Maintenance & Troubleshooting for Portable and Standby Diesel Generators

Oil Changes & Valve Adjustments

Service for the generator set is much like the service you perform on your automobile. The generator set should have oil and all filters changed on a regular basis The generator should be kept free from dust and occasionally connections should be checked for looseness. These procedures are normally done every 100 hours or 3 months whatever comes first as suggested by our maintenance schedules. Severe weather patterns can increase the maintenance requirements, i.e., excessive dust, heat, moisture. Also any commercial type use or prolonged usage. The unit should also be checked from an electrical standpoint to be sure that it is performing as it was designed.

Oil Changes

Engine oil has limited life - after a certain point it starts losing lubricating qualities and carbonizes. Once it happens, the engine gets contaminated with carbon deposits or sludge that significantly shorten engine's life. When you change oil at or before manufacturer suggested interval, you change the oil before this "carbonizing" point, engine remains clean and once refilled with new oil ready to work hard again. If the engine oil has not been changed for long, carbon deposits start clogging the oil pickup screen decreasing oil supply and increasing friction. Compression decreases and engine start wearing much faster.

You must remove the oil filter and clean it when you perform your oil changes. It is normal at the first oil change to find lots of deposits and shavings on it. It will wash away with diesel fuel. Careful attention should be given to replacing the oil filter. There is an o-ring on it that can easily be pinched if you do not put some oil on it before squeezing it back into place. The oil filter must be fitted into the engine and the oil filter inserted all the way in or it will not make a proper seal inside resulting in low oil pressure readings.

Your first oil change is required at 25 hours and then very 100 hours or 3 month depending on what comes first. Even if you do not use your generator you should still change the oil as it breaks down and collects moisture. If you are using your generator for long periods of time or in very hot climates then it will be necessary to chage the oil more often. Synthetic DIESEL Motor Oil should be used. NOT Gas Engine Motor Oil. 15w40 for DIESEL ENGINES is required. High quality oil and regular oil changes are the key to longer engine life and coolar operation. Unlike your car, these diesel engines work a lot harder and faster and oil really makes a big difference on how long they will last.

After the initial break in period we recommend switching to synthetic oil. Synthetic oil can withstand higher temperature and can work longer without losing its lubricating qualities. It doesn't get thicker at below-zero temperatures providing good engine lubrication at a cold start. After your generators first oil change and initial break in period a good quality synthetic oil designed for diesel engines is recommended. Mobil1 is one of the best ones you can get however make sure what you buy is specifically for a diesel engine, there is a difference.

Procedure

• Place a pan under engine near the drain plug. (Silent Diesel Generators the oil will spill on the bottom of the frame and out of the trench below it)
• Remove the oil filter and wash with soap and water or use diesel fuel.
• Replace oil filter and oil drain plug and refill with synthetic 15w40 diesel oil to level shown.

Valve Adjustment

Adjustment of the intake and exhaust valve head clearance governs the performance of the engine, and must be performed accurately. The intake and exhaust valve head clearance must be checked and readjusted on a regular basis. It is critical to do your first adjustmet at 25 hours. After that time every 300 hours is acceptable. Failure to adjust the valves may result in engine damage that will not be covered under warranty. Valves that are out of adjustment may result in valve adjustment screws breaking and internal engine damage. Valves that are out of adjustment often cause overheating, and combustion problems that may show as black smoke when running for example.

 

Remove the valve rocker arm cover. Careful not to damage the gasket under it. Crank or rotate the engine and set the piston to top dead center (TDC) on the compression stroke. [when both the intake and exhaust valve rocker arms are "loose" it is the compression stroke.] Check and adjust the intake and exhaust valve head clearance. Loosen the lock nut and insert the feeler gauge, adjust the "valve adjustment screw" until the you feel a slight drag on the feeler gauge. The gap shoud be 0.15 mm - 0.2 mm

 

Set Gap Between Valve Spring and Rocker Arm The idea is to measure the gap accurately, if it is too loose or if the feeler is squeezed too tight, forcing the valve to open slightly against the force of the valve spring, the reading will not be accurate. With the feeler in place, hold the screw adjuster in place while tightening the jam nut. Recheck the clearance to make sure it did not move when tightening the jam nut.