | Measure stem-to-guide clearance, repair as required | |
| Valve bent | Replace valve | |
| Loose rocker arms | Check and repair as necessary | |
| Valve seat runout excessive | Regrind valve seat/valves | |
| Missing valve lock | Install valve lock | |
| Excessive engine oil | Correct oil level | |