Oilers/Plant Tenders (HHC) Civil Service Practice Exam

The oil pressure gage of a diesel engine lubrication system shows a high reading. This may be due to _______

1. An oil leak

2. Oil gage out of adjustment

3. A faulty oil pump

4. Excessive oil temperature

The correct answer is: Oil gage out of adjustment

A high reading on the oil pressure gauge in a diesel engine lubrication system can indicate an issue with the oil gauge itself. If the gauge is out of adjustment, it may inaccurately display higher pressure readings than what actually exists in the system. Calibration errors or mechanical failures within the gauge can lead to misleading readings that do not reflect the true condition of the oil pressure. In contrast, a physical condition such as an oil leak would typically lead to a decline in oil pressure rather than a high reading, as oil would escape from the system. A faulty oil pump could cause insufficient oil pressure, rather than an excessive one, as a malfunctioning pump might not be able to circulate oil properly. Excessive oil temperature usually results in lower oil pressure due to oil thinning, thus causing less resistance in the lubrication system. Each of these conditions would not produce a high reading on the oil pressure gauge, reinforcing why the adjustment of the gauge itself is the most plausible explanation for the high reading observed.