Chapter 50 homework

If the aneroid device on a hydro mechanical Diesel engine has been tampered with, which of the following is more likely? A. Increase in black smoke emission B. Increase in white smoke emission C. Reduction in engine power D, increase engine

A. Increase in black smoke emission

When inspecting a cracked PDF core, there is evidence of scorched fuel in the substance. What should be done after replacing the DPF? A. Send a fuel sample off for testing B. Change the fuel filters C. Plugged charge air cooler D. Restricted charge air cooler

A. Send a fuel sample off for testing

Which of the following could result in abnormally high manifold boost on an engine with a VGT turbocharger? A. Sticking VGT vans ring B. Retarded injection timing C. Plugged charge air cooler D. Restriction DPF

A. Sticking VGF came ring

Technician A says that when EGR flow rates are high, the result may be excessively high exhaust temperatures. Technician B says that any time exhaust temperatures are excessively high, the cause must relate the breathing circuit downstream from the engine cylinder. Who is correct? A. Technician A only B. Technician B only C. Both A and B D. Neither A nor B

A. Technician A only

Which of the following is more likely cause of an engine hunting condition? A. Unbalanced fuel delivery by injection B. Damaged aneroid device C. Low CN valve of fuel D. Plugged air filter

A. Unbalanced fuel delivery

When is HD-OBD Currently scheduled for implementation? A. 2012 B.2014 C. 2016 D. 2018

B. 2014

What is a common cause of injector scuffing? A. Use of 1D diesel fuel B. Adding methyl hydrate to fuel tank C. Prolonged periods of high engine loading D. Running at excessive road speeds

B. Adding methyl hydrate to fuel tank

What is the most likely result of a Diesel engine with too much oil in the sump? A. Blue smoke emission B. Aerated engine oil C. Engine runaway D. Hard cranking

B. Aerated engine oil

A truck Diesel engine is emitting black, smoke especially under load. Which of the following should be performed first? A. Check inlet restriction on fuel auction side B. Check air filter inlet restriction C. Check for high exhaust back pressure D. Perform an engine overhead adjustment

B. Check air filter inlet restriction

A Diesel engine produces produces a vibration complaint. Which of the following would be more likely the cause? A. Oil level in pan at low mark on dipstick B. Dent in the vicious vibration damper C. Broken cylinder head bolt D. Advanced injection timing

B. Dent in the vicious vibration damper

Blue smoke emission from a truck Diesel engine is usually caused by: A. An oil leak B. Semi-combusted oil in the exhaust gas C. Over fueling D. Air starvation

B. Semi-combusted oil an in the exhaust gas

Technician A says that an engine malfunction on a Mack electronic engine manufactured between 2002 and 2010 can have up to 10 possible causes. Who is correct? A. Technician A only B. Technician B only C. Both A and B D. Neither A nor B

C. Both A and B

Technician A says that a low oil pressure reading can be caused by insufficient oil in the crankcase. Technician B says that a low oil pressure reading can be caused by excessive oil in the crankcase. Who is correct? A. Technician A only B. Technician B only C. Both A and B D. Neither A nor B

C. Both A and B ( insufficient oil leaks)

When troubleshooting the cause of low oil pressure readings on a dash gauge, which of the following should be done first? A. Rebuild the oil pump B. Replace the piston oil control rings C. Check with a mast gauge D. Reset the pressure relief valve

C. Check with a master gauge

All of the following can cause a low oil pressure condition EXCEPT: A. Fuel in lube B. Excessive main bearing clearance C. Oil pump relief valve stuck closed D. Excessive rocker shaft bushing clearance

C. Excessive rocker shaft bushing clearance

If a secondary fuel filter has been double Gasketed after replacement, which of the following is most likely? A. Improperly filtered fuel B. Engine runaway C. Fuel leakage at secondary filter D. Sucking air at secondary filter

C. Fuel leakage at secondary filter

Which of the following instruments is designated for testing the exhaust gas temperature in a Diesel engine? Digital multimeter B. Scan tool C. Pyrometer D. Thermistor

C. Thermistor

You are checking a boosted diesel air intake system for inlet restriction using restriction using a negative pressure gauge. Which of the following would be the typical maximum acceptable spec reading on the gauge. A. 10 inches Hg restriction B. 25 inches Hg restriction C. 10 inches H2O restriction D. 25 inches H2O restriction

D. 25 inches H2O restriction

Which of the following can cause abnormally high DPF intake temperatures? A. Restricted boost air heat exchanger B. High air filter inlet restriction C. High altitude operations D. Any of the above

D. Any of the above

If an engine is said to be emitting high NOx, what color would the exhaust gas emission be? A.blue B. White C. Black D. Clear

D. Clear

When injection timing is advanced in a truck Diesel engine, which of the following would NOT be true? A. Engine power is increased B. Fuel economy is improved C. Engine longevity is reduced D. Engine emissions are reduced

D. Engine emissions are reduced

Which of the following conditions would be the more likely source of a coolant in oil condition? A. Prolonged high load operations B. Prolonged low load operations C. Failure of coolant filter pad lock off ball D. Leaking fuel injector cup seal

D. Leaking fuel injector cup seal

How should a cylinder misfire be checked out on an electrically controlled, EUI fueled diesel engine? A. Sequentially short out each injector by cracking each high pressure pipe B.remove the exhaust manifold and check for smoke C. Mechanically hold hold the EUI rocker in its down position D. Use an EST to perform an electronic cylinder cutout test

D. Use an EST to perform an electronic cylinder cutout test

What color smoke is associated with Diesel engine start up in extreme cold weather conditions? A. Gray B. Black C. Blue D. White

D. White

If an is leaking coolant into its cylinders which of the following would most likely be true? A. Black smoke emission B. Green smoke emission C. Red smoke emission D. White smoke emission

D. White smoke emission