Hyundai Elantra MD/UD: Troubleshooting - General Information - Engine Mechanical System - Hyundai Elantra MD 2010-2015 Service manualHyundai Elantra MD/UD: Troubleshooting

Troubleshooting

Symption
 Suspect area
 Remedy
Engine misfire with abnormal internal lower engine noises
•
Worn crankshaft bearings
•
Loose or out of specification engine flywheel
•
Replace the crankshaft and bearings as required.
•
Repair or replace the flywheel as required.
Worn piston rings
(Oil consumption may or may not cause the engine to misfire.)
 Inspect the cylinder for a loss of compression.
Repair or replace as required.
Worn crankshaft thrust bearings
 Replace the crankshaft and bearings as required
Engine misfire with abnormal valve train noise
 Stuck valves
(Carbon buidup on the valve stem)
 Repair or replace as required.
•
Excessive worn or mis-aligned timing chain
•
Out of specification valve clearances (MLA)
Replace the timing chain and sprocket as required.
Worn camshaft lobes
 Replace the camshaft and valve tappet (MLA).
Engine misfire with coolant consumption
•
Faulty cylinder head gasket or other damage to the cylinder head and engine block cooling system
•
Coolant consumption may or may not cause the engine to overheat
•
Inspect the cylinder head and engine block for damage to the coolant passages and/or a faulty head gasket.
•
Repair or replace as required.
Engine misfire with excessive oil consumption
 Worn valves, guides and/or valve stem oil seals
 Repair or replace as required.
Worn piston rings
(Oil consumption may or may not cause the engine to misfire)
•
Inspect the cylinder for a loss of compression.
•
Repair or replace as required.
Engine noise on start-up, but only lasting a few seconds
(Check and compare with known good vehicle to determine normal condition.)
 Incorrect oil viscosity
•
Drain the oil.
•
Install the correct viscosity oil.
Worn crankshaft thrust bearing
•
Inspect the thrust bearing and crankshaft.
•
Repair or replace as required.
Upper engine noise, regardless of engine speed
 Low oil pressure
 Repair or replace as required.
Broken valve spring
 Replace the valve spring.
Worn or dirty valve tappet (MLA)
 Replace the valve tappet (MLA).
Stetched or broken timing chain and/or damaged sprocket teeth
 Replace the timing chain and sprockets.
Worn timing chain tensioner, if applicable
 Replace the timing chain tensioner as required.
Worn camshaft lobes
•
Inspect the camshaft lobes.
•
Replace the camshaft as required.
•
Out of specification valve clearances (MLA)
•
Worn valve guides or valve stems
Inspect the valves and valve guides, then repair or replace as required.
Stuck valves (Carbon on the valve stem or valve seat may cause the valve to stay open.)
 Inspect the valves and valve guides, then repair or replace as required.
Worn drive belt, idler, tensioner and bearing
 Replace as required.
Lower engine noise, regardless of engine speed
 Low oil pressure
 Repair or required.
Loose or damaged flywheel
 Repair or replace the flywheel.
Damaged oil pan, contacting the oil pump screen
•
Inspect the oil pan.
•
Inspect the oil pump screen.
•
Repair or replace as required.
Oil pump screen loose, damaged or restricted
•
Inspect the oil pump screen.
•
Repair or replace as required.
Excessive piston-to-cylinder bore clearance
•
Inspect the piston, piston pin and cylinder bore.
•
Repair or replace as required.
Excessive piston pin-to-piston clearance
•
Inspect the piston, piston pin and the connecting rod.
•
Repair or replace as required.
Excessive connecting rod bearing clearance
 Inspect the following components and repair or replace as required.
•
The connecting rod bearings.
•
The connecting rods.
•
The crankshaft pin journals.
Excessive crankshaft bearing clearance
 Inspect the following components, and repair or replace as required.
•
The crankshaft bearings.
•
The crankshaft main journals.
•
The cylinder block
Incorrect piston, piston pin and connecting rod installation
•
Verify the piston pins and connecting rods are installed correctly.
•
Repair as required.
Engine noise under load
 Low oil pressure
 Repair or replace as required.
Excessive connecting rod bearing clearance
 Inspect the following components and repair or replace as required:
•
The connecting rod bearings
•
The connecting rods
•
The crankshaft
Excessive crankshaft bearing clearance
 Inspect the following components, and repair or replace as required:
•
The crankshaft bearings
•
The crankshaft main journals
•
The cylinder block
Engine is not cranked.
Crankshaft does not rotate.
 Hydraulically locked cylinder
•
Coolant/antifreeze in cylinder
•
Oil in cylinder
•
Fuel in cylinder
1.
Remove spark plugs and check for fluid.
2.
Inspect for broken head gasket.
3.
Inspect for cracked engine block or cylinder head.
4.
Inspect for a sticking fuel injector and/or leaking fuel regulator.
Broken timing chain and/or timing chain gears
1.
Inspect timing chain and gears.
2.
Repair as required.
Material in cylinder
•
Broken valve
•
Piston material
•
Foreign material
1.
Inspect cylinder for damaged components and/or foreign materials.
2.
Repair or replace as required.
Seized crankshaft or connecting rod bearings
1.
Inspect crankshaft and connecting rod bearing.
2.
Repair as required.
Bent or broken connecting rod
1.
Inspect connecing rods.
2.
Repair as required.
Broken crankshaft
1.
Inspect crankshaft.
2.
Repair as required.


Repair procedures
Compression Pressure Inspection If the there is lack of power, excessive oil consumption or poor fuel economy, measure the compressi ...

Special Service Tools
Special Service Tools Tool (Number and name) Illustration Use Crankshaft front oil seal installer (09231-2E000) (09231-H1100) ...