General Engine Diagnostics Flashcards Preview

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Flashcards in General Engine Diagnostics Deck (12):
1

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

Oil
Fuel contamination
Coolant
HUEI

2

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
2)dust
3)excessive crankcase pressure

3

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

4

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

5

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

6

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
3)bleed

7

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.

1)cylinder
2) low
3) full

1) engine oil
2) loading

1) turbo
2) air intake
3) excessive

8

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

9

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

10

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

11

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

12

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