Hyundai Sonata LF Quiz
Engine Mechanical System

Troubleshooting

In this manual: Engine Mechanical System
General Information — 9Engine Mechanical System — 90Engine Electrical System — 58Emission Control System — 24Engine Control System/Fuel System — 114Drive Shaft and Axle — 15Suspension System — 35Steering — 19Restraints — 50Brake System — 54Body (Interior and Exterior) — 213Body Electrical System — 241Heating, Ventilation, and Air Conditioning — 56DCT (Dual Clutch Transmission) System — 52
~4min read

Troubleshooting

Symptom Suspected Area Remedy
Engine misfire with abnormal internal low engine noise. Flywheel loose or improperly installed. Repair or replace the flywheel if necessary.
Worn piston rings.
(Oil consumption may or may not cause engine misfire.)		 Inspect the cylinder for loss of compression.
Repair or replace if necessary.
Crankshaft thrust bearings worn. Replace the crankshaft and bearings if necessary.
Engine misfire with abnormal valve train noise. Valves stuck.
(Carbon on the valve stem may cause the valve to close improperly.)		 Repair or replace if necessary.
Excessively worn or displaced timing chain. Replace the timing chain and sprocket if necessary.
Worn camshaft lobes. Replace the camshaft and MLA.
Engine misfire with coolant consumption.
  • Defective cylinder head gasket and/or cracks or other damage to the cylinder head and cylinder block cooling system.
  • Coolant consumption may or may not cause engine overheating.
  • Inspect the cylinder head and cylinder block for damage to the coolant passages and/or a defective head gasket.
  • Repair or replace if necessary.
Engine misfire with excessive oil consumption. Wear of valves, valve guides and/or valve stem oil seals. Repair or replace if necessary.
Worn piston rings.
(Oil consumption may or may not cause engine misfire.)		 Check the cylinder for loss of compression.
Repair or replace as necessary.
Engine noise on start-up that lasts only a few seconds. Incorrect oil viscosity. Drain the oil.
Fill with oil of the correct viscosity.
Worn crankshaft thrust bearing. Inspect the thrust bearing and crankshaft.
Repair or replace as necessary.
Excessive engine noise regardless of engine speed. Low oil pressure. Repair or replace if necessary.
Broken valve spring. Replace the valve spring.
Worn or dirty valve lifters. Replace the valve lifters.
Stretched or broken timing chain and/or damaged sprocket teeth. Replace the timing chain and sprockets.
Worn timing chain tensioner, if equipped. Replace the timing chain tensioner if necessary.
Worn camshaft lobes. Inspect the camshaft lobes.
If necessary, replace the camshaft and valve lifters.
Worn valve guides or valve stems. Inspect the valves and valve guides, then repair if necessary.
Stuck valves. (Carbon on the valve stem or valve seat may cause the valve to remain open.) Inspect the valves and valve guides, then repair if necessary.
Low engine noise regardless of engine speed. Low oil pressure. Repair or replace damaged components as necessary.
Flywheel loose or damaged. Repair or replace the flywheel.
Damage to oil pan, contact with oil pump strainer. Inspect the oil pan.
Inspect the oil pump strainer.
Repair or replace as necessary.
Oil pump strainer is loose, damaged, or clogged. Inspect the oil pump strainer.
Repair or replace as necessary.
Excessive piston-to-cylinder clearance. Inspect the piston and cylinder bore.
Repair as necessary.
Excessive clearance between piston pin and bore. Inspect the piston, piston pin and connecting rod.
Repair or replace as necessary.
Excessive connecting rod bearing clearance. Inspect the following components and repair if necessary.
  • Connecting rod bearings.
  • Connecting rods.
  • Crankshaft.
  • Crankshaft journal.
Excessive crankshaft bearing clearance. Inspect the following components and repair if necessary.
  • Crankshaft bearings.
  • Crankshaft journals.
Incorrect installation of piston, piston pin and connecting rod. Make sure the piston pins and connecting rods are installed correctly.
Repair as necessary.
Engine noise under load. Low oil pressure. Repair or replace if necessary.
Excessive connecting rod bearing clearance. Inspect the following components and repair if necessary.
  • Connecting rod bearings.
  • Connecting rods.
  • Crankshaft.
Excessive crankshaft bearing clearance. Inspect the following components and repair if necessary.
  • Crankshaft bearings.
  • Crankshaft journals.
  • Cylinder block crankshaft bearing bore.
Engine does not start (crankshaft does not rotate). Hydraulic lock cylinder.
  • Coolant/antifreeze in cylinder.
  • Oil in cylinder.
  • Fuel in cylinder.
 Remove the spark plugs and check for fluid.
Inspect for a broken head gasket.
Inspect the cylinder block or cylinder head for cracks.
Inspect the fuel injector and/or fuel regulator for sticking.
Broken timing chain and/or timing chain sprocket. Inspect the timing chain and sprockets.
Repair as necessary.
Foreign object in the cylinder.
  • Broken valve.
  • Piston material.
  • Foreign material.
 Inspect the cylinder for damaged components and/or foreign material.
Repair or replace as necessary.
Seized crankshaft or connecting rod bearings. Inspect the crankshaft and connecting rod bearing.
Repair or replace as necessary.
Bent or broken connecting rod. Inspect the connecting rods.
Repair or replace as necessary.
Broken crankshaft. Inspect the crankshaft.
Repair or replace as necessary.

Test yourself

A quick Hyundai Sonata LF quiz: every answer comes with an explanation and a link to the manual page.