When installing an engine cylinder head, technicians must follow a strict multi-step tightening sequence rather than torquing fasteners at random. Beginning at the center bolts and systematically working outward in a crisscross or spiral pattern distributes clamping pressure evenly across the mating surfaces. If outer bolts are fully torqued first, the head gasket cannot flatten uniformly, often pinching and creating microscopic gaps around the combustion chambers. This uneven stress leads to premature gasket failure, severe coolant leaks, and costly compression loss.
Which of the following best expresses the main idea of the passage?
- AGasket distortion in an engine can cause severe coolant leaks and loss of combustion chamber compression.
- BTightening outer cylinder fasteners before center fasteners prevents a head gasket from flattening uniformly.
- Following a prescribed fastener tightening sequence is essential for achieving even clamping pressure and preventing cylinder head gasket failure.Answer
- DAutomotive engine maintenance requires strict adherence to universal fastener torque specifications across all assemblies.
Answer
Following a prescribed fastener tightening sequence is essential for achieving even clamping pressure and preventing cylinder head gasket failure.
The statement emphasizing that following a prescribed tightening sequence is essential for achieving even clamping pressure and preventing cylinder head gasket failure encompasses the entire paragraph. Every sentence in the text provides technical context, procedural instructions, or consequences that reinforce this core claim.
Step-by-Step Solution
Key Concept
Distinguishing between the central controlling idea of a paragraph and specific supporting examples or consequences.
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