Hyundai Sonata 1991 Shop Manual page 42

Symptom
Noisy valves
GENERAL
Probable cause
Incorrect auto-lash adjuster
Thin or diluted engine oil (low oil pressure)
Valve stem or valve guide worn or damage
Remedy
Replace
Change
Replace
Excessively worn cylinder Shortage of engine oil
and piston
Dirty engine oil
Poor oil quality
Overheating
Wrong assembly of piston with connecting rod
Improper piston ring clearance
Dirty air cleaner
Add or replace
Check oil level on daily basis
Replace
Use proper oil
Repair or replace
Repair or replace
Replace
Clean air cleaner and
replace filter
Connecting rod and/main
bearing noise
Damaged crankshaft bearing
Excessive engine rolling and
vibration
Insufficient oil supply
Thin or diluted engine oil
Excessive bearing clearance
Shortage of engine oil
Low oil pressure
Poor quality engine oil
Worn or out-of round crankshaft journal
Clogged oil passage in crankshaft
Bearing worn
Bearing improperly assembled
Non-concentric crankshaft or bearing
Loose engine mounting bracket
Broken engine mounting insula~or
Loose transaxle mounting bracket
Broken transaxle mounting insulator
Loose front roll stopper
Broken front roll stopper insulator
Loose rear roll stopper
Broken rear roll stopper insulator
Check engine oil level
Change
Replace
Add or replace
Check oil level on daily basis
Adjust or repair
Use proper engine oil
Repair or replace
Clean
Replace bearing and check
engine oil lubrication system
Repair or replace
Replace
Re-tighten
Replace
Re-tighten
Replace
Re-tighten
Replace
Re-tighten
Replace
20-11