Passat L4-1984cc 2.0L DOHC (1991)
Spark Plug: Testing and Inspection
Checking Spark Plug For Wear, Damage, Or Deposits
1.
Remove spark plug wire and spark plug.
Visual Spark Plug Inspection
2.
Inspect the spark plug for:
a. Improper gap
b. Carbon deposits
c. Cracked center electrode insulator
d. Burned or worn electrodes (may be caused by):
Excessive mileage
Lean fuel mixture
Advanced ignition timing
Loose spark plug
Plug heat range too high
Insufficient Cooling