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 ( PINPOINT TESTS unless noted) |
|---|---|
| Verify the engine operates at normal temperature | Visual. 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 appropriate Engine Cooling article, Cooling System Draining, Filling and Bleeding for correct coolant concentrations and fill procedures. |
| Mass Airflow (MAF) Sensor | GO to PINPOINT TEST DC . |
| Base Engine | REFER to the appropriate Engine System - General Information article and CARRY OUT the Inspection and Verification to continue diagnosis. |
| Fuel Delivery System | GO to PINPOINT TEST HC . |
| Secondary Ignition System | For vehicles equipped with a coil pack ignition system, GO to PINPOINT TEST JC
. For all others, 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 . |