A diesel engine fails to start, even though...

Question 1 / 270705eccefa3bacbc34ba4d47dd7

Question 1 of 270705eccefa3bacbc34ba4d47dd7

A diesel engine fails to start, even though it can be barred over, but not cranked over. The probable cause is __________.

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Question 1 of 27070

A diesel engine fails to start, even though it can be barred over, but not cranked over. The probable cause is __________.

🔍 Key Concepts

• Difference between "barred over" manually and "cranked over" on starting air or electric starter • What a seized piston or bad bearing would feel like when you try to turn the engine by hand • How an air start system works and what happens if air cannot get to the starting motor or starting valves

💭 Think About

• If the engine can be turned by hand with a bar, what does that tell you about the internal mechanical condition of pistons and bearings? • Which of the listed problems would completely prevent the starter from being able to rotate the engine, even though it is free to turn mechanically? • Which option is most directly related to the starting system rather than the internal engine condition?

✅ Before You Answer

• Confirm that "seized" or badly fitted internal parts usually make the engine hard or impossible to bar over • Think about whether insufficient compression would stop the crankshaft from rotating, or just make it fail to fire • Consider how a closed/blocked starting air line or valve would affect the starter’s ability to turn the engine, even if the engine itself turns freely by hand

Question 1 of 27070

A diesel engine fails to start, even though it can be barred over, but not cranked over. The probable cause is __________.

a seized piston

an improperly fitted bearing

a closed or obstructed air starting line valve

insufficient compression

Question 1 / 270705eccefa3bacbc34ba4d47dd7

Question 1 of 270705eccefa3bacbc34ba4d47dd7

A diesel engine fails to start, even though it can be barred over, but not cranked over. The probable cause is __________.

Back

Question 1 of 27070

A diesel engine fails to start, even though it can be barred over, but not cranked over. The probable cause is __________.