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Flashcards in General Engine Diagnostics Deck (12):

The first step in checking the lubrication system is to check the ----- level.

Oil that is to thin may indicate _______. Oil that is milky may indicate _______ contamination

Very low oil levels can cause no start on engines equipped with_____ fuel system

Fuel contamination


Crankcase pressure indicates the amount of ------- passing by the piston rings into the crankcase.

A slight pressure in the crankcase is desirable to prevent the entrance of ------- .

A loss of engine oil through the breather tube,crankcase ventilator,or dipstick hole in the block are signs of -------.

1) cylinder gas
3)excessive crankcase pressure


The proper quantity and quality of fuel and air must be applied to the cylinder with the right amount of ------- and -------.

Air starvation can cause ------- in the cylinder and decreased -------.

Some causes of air starvation are -----,-----,-----,and -----.

1) fuel/heat
2)heat build up / power
3)restricted intake hoses and pipes,dirty air filter,excessive back pressure, high Alt operation


Cause of high crankcase pressure may be traced to excessive blow by due to -----, a hole or crack in ----,-----,----,.

Check crankcase pressure with a ----- connected to the oil level dipstick opening in the block at various engine speeds.

Since ----- nearly all new engines have had a ----- ventilation system.
This separates the ------ and returns it to the oil pan.

1) worn piston rings / piston crown / cylinder head gasket / exhaust back pressure

2) Manometer

3)2007 / closed / oil vapor


No crank condition can be cause by -----,-----,or ----- that prevents cranking.

Some ECM programming will not allow engine cranking for ----- mins if it has just been cranked for longer than 30 secs.

Some ECM programming will not allow cranking for a hour if the exhaust system has just experienced extreme .

1) discharged batteries
2) poor electrical connection
3) ECM programming

1) two

1) overheating


When a Diesel engine cranks but does not start check the ----- to ensure that the engine is being fueled.

------ in the fuel is often the cause when an engine cranks but fails to start.

If air is the problem ------ the system using a ----- and ----- the lines to each injector while cranking the engine.

1) exhaust

1) air

1) pressurize
2)hand primer


A Diesel engine may not start or be hard to start because of the temp of the air in the ----- is to----- for ----- combustion of the atomized fuel.

The engine can offer to large of a load on the starter when ----- is to thick or the engine surfaces are to cold,or the belt or gear driven devices are ------ down the engine.

A defective----- or a restricted ----- or ------ back pressure will delay or prevent combustion pressure build up.

2) low
3) full

1) engine oil
2) loading

1) turbo
2) air intake
3) excessive


Diesel engine surging rough operation and misfire can be caused by poor----- , poor fuel -----, dirty or sticking injectors.

Low power and slow acceleration are usually caused by -----,-----,or -----.

Slow deceleration can be caused by restricted ------, or -----.

1) fuel quality / delivery
2)insufficient fuel / insufficient air /poor fuel quality
3) restricted fuel return lines / air in the fuel


Fuel starvation will generally result in ----- of fuel supplied with a ----- no noticeable change in ----- and low cylinder temperatures.

Some reasons for fuel starvation are ----- ,------ ,------, -----, or -----.

------- or improper spray patterns can reduce power and cause erratic
Operation usually with ----- or ----- smoke.

1) total combustion / loss of power / exhaust color
2) empty tank / fuel pump / fuel leaks / restricted filters / crimped fuel lines
3) faulty injectors / black / gray


Late injection timing can cause ----- smoke.

Overly lean combustion chamber can cause ------ smoke.

Overly rich combustion chamber can cause ----- or ------ smoke.

Rich combustion chamber can be caused by -----,-----, -----.

One major cause of black smoke is -----.

1) white
2) white
3) engine overload / insufficient fuel spray penetration / poor fuel evaporation due to advanced timing
4) air starvation


Over concentration of coolant additives can cause ----- and ----- and resulting in engine overheating.

Operating a Diesel engine with low concentration of coolant additives will result in pitting of ------, and excessive ----- and ----- build up.

Some coolant fans use a ------ clutch while others are ----- controlled and ------ loaded.

1) water pump leaks/ restricted coolant flow
2) pitting / rust / scale
3)viscous / air / spring


ECM will operate the cooling fan based upon ------, ------, ------ or engine braking request.

Coolant contaminated by fuel is often caused by ------ in the cylinder head.

Oil contamination of coolant will usually be caused by leaking ----- or -----.

1) coolant temp / intake air temp / ac system demand
2) faulty injector sleeves
3) head gasket / oil cooler