Inspections and maintenance are vital in order to maintain engines (diesel and gasoline) in proper operating condition and to minimize the occurrence of casualties caused by material failure.

A comparatively minor engine malfunction, if not recognized and remedied in its early stages, might well develop into a major casualty. You and your work center personnel must be able to recognize the symptoms of any developing malfunction by using your senses of sight, hearing, smell, or even touch or feel (heat/vibration).

Your personnel must be trained to pay particular and continuous attention to the follow-ing indicators of oncoming malfunctions:

1. Unusual noises

2. Vibrations

3. Abnormal temperatures

4. Abnormal pressures

5. Abnormal operating speeds

All operating personnel should thoroughly familiarize themselves with the specific temperatures, pressures, and operating speeds of equipment that are required for normal operation, so that any departure from the normal will become more readily apparent.

If a gage, or other instrument for recording operating conditions of machinery, gives an abnormal reading, the cause of the malfunction must be fully investigated. Normally the installa-tion of a spare instrument, or a calibration test, will quickly indicate whether the abnormal reading is due to instrument error. Any other cause must be traced to its source.

Because of the safety factor commonly incor-porated in pumps and similar equipment, con-siderable loss of capacity can occur before any external evidence is apparent. Changes in the operating speeds (from those normal for the existing load) of pressure-governor-controlled equipment should be viewed with suspicion. Most variations from normal pressures, lubricating oil temperatures, and system pressures indicate either inefficient operation or poor condition of machinery.

When a material failure occurs in any unit, a prompt inspection should be made of all similar units to determine whether there is any danger that a similar failure might occur in other units. The cause of the failure must also be determined and corrected in order to avoid repeated failure of the same or similar components. Prompt inspection may eliminate a wave of repeated casualties. Strict attention must be paid to the proper lubrication of all equipment, including frequent inspection and sampling to ensure that the cor-rect quantity of the proper lubricant is in the unit.

It is good practice to make a daily check of samples of lubricating oil in all auxiliaries. Such samples should be allowed to stand long enough for any water to settle. When auxiliaries have been idle for several hours, particularly overnight, a sufficient sample to remove all settled water should be drained from the lowest part of the oil sump. Replenishment with fresh oil to the nor-mal level should be included in this routine.

The presence of saltwater in the oil can be detected by drawing off the settled water by means of a pipette and by running a standard chloride test. A sample of sufficient size for the test can be obtained by adding distilled water to the oil sample, shaking it vigorously, and then allowing the water to settle before draining off the test sam-ple. Because of its corrosive effects, saltwater in the lubricating oil is far more dangerous to a unit than is an equal amount of freshwater. Saltwater is particularly harmful to units containing oil-lubricated ball bearings.

The information given so far relates to the inspections that Enginemen make on operating engines (either diesel or gasoline). Since the Navy uses more diesel than gasoline engines the remainder of this chapter will deal with diesel engines and with the inspection and maintenance procedures that are required by the planned maintenance system (PMS) and the manufac-turers technical manuals.