Checks
| Action
|
DEFINITION: A mild
to severe ping, usually worse under acceleration. The engine makes sharp
metallic knocks that change with throttle opening.
|
Preliminary Checks
|
| • | Check the PCM grounds for being clean, tight, and in their proper
locations. Refer to
Wiring Repairs
in Wiring Systems. |
| • | If the scan tool readings are normal (refer to supporting text
of the Powertrain On-Board Diagnostic (OBD) System Check) and there
are no engine mechanical faults, fill the fuel tank with a regular unleaded
gasoline rated at 87 octane or higher and re-evaluate the vehicle's
performance. |
|
Fuel
System
|
|
Ignition
System
|
| • | Check the spark plugs for being the proper heat range. |
|
Engine
Cooling System
| Check for obvious overheating problems:
| • | Restricted air flow to the radiator or restricted coolant flow
through the radiator. |
| • | Check for the proper tension on the drive belts. |
| • | Check for a faulty thermostat. |
| • | Check for a correct coolant solution. The coolant should be a
50/50 mix of antifreeze and water. |
|
Engine
Mechanical
| Check for the following engine mechanical problems:
| • | Excessive oil in combustion chamber-Leaking valve seals. |
| • | Low cylinder compression. |
| • | Combustion chambers for excessive carbon buildup. Clean the combustion
chamber by using top engine cleaner. Follow the instructions on the can. |
| • | Check for incorrect basic engine parts. Inspect the following: |
| • | Refer to Engine Mechanical. |
|
Additional
Checks
|
|
