ENGINEMAN  1  &  C 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. COMPRESSION AND FIRING PRESSURES Readings   of   the   compression   and   firing pressures  must  be  taken  every  200  hours  for  the trend analysis graphs. They may also be taken at other  times  when  engine  operating  conditions require additional monitoring such as when an engine misfires, fires erratically, or when any one cylinder misfires regularly. There can be many reasons for an engine to misfire, some of these are a clogged air cleaner/filter, an engaged fuel 3-2