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Difficulty: MediumCausal Detail Extraction

Read the following technical passage about engine maintenance:

In turbocharged engines, improper shutdown procedures can cause severe damage through a process known as oil coking. When an engine is turned off immediately following high-load operation, the active circulation of oil and coolant ceases abruptly. However, immense residual heat from the exhaust manifold continues to soak into the turbocharger's center housing. Because the stationary oil inside the bearings is exposed to this extreme temperature, it undergoes thermal breakdown and bakes into abrasive carbon deposits. Consequently, these hardened deposits restrict internal oil passages, leading to bearing starvation and mechanical seizure.

Based on the causal relationships described in the passage, arrange the following events in the order of cause to final effect.

  1. 1Active circulation of oil and coolant ceases immediately upon shutdown.
  2. 2Residual exhaust heat soaks into the turbocharger's center housing.
  3. 3Stationary oil undergoes thermal breakdown and bakes into carbon deposits.
  4. 4Restricted internal oil passages cause bearing starvation and mechanical seizure.

Answer

The correct sequence from primary cause to ultimate effect is: cessation of oil and coolant circulation, followed by residual heat soaking into the center housing, leading to thermal breakdown of stationary oil into carbon deposits, and culminating in restricted oil passages that cause bearing starvation and seizure.
The correct sequence mirrors the explicit cause-and-effect progression described in the text: stopping fluid circulation initiates heat absorption into the housing, which causes stagnant oil to bake into carbon deposits, which in turn obstructs passages and causes bearing starvation.

Step-by-Step Solution

1
Identify the primary initiating action stated in the passage.
The text states that turning off the engine immediately causes active fluid circulation to cease abruptly.
This establishes the initial condition that permits subsequent thermal damage.
2
Trace the immediate physical consequence of stopping fluid circulation while the turbocharger is hot.
Residual heat from the exhaust manifold soaks into the center housing.
Without active coolant flow to carry heat away, the housing absorbs excess thermal energy.
3
Extract the direct effect of heat exposure on the trapped lubricant.
Stationary oil breaks down thermally into hard, abrasive carbon deposits.
The passage explicitly links the thermal breakdown of stagnant oil to extreme temperature exposure.
4
Determine the final consequence resulting from the accumulated deposits.
Hardened deposits block oil passages, causing bearing starvation and seizure.
The passage signals the end result with 'Consequently,' linking carbon build-up to final component failure.

Key Concept

Extracting explicitly stated multi-step causal chains and sequence of mechanisms from technical text.
Estimated Time:1m 0s
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Topics

Causal Detail Extraction

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