ASE A1 Engine RepairCylinder Head and Valve TrainEasy
A technician is inspecting a cylinder head for warpage after an engine overheat event. The service manual specifies a maximum allowable warpage of 0.002 inches. The technician uses a straightedge and a feeler gauge to measure the cylinder head surface. If the feeler gauge slides under the straightedge at a specific point, what is the maximum thickness of feeler gauge that would still be considered acceptable if the straightedge is placed diagonally across the head?
- A0.003 inches.
- B0.002 inches.
- C0.004 inches.
- D0.001 inches.
Show answer & explanationAnswer & explanation
Correct answer: B. 0.002 inches.
The maximum allowable warpage is specified as 0.002 inches. Therefore, any feeler gauge that measures 0.002 inches or less that slides under the straightedge would be considered acceptable, as it does not exceed the specified limit.
Why the other options are wrong
- A. 0.003 inches exceeds the maximum allowable warpage of 0.002 inches, making it unacceptable.
- C. 0.004 inches greatly exceeds the maximum allowable warpage of 0.002 inches, making it unacceptable.
- D. 0.001 inches is less than the maximum allowable warpage, so it would be acceptable.
Cylinder Head Warpage
The distortion or unevenness of the cylinder head's sealing surface, often caused by overheating, which can lead to head gasket leaks.
- Measured with a straightedge and feeler gauge.
- Caused by thermal stress or improper torquing.
- Exceeding specifications requires machining or replacement.
Memory trick: If the gauge fits, but not too fat, the head is good, or close to that.