TM 5-3895-383-24
The temperature of an exhaust manifold port can
be an indication of a cylinder that has air being
delivered to it. Check the exhaust manifold
temperatures and compare the results. A lower
than normal cylinder temperature indicates that the
cylinder may be receiving air from the injector.
The color of the exhaust smoke can also indicate
which cylinder has a combustion leak. Move each
injector (one at a time) to the "FUEL ON" position
momentarily while checking the color of the exhaust
smoke. The cylinder that has air will produce
smoke that is gray or white in color.
Problem 23: Too Much Exhaust Smoke At Normal
Operating Temperatures (White/Black Or Blue
Smoke)
White Smoke (Go to Step 1)
Probable Cause(s):
Cold Outside Temperature
Long Idle Periods
Low Quality Fuel
Air In Fuel System
Water In Fuel System
Air Inlet Heater (if equipped) Not Operating
Properly
Valve Adjustment Not Correct
Fuel Injection Timing Not Correct
Misfiring Cylinder(s)
Intake/Exhaust Valves Or Piston Rings Leak
Compression
Defective Fuel Injector(s)
Black Smoke (Go to Step 12)
Fuel Injection Timing Retarded
Defective Fuel Injector(s)
FRC Setting Too Rich
Inlet Or Exhaust Air Leakage Or Restriction
Defective Turbocharger
Blue Smoke (Go to Step 17)
Oil Level In Engine Too High
Failure Of Turbocharger Oil Seal
Worn Valve Guides
Worn Piston Rings And/Or Cylinder Wall(s)
Wear Or Damage To Pistons
1.
Gold outside temperatures:
When the air outside is cold, the cylinder
temperature is cooler. Not all the fuel will burn in
the cylinders. The fuel which does not bum comes
out the exhaust as white smoke. White smoke is
normal in cold temperatures until the engine
operates long enough to become warm. There will
be less white smoke if No. 1 diesel fuel is used.
2.
Long idle periods:
When an engine runs at idle speed for a long period
of time, the cylinders cool and all of the fuel does
not burn. Do not idle an engine for a long period of
time. Stop an engine when it is not in use. If long
idle periods are necessary, use No. 1 diesel fuel.
3.
Low quality fuel:
Test
the
engine
using
fuel
according
to
recommendations by Caterpillar Inc.
4.
Air in fuel system:
With air in the fuel system the engine will normally
be difficult to start, run rough and release a large
amount of white smoke. Find the air leak in the fuel
system and correct it. If air is in the system, it will
generally get in on the suction side of the fuel
transfer pump. Refer to Problem No. 39, Air In
Fuel.
5.
Water in fuel system:
Water in the fuel system can result in low engine
compression. Check injection cup or head gasket
for water leak.
6.
Air Inlet Heater (if equipped) Not Operating Properly:
Refer to Problem 37: Air Inlet Heater (If Equipped)
in the Troubleshooting Section of the Service
Manual.
7.
Valve adjustment not correct:
Check and make necessary adjustments as per
Testing and Adjusting Section of the Service
Manual.
8.
Fuel injection timing not correct:
Check and make necessary adjustments as per
Testing and Adjusting Section of the Service
Manual.
6-45
