| Sign of malfunction | Cause of malfunction | Method of elimination |
| Knocking noise when starting a cold engine that then stops | Normal phenomenon | The knocking stops once the oil pressure reaches normal values |
| Knocking for a long time when starting an engine that has not been running for 48 hours or more | Oil leakage from the high pressure chamber of the tappets and air getting into it | The knocking should stop within 15 minutes when the engine is running at 2000-3000 min⁻¹ |
| Constant knocking noise when first starting the engine after assembling the cylinder head | Insufficient oil supply to the cylinder head oil line | Ensure normal oil supply to the cylinder head oil line |
| Constant knocking during engine operation after prolonged cranking by the starter or by the wheel | Oil leakage from the high pressure chamber of the tappets and air getting into it | Ensure normal oil supply |
| Constant knocking noise when engine is running after replacing tappets | Insufficient oil supply to the tappets | Ensure normal oil supply |
| Constant knocking noise at idle after engine operation at high crankshaft speed | Engine oil level is above or below normal Large amounts of air entering the oil when the engine is running at high crankshaft speed Deterioration of oil quality | Check the oil level and restore it to normal if necessary Check the lubrication system Check the quality of the oil |
| Knocking when the engine is running for 15 minutes or more | Low oil pressure Pushrod failure | Check the oil pressure and supply to all engine components Remove the cylinder head cover and check if the tappet plungers move when pressed with a finger. If the plunger moves, replace the tappet |
(The material was obtained from a web resource: www.hyundaibook.ru)