On a four-valve diesel head, each pair of valves is opened by one rocker arm through an adjustable valve bridge (crosshead) that rides on a guide pin. Why is each bridge adjusted before the valve clearance is set?

So both valves of the pair open and close together

So the guide pin, not the valves, takes the rocker load

So each valve spring sits at its installed height

So the clearance can be read at either valve stem

A new injector sleeve has been installed in a diesel cylinder head. Which check confirms that the new sleeve has put the injector nozzle where the manufacturer specifies?

A dial indicator check of tip protrusion

The torque on the injector hold-down clamp

A pressure test of the head's coolant passages

A cranking compression test on that cylinder

After a cylinder head is installed on a diesel and the valves and injectors are adjusted, the manufacturer's procedure calls for barring the crankshaft through two full turns by hand before the engine is cranked. What is this check for?

That no piston strikes a valve or nozzle tip

That oil has reached every rocker arm

That the head gasket seats before final torque

That the fuel system is primed to the injectors

On an overhead-camshaft diesel, a dial indicator on the nose of the camshaft shows end play over the manufacturer's maximum when the camshaft is pried fully rearward and then forward. Which part controls this end play?

The camshaft thrust plate or flange

The camshaft journal bearing shells

The camshaft drive gear's backlash

ASE T2 Cylinder Head & Valve Train Practice Questions

Five free practice questions on cylinder head and valve train: content area B of the ASE T2 Diesel Engines test, 4 of its 55 scored questions (7.3%). They are in the ASE format: four options, one best answer. Answer each one before opening the explanation. No account, no email.

01The questions

Recall · Cylinder Head and Valve Train Diagnosis and Repair

On a four-valve diesel head, each pair of valves is opened by one rocker arm through an adjustable valve bridge (crosshead) that rides on a guide pin. Why is each bridge adjusted before the valve clearance is set?
1. So the guide pin, not the valves, takes the rocker load
2. So both valves of the pair open and close together
3. So each valve spring sits at its installed height
4. So the clearance can be read at either valve stem
Show the answer

B. Correct. The rocker pushes on the center of the bridge, so the bridge must touch both valve stems at once; if one end sits high, that valve opens late and the bridge cocks on its guide pin. With the bridge level, the clearance measured between the rocker and the bridge is the true clearance for both valves.

Why not the others

A. The guide pin only keeps the bridge aligned; the rocker's push goes through the bridge into both valve stems. The bridge is adjusted so it bears on both stems evenly, which lets both valves open together.

C. Installed spring height is set by the valve, seat and spring seat dimensions (and any spring shim), not by the bridge. The bridge is adjusted so it touches both stems at once and both valves open together.

D. Valve clearance on a bridged pair is measured between the rocker arm and the top of the bridge, not at a valve stem. Adjusting the bridge first makes it bear on both stems so that one clearance is right for both valves.

ID T2-B-002 · Task T2-B-6 (ASE task list)
Recall · Cylinder Head and Valve Train Diagnosis and Repair

A new injector sleeve has been installed in a diesel cylinder head. Which check confirms that the new sleeve has put the injector nozzle where the manufacturer specifies?
1. The torque on the injector hold-down clamp
2. A pressure test of the head's coolant passages
3. A cranking compression test on that cylinder
4. A dial indicator check of tip protrusion
Show the answer

D. Correct. How deep the sleeve seats, and the seat it gives the injector, sets how far the nozzle tip stands out past the fire deck, which places the spray where the piston bowl expects it. Protrusion is read with a dial indicator zeroed on the deck and compared with the manufacturer's range.

Why not the others

A. The hold-down torque clamps the injector onto its seat; it does not set how far the tip stands out, which depends on how the sleeve and seat are positioned. Protrusion is measured with a dial indicator against the manufacturer's range.

B. A pressure test shows whether the new sleeve seals coolant out of the injector bore, which is also needed after a sleeve job, but it says nothing about where the nozzle tip sits. Tip height is checked by measuring protrusion with a dial indicator.

C. Compression shows how well the rings, valves and gasket hold pressure; it cannot show whether the nozzle stands too far into or too far back from the chamber. Nozzle height is measured as tip protrusion with a dial indicator.

ID T2-B-004 · Task T2-B-5 (ASE task list)
Tech ab · Cylinder Head and Valve Train Diagnosis and Repair

A warped diesel cylinder head has had its deck resurfaced. Technician A says each valve head will now sit less far below the deck than it did before. Technician B says the injector nozzle tips will now protrude less past the deck than before. Who is right?
1. A only
2. B only
3. Both A and B
4. Neither A nor B
Show the answer

A. Correct. Technician A is right: machining removes metal from the deck face while the valve seats stay where they are, so each valve head ends up closer to the deck. Technician B is wrong: the injector seats do not move either, so the tips stand farther past the new deck, and both valve depth and protrusion are rechecked against the manufacturer's limits.

Why not the others

B. Only Technician A is right. Technician B has the effect reversed: with deck metal removed and the injector seats unchanged, the nozzle tips protrude more, not less. Technician A's point holds: the valve heads now sit closer to the deck.

C. Only Technician A is right. Resurfacing does bring the valve heads closer to the deck, as A says, but Technician B is wrong because the same loss of deck metal makes the nozzle tips protrude more, not less.

D. Technician A is right: removing deck metal leaves the valves closer to the deck. Technician B is the one who is wrong, because the nozzle tips end up protruding farther past the machined deck.

ID T2-B-006 · Task T2-B-3 (ASE task list)
Recall · Cylinder Head and Valve Train Diagnosis and Repair

After a cylinder head is installed on a diesel and the valves and injectors are adjusted, the manufacturer's procedure calls for barring the crankshaft through two full turns by hand before the engine is cranked. What is this check for?
1. That oil has reached every rocker arm
2. That no piston strikes a valve or nozzle tip
3. That the head gasket seats before final torque
4. That the fuel system is primed to the injectors
Show the answer

B. Correct. Turning the engine slowly by hand lets the technician feel any valve, nozzle tip or trapped liquid stop a piston before the starter could bend or break parts. Two turns take every cylinder through its full cycle, so every valve opening is checked.

Why not the others

A. Barring the engine by hand turns the oil pump far too slowly to build pressure or send oil to the rockers; prelubrication, where the manufacturer calls for it, is done another way. The hand turns are a check that nothing strikes a piston.

C. The head bolts are brought to final torque in the manufacturer's sequence before the valves are adjusted, so the gasket is already clamped. Barring the engine over is a check that no valve or nozzle tip contacts a piston.

D. Fuel is primed with the priming pump or the manufacturer's priming procedure, not by turning the crankshaft by hand. The two hand turns are made to confirm that the pistons clear every valve and nozzle tip.

ID T2-B-008 · Task T2-B-7 (ASE task list)
Recall · Cylinder Head and Valve Train Diagnosis and Repair

On an overhead-camshaft diesel, a dial indicator on the nose of the camshaft shows end play over the manufacturer's maximum when the camshaft is pried fully rearward and then forward. Which part controls this end play?
1. The rocker arm shaft bushings
2. The camshaft journal bearing shells
3. The camshaft drive gear's backlash
4. The camshaft thrust plate or flange
Show the answer

D. Correct. End play is the camshaft's fore-and-aft movement, and it is limited by the thrust surfaces, a thrust plate or flanged thrust bearing, against which the camshaft rides. When end play is over the limit, those thrust surfaces are worn and are replaced, then end play is measured again.

Why not the others

A. Rocker shaft bushings set the rocker arms' clearance on their shaft and do not hold the camshaft lengthwise. End play is controlled by the camshaft's thrust plate or thrust flanges.

B. The journal bearings set the camshaft's radial (oil) clearance, how far it can move up and down in its bores, not how far it slides lengthwise. Lengthwise movement is limited by the thrust plate or flanges.

C. Backlash is the rotational free play between the cam gear and the gear driving it, measured separately with a dial indicator on a gear tooth. Fore-and-aft camshaft movement is limited by the thrust surfaces.

ID T2-B-010 · Task T2-B-11 (ASE task list)

02Answer key

Question	Answer
Q1	B
Q2	D
Q3	A
Q4	B
Q5	D

03What area B covers

This content area covers the cylinder head and valve train on a truck diesel: removing, cleaning and inspecting the head, its bolts and threaded holes, deck flatness and thickness, valves, seats, springs and rotators, injector sleeves and nozzle protrusion, valve bridges, rocker arms and push tubes, cam followers, overhead camshafts and their end play, and setting valve clearance and injector adjustment.

The ASE test specification calls this content area “Cylinder Head and Valve Train Diagnosis and Repair”. It carries 4 of the 55 scored questions, 7.3% of the test.

Remove, clean and inspect the cylinder head
Check head bolts, studs and threaded holes
Measure deck warpage, thickness and surface finish
Inspect valves, seats, springs, rotators and seals
Replace injector sleeves and check nozzle protrusion
Service valve bridges, rockers, push tubes and followers
Measure overhead camshaft end play and backlash
Set valve clearance and injector adjustment

04What the questions turn on

Finding TDC on compression

On an inline six the pistons move in pairs: 1 and 6, 2 and 5, 3 and 4. When one cylinder of a pair is at TDC on valve overlap, its partner is at TDC on compression with both valves closed.

Resurfacing moves the deck

Machining the deck removes metal while the valve seats and injector seats stay where they were. Valve heads end up closer to the deck and nozzle tips stand farther past it, so valve depth and tip protrusion are measured again.

Look below the push tube

Extra clearance on one valve, with a straight push tube and an unworn rocker, adjusting screw and valve tip, points below the push tube to a worn follower roller, roller pin or cam lobe. Resetting the clearance alone only hides the wear.

When a valve is scrapped

Refacing removes metal from the face, so a valve with its margin already under the minimum is scrapped, as is one whose stem has necked down below the head. Burning at one spot on the face points to a rotator that stopped turning.

05The other content areas

The T2 test has eight content areas. Each has its own page of free questions:

The ASE T2 Diesel Engines practice test page describes the full question bank. How these questions are written and checked: how our questions are made. Found a mistake? Tell us and we will fix it.

ToolboxPrep is an independent study site, not affiliated with or endorsed by ASE (the National Institute for Automotive Service Excellence). Our questions are original, written from ASE’s published test specifications and task lists and other public sources. They are not actual ASE test questions and not recalled or “brain dump” questions. ASE is a trademark of its owner, and we never use the ASE logo. Standards and service information are cited, not reproduced.