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ASE T2 Diesel Engines (Medium/Heavy Truck) study materials
ASE T2 Diesel Engines (Medium/Heavy Truck) study resources

ASE T2 Diesel Engines (Medium/Heavy Truck) practice questions

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Question 1Cylinder Head and Valve Train Diagnosis and Repair

A diesel engine cylinder head is being checked for warpage along the length of the deck. Which specification applies to the maximum allowable out-of-flatness?

  1. Camshaft lobe lift tolerance
  2. Manufacturer's service limit for longitudinal deck flatness Correct answer.
  3. Valve stem-to-guide clearance limit
  4. Head bolt torque-to-yield value

Explanation

Deck flatness is compared to the manufacturer's published service limit measured along and across the head with a straightedge and feeler gauge. Other specifications address different components and cannot substitute for a flatness limit.

Question 2Cylinder Head and Valve Train Diagnosis and Repair

During a valve clearance check on a mechanical diesel engine, the intake valve lash is found to be tighter than specification. What is the most likely consequence if it is not adjusted?

  1. The injector timing will advance by several degrees
  2. The valve may not seat fully, risking compression loss and burned valve faces Correct answer.
  3. The valve will open later and reduce cylinder pressure slightly
  4. The pushrod will run with excessive clearance and become noisy

Explanation

Too little lash holds the valve off its seat during the compression and power strokes, causing leakage, overheating, and possible valve face damage. Excess lash, by contrast, produces noise and reduced lift.

Question 3Cylinder Head and Valve Train Diagnosis and Repair

What is the primary purpose of a valve seat angle cut on the cylinder head?

  1. To center the valve guide in the head
  2. To increase valve spring installed height
  3. To provide a sealing surface that matches the valve face Correct answer.
  4. To reduce the valve stem diameter

Explanation

The seat angle is machined so the valve face contacts the seat on a narrow band, producing a reliable seal and heat transfer path. Spring height, guide centering, and stem diameter are controlled by other features.

Question 4Cylinder Head and Valve Train Diagnosis and Repair

A technician finds a bent pushrod on one cylinder of an overhead-valve diesel. Which condition is the most likely cause?

  1. A loose injector hold-down clamp
  2. A sticking valve or piston-to-valve contact Correct answer.
  3. A leaking head gasket coolant passage
  4. A worn valve guide clearance

Explanation

Pushrods bend when the valve train is forced against abnormal resistance, such as a seized valve or piston contact. Guide wear and coolant leaks do not load the pushrod in that manner.

Question 5Cylinder Head and Valve Train Diagnosis and Repair

Which component transfers motion from the camshaft lobe to the valve on a typical pushrod diesel engine?

  1. Injector rocker and nozzle
  2. Oil pump drive gear
  3. Timing belt and tensioner
  4. Rocker arm, pushrod, and lifter Correct answer.

Explanation

The cam lobe lifts the lifter, which pushes the pushrod, which actuates the rocker arm to open the valve. The other listed components perform unrelated functions.

Question 6Cylinder Head and Valve Train Diagnosis and Repair

A head bolt is specified as torque-to-yield. What does this mean for reuse?

  1. It may be reused if it is cleaned and oiled
  2. It may be reused only if it passes a thread pitch gauge check
  3. It must be replaced because it has been stretched beyond its elastic range Correct answer.
  4. It may be reused after being annealed

Explanation

Torque-to-yield bolts are tightened into plastic deformation, so they no longer provide reliable clamping and must be replaced. Cleaning or gauging does not restore the lost elastic properties.

Question 7Cylinder Head and Valve Train Diagnosis and Repair

What is the function of a valve guide in a diesel cylinder head?

  1. To seal combustion gases at the valve face
  2. To provide spring pressure for valve closing
  3. To maintain valve alignment and control oil to the stem Correct answer.
  4. To transfer heat from the valve head to the coolant jacket directly

Explanation

The guide keeps the valve stem aligned with the seat and meters oil to lubricate the stem. Combustion sealing is done by the valve face and seat, and spring force comes from the spring.

Question 8Cylinder Head and Valve Train Diagnosis and Repair

A compression test shows low pressure on one cylinder, and a wet test raises the reading substantially. Which area should be suspected first?

  1. Injector nozzle tip
  2. Piston rings and cylinder bore Correct answer.
  3. Head gasket coolant passage
  4. Intake valve seat

Explanation

Oil added during a wet test temporarily seals ring-to-bore leakage, raising compression. If the reading does not improve, valve or head gasket leakage is more likely.

Question 9Cylinder Head and Valve Train Diagnosis and Repair

A cylinder head is being inspected and a crack is found between the valve seats. Which repair approach is generally acceptable if the manufacturer permits it?

  1. Weld the crack without preheating the casting
  2. Ignore the crack if it is under 3 mm long
  3. Machine the seats deeper to remove the crack entirely
  4. Pin or stitch the crack and pressure test the head Correct answer.

Explanation

Manufacturer-approved crack repair typically involves pinning or stitching followed by a pressure test to verify sealing. Welding without proper procedure control or ignoring the crack risks failure.

Question 10Cylinder Head and Valve Train Diagnosis and Repair

A valve spring is being checked for squareness and free length. Why is installed spring height important?

  1. It controls the valve guide clearance
  2. It establishes the camshaft base circle diameter
  3. It sets the spring's installed force against the valve train Correct answer.
  4. It determines the valve seat angle

Explanation

Installed height determines the spring's preload force, which affects valve seating and valve float behavior. Seat angle, guide clearance, and cam base circle are independent dimensions.

Question 11Cylinder Head and Valve Train Diagnosis and Repair

During disassembly, a technician notes that the valve stem tips are worn unevenly. Which condition most likely contributes to this wear?

  1. Insufficient valve spring pressure
  2. A leaking exhaust manifold gasket
  3. Excessive valve lash or a worn rocker pad Correct answer.
  4. Low coolant concentration

Explanation

Worn stem tips usually result from repeated impact or sliding contact caused by excessive lash or a worn rocker arm pad. Spring pressure and gasket leaks affect different areas.

Question 12Cylinder Head and Valve Train Diagnosis and Repair

A head gasket has failed between two adjacent cylinders. Which symptom pattern is most consistent with this failure?

  1. Low oil pressure with no compression change
  2. Low compression on both cylinders with bubbles in the cooling system Correct answer.
  3. High fuel pressure with no compression change
  4. High compression on both cylinders with no coolant loss

Explanation

A breach between cylinders allows compression to escape into the neighboring cylinder and pressurizes the cooling system, producing low readings on both and bubbles in the coolant. Fuel or oil pressure symptoms do not match.

Question 13Cylinder Head and Valve Train Diagnosis and Repair

What is the correct procedure for checking valve recession after a valve job?

  1. Measure the pushrod length with a caliper
  2. Measure the valve stem height relative to the head deck against specification Correct answer.
  3. Measure the valve spring free length
  4. Measure the camshaft end play

Explanation

Valve recession or stem height is measured from the valve tip to the head deck and compared to specification to ensure the valve sits at the correct depth. The other measurements address different components.

Question 14Cylinder Head and Valve Train Diagnosis and Repair

A technician is setting valve lash on an engine with a specified adjustment sequence. Why must the sequence and engine position be followed?

  1. To maintain oil pressure during cranking
  2. To keep the injector from firing during adjustment
  3. To ensure each valve is on the base circle of its cam lobe when adjusted Correct answer.
  4. To prevent the turbocharger from overspeeding

Explanation

Lash must be set when the lifter is on the cam's base circle so the measured clearance reflects true lash. Following the sequence and positioning avoids adjusting on the ramp or nose of the lobe.

Question 15Cylinder Head and Valve Train Diagnosis and Repair

A cylinder head is being checked for valve guide wear. Which measurement method is most appropriate?

  1. Measure head bolt stretch with a straightedge
  2. Measure stem-to-guide clearance with a dial bore gauge and micrometer Correct answer.
  3. Measure valve spring installed height with a caliper
  4. Measure rocker arm ratio with a protractor

Explanation

Guide wear is evaluated by comparing the guide bore to the valve stem diameter, typically using a bore gauge and micrometer. The other tools measure unrelated dimensions.

Question 16Cylinder Head and Valve Train Diagnosis and Repair

An engine has a persistent miss and a leak-down test shows air escaping into the exhaust port on one cylinder. Which component is most likely at fault?

  1. Head gasket fire ring
  2. Piston ring lands
  3. Exhaust valve and seat Correct answer.
  4. Intake valve and seat

Explanation

Air escaping into the exhaust port during leak-down indicates leakage past the exhaust valve and seat. Intake leakage would escape into the intake, and ring leakage would escape into the crankcase.

Question 17Cylinder Head and Valve Train Diagnosis and Repair

A camshaft is being checked for wear. Which measurement best indicates a worn lobe?

  1. Lobe lift compared to specification Correct answer.
  2. Gear backlash compared to specification
  3. End play compared to specification
  4. Journal diameter compared to specification

Explanation

Lobe lift, measured as the difference between base circle and nose, directly indicates cam lobe wear. Journal diameter, end play, and gear backlash describe other camshaft characteristics.

Question 18Cylinder Head and Valve Train Diagnosis and Repair

Which condition would most likely cause valve float at high engine speed?

  1. An overfilled cooling system
  2. Excessive valve guide clearance
  3. Insufficient valve spring force relative to valve train mass Correct answer.
  4. A restricted fuel return line

Explanation

Valve float occurs when the spring cannot keep the follower in contact with the cam at high speed, typically due to insufficient spring force or excessive valve train mass. Guide clearance and fuel or cooling issues do not cause float.

Question 19Cylinder Head and Valve Train Diagnosis and Repair

A technician is preparing to install a cylinder head. What is the correct order for tightening the head bolts?

  1. Follow the manufacturer's torque sequence from the center outward in stages Correct answer.
  2. Tighten all bolts to full torque in a clockwise circle
  3. Tighten only the outer bolts first, then the inner bolts
  4. Tighten from the ends toward the center in one pass

Explanation

Head bolts are tightened in the specified sequence, usually from the center outward, in staged torque steps to distribute clamping force evenly. One-pass or outside-in tightening risks gasket distortion.

Question 20Cylinder Head and Valve Train Diagnosis and Repair

A cracked cylinder head is suspected near the injector sleeve. Which test is most useful to confirm a coolant-to-combustion leak at that location?

  1. Check fuel return flow volume
  2. Measure turbocharger boost pressure
  3. Pressurize the cooling system and inspect the injector bore for coolant Correct answer.
  4. Perform a cylinder balance test

Explanation

Pressurizing the cooling system and watching for coolant at the injector sleeve or bore confirms a breach between the coolant jacket and the injector area. Balance, fuel return, and boost tests evaluate different systems.

Question 21Cylinder Head and Valve Train Diagnosis and Repair

A valve seat has been replaced and machined. Which step verifies concentricity between the seat and the guide?

  1. Check the seat runout with a dial indicator referenced to the guide Correct answer.
  2. Measure the seat width with a caliper
  3. Check the spring installed height with a height gauge
  4. Measure the valve face margin with a micrometer

Explanation

Seat concentricity is verified by indicating the seat while referencing the valve guide, ensuring the valve seals evenly. Width, margin, and spring height describe other features.

Question 22Cylinder Head and Valve Train Diagnosis and Repair

An overhead-cam diesel head shows wear on the cam bearing journals and caps. Which factor most directly accelerates this wear?

  1. Excessive valve lash on the intake valves
  2. Loss of oil pressure or contaminated oil at the cam bearings Correct answer.
  3. A restricted air filter
  4. A loose exhaust manifold stud

Explanation

Cam bearing wear is driven primarily by lubrication failure or contamination, which allows metal-to-metal contact. Lash, air filtration, and exhaust hardware do not directly load the cam bearings.

Question 23Cylinder Head and Valve Train Diagnosis and Repair

A technician observes that a valve is not rotating on an engine equipped with valve rotators. Which condition is most likely responsible?

  1. A clogged fuel filter
  2. A worn or seized rotator mechanism Correct answer.
  3. Excess valve lash
  4. A leaking intake manifold gasket

Explanation

Valve rotators depend on a functioning mechanism to index the valve each cycle; seizure or wear stops rotation and can lead to uneven valve wear. Lash, intake leaks, and fuel filtration do not control rotation.

Question 24Cylinder Head and Valve Train Diagnosis and Repair

A cylinder head is being evaluated after an overheat event. Which inspection result most strongly indicates the head should be replaced rather than resurfaced?

  1. Minor oil staining on the exterior
  2. Deck warpage exceeding the manufacturer's maximum allowable material removal Correct answer.
  3. Light carbon deposits in the combustion chambers
  4. Normal valve stem heights within specification

Explanation

If warpage requires removing more material than the manufacturer allows, compression ratio and valve train geometry would be affected, so replacement is required. Cosmetic deposits and staining do not condemn a head.

Question 25Cylinder Head and Valve Train Diagnosis and Repair

A valve spring test shows a spring with reduced tension but correct free length. Which effect is most likely on engine operation?

  1. Reduced valve seating force and possible valve bounce at speed Correct answer.
  2. Increased valve guide clearance
  3. Advanced injection timing
  4. Higher compression pressure

Explanation

A spring that has lost tension cannot maintain proper seating force, allowing valve bounce or float and poor sealing at higher speeds. It does not alter injection timing, guide clearance, or raise compression.

Question 26Engine Block Diagnosis and Repair

A cylinder liner is being checked for out-of-round with an inside micrometer. Where should the measurement be taken to detect the greatest wear?

  1. At the top of the ring travel area, parallel to the crankshaft axis
  2. At the bottom of the liner, perpendicular to the crankshaft axis
  3. At mid-stroke, parallel to the crankshaft axis
  4. Just below the top ring reversal point, perpendicular to the crankshaft axis Correct answer.

Explanation

Maximum cylinder wear occurs just below the top ring reversal point where combustion pressure and ring loading are highest, and it develops perpendicular to the crankshaft axis because side thrust from the connecting rod pushes the piston against the liner in that direction. Measuring parallel to the crank or at the bottom understates the wear.

Question 27Engine Block Diagnosis and Repair

During a cylinder head removal, the technician finds coolant in the oil and bubbling in the radiator with the engine running. Which block condition most directly explains both symptoms?

  1. A restricted oil cooler bypass
  2. A cracked cylinder liner or block deck near a coolant passage Correct answer.
  3. Excessive crankshaft end play
  4. A worn camshaft bearing

Explanation

A crack or breach between a coolant passage and a cylinder or oil gallery allows combustion pressure to enter the cooling system (bubbling) and coolant to enter the crankcase (milky oil). Camshaft bearings, end play, and oil cooler bypass do not connect combustion gas to coolant.

Question 28Engine Block Diagnosis and Repair

A block is being checked for deck flatness with a straightedge and feeler gauge. What is the primary reason this check is performed?

  1. To check the camshaft bore alignment
  2. To verify the block can accept oversize main bearings
  3. To confirm the deck will seal the head gasket and that the liners sit at the correct height Correct answer.
  4. To measure the bore diameter for piston selection

Explanation

Deck flatness affects head gasket sealing, and any distortion also influences liner protrusion and clamping. Bearing size, bore diameter, and cam bore alignment are measured with different tools and procedures.

Question 29Engine Block Diagnosis and Repair

A wet-sleeve engine shows a liner protrusion of 0.001 in (0.025 mm) above the deck on one cylinder, while the specification calls for 0.003–0.005 in (0.076–0.127 mm). What is the most likely consequence if assembled as-is?

  1. Reduced liner-to-block contact and liner cracking
  2. Head gasket failure and possible coolant leakage into the cylinder Correct answer.
  3. Improved head gasket clamping and sealing
  4. Excessive piston-to-valve clearance

Explanation

Insufficient liner protrusion reduces the clamp load the head gasket applies to the liner flange, allowing combustion gas and coolant to migrate past the gasket. The correct fix is to check the counterbore and shim or machine as specified.

Question 30Engine Block Diagnosis and Repair

A technician is measuring main bearing bore alignment using a straightedge and checking for a twisted block. Which condition is being evaluated?

  1. Camshaft lobe lift
  2. Main bore alignment (saddle alignment) Correct answer.
  3. Connecting rod bend
  4. Crankshaft journal taper

Explanation

Main bore alignment checks whether all main saddles share a common centerline; a misaligned block causes uneven bearing wear and crankshaft binding. Lobe lift, journal taper, and rod bend are separate measurements.

Question 31Engine Block Diagnosis and Repair

A block is being hot-tank cleaned and inspected. After cleaning, the technician notices a hairline indication near a main bearing saddle. Which inspection method is best suited to confirm a surface crack in the cast iron?

  1. Magnetic particle inspection Correct answer.
  2. Brinell hardness testing
  3. Dial indicator runout check
  4. Ultrasonic thickness testing

Explanation

Magnetic particle inspection reveals surface and near-surface discontinuities in ferromagnetic materials like cast iron by the way particles collect at flux leakage. Ultrasonic thickness, hardness, and runout measure different properties.

Question 32Engine Block Diagnosis and Repair

A liner shows vertical scoring on the thrust side with metal transfer. Which of the following is the most probable cause?

  1. Low fuel pressure
  2. Incorrect valve lash
  3. Broken ring or foreign object in the cylinder Correct answer.
  4. Coolant contamination in the oil

Explanation

Vertical scoring with metal transfer indicates mechanical contact from a broken ring, piston damage, or debris trapped between piston and liner. Coolant contamination causes corrosion/polishing, and valve lash or fuel pressure do not score liners.

Question 33Engine Block Diagnosis and Repair

What is the purpose of a counterbore in a wet-sleeve engine block?

  1. To locate and support the liner flange and set liner protrusion Correct answer.
  2. To provide clearance for the crankshaft counterweights
  3. To retain the camshaft bearings
  4. To route coolant around the main bearings

Explanation

The counterbore is machined into the deck to seat the liner flange, establishing the liner's installed height and protrusion for proper head gasket sealing. It does not relate to counterweight clearance, coolant routing, or cam bearings.

Question 34Engine Block Diagnosis and Repair

A dry-sleeve block is being checked for bore wear. The technician measures the bore at the top, middle, and bottom in two planes. Why are two planes measured?

  1. To determine oil clearance
  2. To detect out-of-round and taper Correct answer.
  3. To check liner protrusion
  4. To measure deck height

Explanation

Measuring in two perpendicular planes at multiple heights reveals out-of-round and taper, the key wear indicators that determine whether boring or sleeving is needed. Oil clearance, deck height, and protrusion require other measurements.

Question 35Engine Block Diagnosis and Repair

A block has been magnafluxed and a crack is found in a water jacket between two cylinders. Which repair is generally acceptable for a cast iron block in a heavy-duty application?

  1. Fill with epoxy and reassemble
  2. Pin and stitch the crack per manufacturer procedure Correct answer.
  3. Leave it and monitor
  4. Weld with oxy-acetylene without preheat

Explanation

Crack stitching or pinning following the manufacturer's approved procedure is an accepted repair for non-structural jacket cracks in cast iron. Uncontrolled welding, epoxy fill, or ignoring the crack risks failure and coolant leakage.

Question 36Engine Block Diagnosis and Repair

After a block is line bored, the technician checks main bearing crush. What does proper bearing crush ensure?

  1. Correct oil clearance
  2. Proper piston deck clearance
  3. The bearing shell is held tightly in the saddle so it cannot move Correct answer.
  4. Correct crankshaft end play

Explanation

Crush is the interference fit created when the cap is torqued, forcing the shell against the saddle so it cannot shift or spin. Oil clearance, end play, and deck clearance are separate specifications.

Question 37Engine Block Diagnosis and Repair

A technician finds that a main bearing cap is numbered but installed in the wrong position. What is the most likely result?

  1. Misalignment of the main bore causing bearing and crank damage Correct answer.
  2. Higher fuel pressure
  3. Increased valve lash
  4. No effect if torque is correct

Explanation

Caps are matched and numbered to their saddles; swapping them misaligns the bore and causes uneven bearing loading, binding, and possible crank failure. Torque alone cannot correct a mismatched cap.

Question 38Engine Block Diagnosis and Repair

Which measurement best determines whether a cylinder can be honed to size or must be bored oversize?

  1. Maximum taper and out-of-round compared to the wear limit Correct answer.
  2. Deck flatness
  3. Crankshaft runout
  4. Liner protrusion

Explanation

Bore taper and out-of-round, compared to the manufacturer's wear limit, dictate whether honing restores the bore or an oversize bore is required. The other measurements address different block features.

Question 39Engine Block Diagnosis and Repair

A wet liner is being installed and the technician applies a light coat of soap solution to the O-rings. Why?

  1. To improve heat transfer
  2. To lubricate the seals so they do not roll or tear during installation Correct answer.
  3. To prevent corrosion
  4. To seal the liner to the block permanently

Explanation

A compatible lubricant (often soap solution) lets the O-rings slide past the bore without rolling, twisting, or tearing, which would cause coolant leaks. It is not a permanent sealant or corrosion treatment.

Question 40Engine Block Diagnosis and Repair

A block shows fretting and corrosion at the liner counterbore seat. What is the recommended corrective action?

  1. Machine the counterbore and use a shim to restore correct protrusion Correct answer.
  2. Install the liner with extra sealant
  3. Torque the head bolts higher
  4. Use a thicker head gasket

Explanation

Corrosion or fretting at the counterbore prevents the liner flange from seating squarely, so the counterbore must be machined and a shim used to restore the specified protrusion. Sealant, higher torque, or a thicker gasket do not correct the seat.

Question 41Engine Block Diagnosis and Repair

A technician is checking camshaft bore alignment in a block. Which tool is most appropriate?

  1. Cam bore alignment bar or line bore gauge Correct answer.
  2. Feeler gauge and straightedge
  3. Inside micrometer
  4. Torque wrench

Explanation

A cam bore alignment bar or line bore gauge checks whether all cam bores share a common centerline. An inside micrometer measures diameter, a straightedge checks flatness, and a torque wrench applies fastener load.

Question 42Engine Block Diagnosis and Repair

Which of the following best describes the function of the block deck?

  1. It supports the crankshaft main journals
  2. It houses the oil pump
  3. It retains the flywheel
  4. It provides the flat sealing surface for the cylinder head gasket Correct answer.

Explanation

The deck is the machined top surface of the block that seals against the head gasket and supports the liners or bores. Main journals, oil pump, and flywheel are supported by other block features.

Question 43Engine Block Diagnosis and Repair

A block is being evaluated after a severe overheat. Which condition is most likely to require block replacement rather than repair?

  1. A minor scratch in a cylinder bore
  2. A worn camshaft bearing
  3. A warped deck exceeding the maximum machining limit Correct answer.
  4. Slight surface rust on the deck

Explanation

If deck warpage exceeds the maximum amount that can be machined while maintaining specifications, the block cannot be salvaged. Surface rust, worn cam bearings, and minor bore scratches are repairable.

Question 44Engine Block Diagnosis and Repair

Why is a torque plate used when honing cylinders in a block?

  1. To measure bore taper
  2. To hold the block to the boring bar
  3. To align the camshaft
  4. To simulate head bolt clamping distortion so bores are round when assembled Correct answer.

Explanation

A torque plate duplicates the distortion caused by head bolt clamping so the bores are honed round in the assembled condition. It is not a fixture for the boring bar, a measuring tool, or a cam alignment device.

Question 45Engine Block Diagnosis and Repair

A technician observes that a cylinder liner has a polished, glazed appearance with no crosshatch. What is the appropriate action?

  1. Add oil additive
  2. Increase ring gap
  3. Deglaze or hone the liner to restore crosshatch Correct answer.
  4. Replace the piston only

Explanation

Glazing prevents rings from seating, so the bore must be deglazed or honed to restore the crosshatch that retains oil and promotes ring seating. Replacing only the piston, changing ring gap, or additives do not correct glazing.

Question 46Engine Block Diagnosis and Repair

During inspection, the technician finds that the block main bore is out of alignment by more than the service limit. What is the typical consequence if the engine is assembled without correction?

  1. Increased compression ratio
  2. Crankshaft binds and bearings wear unevenly Correct answer.
  3. Reduced valve lash
  4. Higher coolant pressure

Explanation

Misaligned main bores force the crankshaft out of its true centerline, causing binding, uneven bearing loading, and premature failure. Compression ratio, valve lash, and coolant pressure are not directly affected.

Question 47Engine Block Diagnosis and Repair

A block is being prepared for a rebuild and the technician notices the oil gallery plugs are removed. Why are gallery plugs removed during cleaning?

  1. To reduce block weight
  2. To allow cleaning and inspection of the oil galleries Correct answer.
  3. To install larger bearings
  4. To improve coolant flow

Explanation

Removing gallery plugs allows brushes and cleaning solution to reach internal oil passages, ensuring sludge and debris are removed before assembly. Weight, coolant flow, and bearing size are unrelated.

Question 48Engine Block Diagnosis and Repair

A technician is checking a block for a cracked main web using a dye penetrant method. What is the first step after cleaning the area?

  1. Inspect under UV light
  2. Apply penetrant and allow dwell time Correct answer.
  3. Apply cleaner/remover
  4. Apply developer

Explanation

Dye penetrant inspection requires applying penetrant and allowing it to dwell in discontinuities before removing excess and applying developer. Applying developer first or inspecting before development yields false results.

Question 49Engine Block Diagnosis and Repair

Which condition would most likely cause a liner to crack at the flange?

  1. Incorrect valve adjustment
  2. Excessive liner protrusion beyond specification Correct answer.
  3. Low oil pressure
  4. Insufficient head bolt torque

Explanation

Excessive protrusion concentrates clamping force at the flange, cracking the liner. Insufficient torque, valve adjustment, and oil pressure do not create the flange stress that cracks liners.

Question 50Engine Block Diagnosis and Repair

A technician is deciding whether to replace or reuse a main bearing cap bolt. Which factor is most important?

  1. Bolt color
  2. Bolt head markings
  3. Whether the bolt is torque-to-yield and has been stretched beyond spec Correct answer.
  4. Age of the engine

Explanation

Torque-to-yield bolts stretch permanently and must be measured or replaced per specification; reuse of a stretched bolt loses clamp load. Color, markings, and engine age alone are not reliable criteria.