Chart 9
- Spark Knock
NOTE:
Carbon build up in the combustion chamber and on the back of valves can be a contributing factor for engine spark knock concerns. Remove carbon deposits prior to any component replacements.
| SYSTEM/COMPONENT | REFERENCE (Engine Controls Pinpoint Test unless noted) |
|---|---|
| Cooling System | Verify the engine operates at normal temperature. REFER to the appropriate Engine Cooling article, The Engine Overheats or NO DIAGNOSTIC TROUBLE CODES (DTCS) PRESENT SYMPTOM CHART INDEX to diagnose any cooling system concerns that are present. Verify correct coolant level and coolant concentration. REFER to the Engine Cooling, Cooling System Draining, Filling and Bleeding article for correct coolant concentrations and fill procedures. |
| Mass Airflow (MAF) Sensor | GO to PINPOINT TEST DC . |
| Base Engine | REFER to the Engine System, Diagnosis And Testing article to continue diagnosis. |
| Fuel Delivery System | GO to PINPOINT TEST HC . |
| Secondary Ignition System | GO to PINPOINT TEST JB . |
| Positive Crankcase Ventilation (PCV) System | GO to PINPOINT TEST HG . |
| Engine Oil Quality | Visual. |
| Additional Testing | GO to PINPOINT TEST Z . |