There are several possible sources of abnormal sounds in the compressor, depending on the system part that failed:
1. Abnormal sound in compressor crankcase
a) Excessive clearance of crankpin metal/piston pin bearing and main bearing
Set the proper clearance or replace.
b) Improper tightening of crankpin bolt/balance may mounting bolt
Tighten them to correct torque
c) Foreign matter trapped in the crankcase and the balance weight/crank arm, etc. are hitting it. Remove the foreign matter.
2. Abnormal sound from the compressor cylinder
a) Insufficient cylinder top clearance causing hitting to the cylinder wall.
Set the clearance to normal.
b) Broken pieces of the valve plate or piston ring in the cylinder.
Remove the foreign matter. Replace damaged parts.
c) Blow by sound of air due to abnormal wear of piston rings.
Replace the piston rings.
3. Echoing of abnormal sound at compressor valve seat
a) Inlet/discharge valve is the source of the noise: Valve plate and valve spring are damaged. Check the inlet/discharge valve and repair or replace.
b) Foreign matter in inlet/discharge valve
Remove the foreign matter.
c) Valve spring is stuck or cracked.
Replace the valve spring.
d) Valve vibrates because cylinder cover bolt is not properly tightened.
Tighten it properly.
e) Foreign matter or broken parts debris trapped in the valve chest
Remove the foreign matter
f) Flow on the valve chest clamping surface causing air leakage.
Correct the surface or replace if it is bad.
4. Abnormal sound in compressor oil separator
Foreign matter or broken parts debris trapped in the separator
Remove the foreign matter.
5. Abnormal sound in compressed air piping
Foreign matter or broken parts debris trapped in the piping
Remove the foreign matter.
