Detonation/Preignition Not Caused By Ignition/Engine Conditions

1. Check engine coolant freeze point. If the tester does not register a reading, or if the reading is below 50° F, inspect ethylene-glycol/water ratio. A 100 percent solution of ethylene-glycol in the system causes the engine to run hotter and partially overheat.
^ Adjust the coolant solution to 50/50 water ethylene-glycol mixture.
^ If 100 percent ethylene-glycol solution is found in system, clean and flush system before replacing with 50/50 mixture of ethylene-glycol and water.