Geely EC718 2009 Workshop Manual page 409

Engine
2.6.7.12 Drive Belt Hum Sound Diagnostic
Diagnostic Tips:
Drive belt should not produce hum sound. If there is an intermittent noise, check the attached parts by changing the load. Make sure
that components run until the maximum load. These conditions may be due to (but are not limited to) over filling the air-conditioning
system, power steering system blocked or steering fluid incorrect, as well as the generator failure.
Fault Definition: Sustained High-Frequency Noise
Verify the fault. Does the engine hum appear?
Step 1
Yes
Remove the drive belt. Confirm whether the hum sound disappears?
Step 2
Yes
Check whether all attached drive pulley bearings are normal?
Step 3
Yes
To diagnostic tips.
Step 4
2.6.7.13 Drive Belt Off Diagnostics
Diagnostic Tips:
If the drive belt falls off from the pulley repeatedly, the reason may be the pulley misalignment. If the attachment drive belt driving
components cause the load fluctuates, it may cause drive belt fall off from the pulley. Test whether accessories driving parts are
working correctly. If the drive belt's length is not proper, drive belt tensioner will not be able to maintain a suitable drive belt tension.
Fault Definition: Drive belt falls off from the pulley, or incorrectly installed on the pulley.
Check the drive belt for damage. If necessary, replace the drive belt.
Step 1
Next
Check whether the pulley is misaligned. Repair the faulty part.
Step 2
Engine Mechanical System JL4G18-D
To diagnose Tips
No
(a) Remove the drive belt. Refer to
Replacement.
(b) Run the engine, but no more than 30 s.
Does the hum sound disappear?
Refer to
No
Pulley bearings should not appear stuck, loose and so on.
Replace the damaged pulley or bearing.
No
EC718/EC718RV EC715/EC715RV 10/2009
2.6.8.3 Drive Belt
2.6.7.4 Engine Noise Diagnosis
2-327