1978/01/30 Caterpillar

Valve Damage Can Be Caused By Short Intervals Of Engine Operation In Very Cold Temperatures{1105,1208}

Usage:

All Engines

According to field reports, some customers have had problems with damage to engine valve components during operation in very cold temperature conditions. These problems are the result of engine operation for short intervals, where the engine is started and stopped many times but does not run long enough to become completely warm.

During the interval of time that the engine operates at temperatures below normal, fuel and oil are not completely burned in the combustion chambers. This fuel and oil causes soft carbon deposits on the valve stems. Generally, these deposits do not cause problems because they are burned off during operation at normal engine temperatures. When the engine is started and stopped at short intervals, and the engine temperature is never up to normal, the carbon deposits become thicker until they prevent free operation of the valves. This can cause burnt valves, bent push rods, or other damage to valve components.

For this reason, any time the engine is started, the recommendation is to run the engine until the coolant temperature is 150°F (66°C) or higher. This will keep carbon deposits on the valve stems at a minimum.

In addition, operation of the engine until it is thoroughly warm will keep the other engine parts in better condition and generally extend the service life of the engine. Lubrication will be improved, with less acid and sludge in the oil. This will give longer service life for engine bearings, piston rings, and other parts.

Caterpillar Information System:

1978/01/23 Change In Design Of Engine Governor, Fuel Injection And Transfer Pump Groups, And Fuel Ratio Control Groups{1264,1278,1286}

1978/01/23 Design Of Governor Control Linkage Changed; Less Force Is Needed To Move The Accelerator Pedal{1265,1269}

1978/01/16 Improved Gasket Prevents Oil Leakage From The Governor{1264}

1978/01/16 Turbine Housing For Turbocharger Is Stronger{1052}

1978/01/16 New Turbine Housings Are The Replacement For Three Former Turbine Housings Used On Schwitzer Turbochargers{1052}

1978/01/16 Tolerance Added To Valve Clearance Specifications{1105,0374}

1978/01/16 Improved Front Pulley And Damper Groups Use New Damper Adapter With Larger Diameter Bolt Circle For Pulley Bolts{1205}

1978/01/09 Improved Water Shield For Exhaust Manifold{1067}

1978/01/09 Inner Member Of Caterpillar Coupling Must Be Restrained If The Connection To The Inner Member Is Removed{3252}

1978/01/09 5P8665 Cylinder Liner Puller Makes Liner Removal Easier And Faster{0621,1216}

1978/01/09 Improved Seal Used Between Impeller And Bearings On Water Pump Shaft{1361,1371}

1978/01/09 Service Tip: Use Caution When Hydraulically Operated Implements Must Be Lifted With A Hoist While The Engine Is Stopped{5050}

1978/01/30 Oil Strainer (Screen) Added To Turbocharger Thrust Bearing{1052,1053}

1978/01/30 New Water Pump Cover Has A Baffle And Wall To Send Coolant Flow From Bypass Line Directly Into Water Pump{1361}

1978/01/30 Stronger Front Support Assembly{1153}

1978/01/30 Do Not Change Factory Fuel Or Speed Settings On Truck Engines Unless New Settings Are Certified Under Applicable EPA Regulations{0336,0337,1257}

1978/02/06 Smaller Quantity Of Oil Now Used In Engine Oil Pan; Prevents Contact Between Crankshaft And Oil{1318}

1978/02/06 Successful Engine Service-3208 Engine Booklet Is Available{1000}

1978/02/06 Attachment Groups Put Corrosion Inhibitor Directly Into Cooling System{1350}

1978/02/06 New Water Temperature Regulator Opens At 180°F (82°C){1350,1355,7304}

1978/02/06 Probable Causes Of Low Fuel Delivery During Testing On Fuel Injection Test Benches{0650,1250}

1978/02/13 Replacement Seal Group For Water Pump Impeller Now Has All The Seal Parts Plus An Installation Tool{1361,0622}

1978/02/13 Complete Set Of Contact Points For Dial Indicators Is Now Available In One Group{0653}

1978/02/27 New Seal Assembly With Longer Ferrule Prevents Damage To Ferrule During Cylinder Head Installation{1100,1101,1300}