Chart 9
- Spark Knock
| SYSTEM/COMPONENT | REFERENCE (PINPOINT TESTS -- GASOLINE MODELS unless noted) |
|---|---|
| Verify the engine operates at normal temperature | Visual. REFER to the appropriate ENGINE COOLING article or STEP 2: 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 for proper coolant concentrations and fill procedures. |
| MAF Sensor | GO to Pinpoint Test DC . |
| Base Engine | REFER to the appropriate ENGINE article . |
| 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 . |
| PCV System | GO to Pinpoint Test HG . |
| Engine Oil Quality | Visual |
| Additional Testing | GO to Pinpoint Test Z . |