🔍 Key Concepts

• Diesel engine breathing – how air in/exhaust out affects combustion • Back pressure in the exhaust system and its impact on engine operation • Relationship between restricted flow and heat buildup

💭 Think About

• If exhaust gases cannot get out easily, what happens to the pressure and temperature in the exhaust manifold? • Would a restriction in the exhaust make the engine run faster, slower, or work harder to push out gases? • Think about whether any real engine problem would result in no effect on performance when a major passage is clogged.

✅ Before You Answer

• Eliminate any choice that suggests no change when a key system is partially blocked • Consider which option matches a condition where the engine is working harder to push gases out against higher back pressure • Ask: which effect is most directly linked to hot, trapped exhaust gases in a restricted pipe or manifold?