What does it mean if the exhaust stops producing water, and what are the consequences of ignoring this?

A. Water from the exhaust is only present in cold conditions — no water in warm weather is normal

B. No water from exhaust = raw water cooling failure. If ignored: the engine overheats within minutes; the impeller burns out; rubber cooling hoses soften and collapse; in severe cases the engine seizes. Stop the engine immediately and investigate the raw water circuit

C. White steam from the exhaust means the engine is overheating — water in the exhaust is not relevant

D. A slight reduction in exhaust water is normal at high revs — only act if the water stops completely for more than 10 minutes

A. Compression ignition: diesel fuel is ignited by the heat of highly compressed air (compression ratio ~22:1) — no spark plugs are used. Fuel is injected into the compressed air at the moment of ignition

B. Diesel engines work at lower compression ratios than petrol engines for safety

C. Diesel engines use spark plugs but fire in a different sequence to petrol engines

D. Diesel engines use carburettors to mix fuel and air before compression

A. Compression, ignition, induction, exhaust — the compression happens before air enters

B. Induction (air in): piston down, air drawn into cylinder. Compression: piston up, air compressed to high temperature. Power (ignition): fuel injected, combustion drives piston down. Exhaust: piston up, exhaust gases expelled

C. Ignition, compression, induction, exhaust

D. Induction, power, compression, exhaust