🔍 Key Concepts

• Exhaust smoke color and engine condition (black vs blue vs white) • How fuel timing and combustion temperature affect exhaust appearance • Common symptoms of coolant or water entering the cylinder

💭 Think About

• Think about what happens inside the cylinder if fuel does NOT burn completely or burns too late—how would that look at the exhaust? • Which of these problems is most likely to let water or coolant get into the combustion space and then turn into white vapor? • Which symptom (black, blue, or white smoke) is usually linked to lube oil burning from worn rings?

✅ Before You Answer

• Match smoke color to cause: black = incomplete combustion (too much fuel/too little air), blue = burning lube oil, white = unburned fuel mist or water vapor. • Ask: which option directly involves a path for water/coolant into the cylinder? • Ask: which option would more likely cause blue smoke rather than white, due to oil burning?