ASE A1 Engine Repair practice test: free drill and what to know

The ASE A1 Engine Repair test is 55 questions (45 scored) in 75 minutes on engine diagnosis, cylinder heads and valve trains, engine blocks, and lubrication and cooling. The free drill below is 12 original A1-style questions at the real pace, with every answer explained, followed by the tests, measurements and traps the A1 keeps coming back to.

55
questions, 45 scored: 75 min
on the real test: 4
content areas: 12
free drill questions

Last checked 22 October 2026 · Test length from ASE's Automobile study guide (2026); rules from standard service practice

Free drill: 12 original ASE-style A1 questions at the real test's pace, then every answer explained. No sign-up.

12
questions
16:22
time limit
Free
every answer explained

By the LifeScore Editorial Team · Updated 22 October 2026 · How we check facts · How this is scored

What is on the ASE A1 Engine Repair test?

General engine diagnosis; cylinder head and valve train; engine block; lubrication and cooling systems; fuel, electrical, ignition and exhaust checks an engine repair needs. The real test is 55 questions (45 scored) in 75 minutes.

The A1 content areas and what the questions ask
Area	What the questions ask
General engine diagnosis	Noises, smoke color, oil and coolant consumption, compression, cylinder leakage, vacuum and oil pressure tests, and what each result points to
Cylinder head and valve train	Head warpage, valve guides and seals, valve and seat service, springs, camshafts, lifters, timing belts and chains, and head bolts
Engine block	Bore taper and out-of-round, deck warpage, crankshaft and bearing measurements, pistons, rings and connecting rods
Lubrication and cooling	Oil pumps and pressure, thermostats, water pumps, radiators and caps, coolant types, cooling fans and leak tests

ASE's task list for A1 also includes the fuel, electrical, ignition and exhaust checks a technician makes before or after an engine repair, such as confirming a misfire is mechanical before pulling a head. Our questions cover those where they decide an engine diagnosis.

The test is about diagnosis and measurement more than assembly. A question rarely asks how to do a job; it asks which test proves the fault, which reading is out of limit, or which cause fits every symptom.

Which A1 tests and measurements do I need to know cold?

The tests that separate one engine fault from another, and the measurements that decide whether a part is reused. Most A1 points come from knowing what a good and a bad reading look like.

Compression test: a cylinder that rises with a little oil added has ring wear; one that stays low points to valves or the head gasket; two low cylinders side by side point to a gasket between them.
Cylinder leakage test: air at the tailpipe is an exhaust valve, at the intake an intake valve, at the oil filler the rings, bubbles in the radiator a head gasket or crack.
Vacuum gauge at idle: steady 17 to 21 inches of mercury is normal at sea level; a steady low reading suggests late timing or a leak; a regular drop of the needle suggests a valve that is not sealing.
Smoke: blue is oil, white and sweet-smelling is coolant, black is a rich mixture.
Measurements: taper (top minus bottom), out-of-round (largest minus smallest at one height), oil clearance (bearing inside diameter minus journal, or Plastigage), head and deck warpage with a straightedge and feeler gauge.

Learn each one as a pair: the test and what each result means. The wrong options on A1 are usually a real fault that the reading in the question rules out.

The formulas our A1 questions use
Rule	How it works
Displacement	0.7854 × bore² × stroke × number of cylinders (cubic inches); × 16.387 for cc
Compression ratio	(swept volume + clearance volume) ÷ clearance volume
Cylinder taper	Diameter at the top of ring travel − diameter at the bottom
Oil clearance	Bearing inside diameter − journal diameter (or read with Plastigage)

What do ASE A1 questions look like?

Short shop situations with four options: a reading, a measurement against a limit or a symptom to match to its cause. Try it before you open the working below.

ASE-style question 1 · Engine measurement
A cylinder measures 3.6248 in at the top of ring travel and 3.6221 in at the bottom. The maximum allowed taper is 0.0020 in. What is the taper, and what does it mean?
1. A0.0027 in; over the limit, so the cylinder needs machining or the block replacing
2. B0.0027 in; within the limit
3. C0.0014 in; within the limit
4. D3.6248 in; over the limit
Worked answer
A: 0.0027 in; over the limit, so the cylinder needs machining or the block replacing. Taper is the top-of-travel diameter minus the bottom: 3.6248 − 3.6221 = 0.0027 in. That is more than the 0.0020 in limit, so the bore must be machined oversize (or sleeved) before new rings will seal.
1. Taper = top diameter − bottom diameter.
2. 3.6248 − 3.6221 = 0.0027 in.
3. 0.0027 in is over the 0.0020 in limit.
The trap: Halving the difference (0.0014 in). Halving is for out-of-round on some charts, never for taper.

These were written for this page and are not in any mock or drill. More are on ASE practice questions.

More A1 practice

Four A1 drills of 12 and A1 in each of eight full mocks, every answer explained like the ones on this page.

The ASE Pass Pack gives you 8 full mocks on the real clock, 20 drills of 12 questions for the sections that cost you points, and a predictor that turns your mocks into the odds of reaching your target. One payment, no subscription, and your free score stays free.

Prep courses for these tests usually cost $19 to $129. The ASE Pass Pack is US$39 (£29), once.

See the ASE Pass Pack How our questions are built and checked

8
timed mocks: 20
topic drills: 1
score predictor

How do I answer "Technician A says, Technician B says" questions on the ASE A1 test?

Judge each technician's statement on its own, as true or false, before you look at the four options. Then the answer is mechanical: only A true, only B, both or neither.

Read the situation once and note the symptom or the reading.
Cover B. Is A's statement true for this situation? Write T or F.
Cover A. Is B's statement true? Write T or F.
Pick the option that matches: T and F is "A only", F and T is "B only", T and T is "Both", F and F is "Neither".

The trap is letting one statement colour the other. Two technicians can both be right about different causes, and a statement can be true in general but wrong for the situation in the question. Words like "always", "only" and "proves" usually make a statement false, because diagnosis rarely works that way.

"Neither" is a real answer, not a trick. On our tests the four keys come up about equally often, so do not avoid one because you picked it last time.

ASE-style question 1 · Diagnosis
An engine has a steady miss. A cylinder leakage test on the dead cylinder shows 45% leakage, and air can be heard at the throttle body. Technician A says the intake valve is not sealing. Technician B says the piston rings are the cause. Who is right?
1. AA only
2. BB only
3. CBoth A and B
4. DNeither A nor B
Worked answer
A: A only. Where the air comes out tells you where it leaks. Air at the throttle body or intake means an intake valve; at the tailpipe, an exhaust valve; at the oil filler or PCV, the rings; bubbles in the coolant, a head gasket or crack.
1. Air is heard at the throttle body.
2. That path runs past an intake valve.
3. Rings would vent into the crankcase, so B is wrong.
The trap: Treating a high percentage as proof of ring wear. The percentage says how bad; the sound says where.

Where do people lose points on the ASE A1 test?

On rules they half-remember and on statements that are true in general but wrong for the situation. These are the ones our explanations correct most often.

Halving the bore difference for taper. Taper is the full difference between the top and bottom of ring travel.
Replacing a part on a single reading. A low compression cylinder needs a wet test or a leakage test before you decide rings or valves.
Forgetting torque-to-yield bolts. They are tightened in sequence and stages, often with a final angle, and usually replaced, not reused.
Mixing up coolant faults. A stuck-open thermostat makes the engine run cold; a stuck-closed one makes it overheat.
Reading a vacuum gauge without the engine warm and at idle. The normal ranges assume both.

How long is the ASE A1 test, and how is it scored?

The ASE A1 test is 55 multiple-choice questions in 75 minutes, 45 of them scored and 10 unscored research questions. ASE publishes no fixed passing percentage; you get pass or fail, with a breakdown by content area.

The real A-series tests, with where each fact comes from
Who gives it	The National Institute for Automotive Service Excellence (ASE), by appointment at Prometric test centersPublished by the ownerASE, "Testing": registration and Prometric test centers
How it is split	One test per system (A1 Engine Repair to A9 Light Vehicle Diesel). Each test is booked, timed and scored on its ownPublished by the ownerASE, "Automobile & Light Truck Certification Tests, A Series: A1-A9"
Questions	40 to 50 scored multiple-choice questions per test, plus 10 unscored research questions you cannot tell apartPublished by the ownerASE, "The Official ASE Study Guide: ASE Automobile Tests" (2026)
Time	60 to 90 minutes per test, depending on the testPublished by the ownerASE, "The Official ASE Study Guide: ASE Automobile Tests" (2026)
Passing score	Not published as a percentage. A panel sets the standard for each test, and you get pass or fail with a breakdown by content areaPublished by the ownerASE, "The Official ASE Study Guide: ASE Automobile Tests" (2026)
Cost	A $34 registration fee plus a fee for each test; 2026 guides quote about $62 per standard test. Check ase.com before you bookSourcedTorquePrep, "ASE Certification Cost 2026: Test Fees & Renewals"
Certification	A pass plus 2 years of hands-on work experience (a two-year automotive degree can count for one). Certifications last 5 yearsSourcedUniversal Technical Institute, "ASE Certification: How To Become ASE Certified"

Our free A1 drill is 12 questions at the real test's pace, and each full mock has 20 A1 questions on the same pace. Because ASE does not publish a percentage, we use 70% as a practice target with a margin, and say so on every result. More on that is in ASE passing score.

Which ASE test should I take after A1?

The one closest to the work you do. Most technicians pair tests by system, and each one below has its own free drill.

ASE A4 Suspension and Steering
Steering systems (columns, gears, power steering, linkage, electric steering); suspension systems; wheel alignment diagnosis and adjustment; wheels and tires
ASE A5 Brakes
Hydraulic system; drum brakes; disc brakes; power assist; parking brakes, wheel bearings and electrical; ABS and electronic brake control
ASE A6 Electrical/Electronic Systems
General electrical diagnosis; battery; starting and charging systems; lighting; gauges and driver information; horn, wiper and accessories; body electronics and networks
ASE A8 Engine Performance
General engine diagnosis; ignition system; fuel, air induction and exhaust; emission control; computerized engine controls and OBD II

Or take the free ASE practice test, which scores all five tests in one sitting, and see the whole path in the ASE certification test guide.

Frequently asked questions

Is A1 the hardest ASE test?

Not usually, but it is broad. Many technicians find A6 and A8 harder, because they lean on electrical diagnosis.

How many questions are on the ASE A1 test?

55: 45 scored and 10 unscored research questions, in 75 minutes.

What score do I need to pass A1?

ASE does not publish a percentage; a panel sets the standard. We use 70% as a practice target.

Is this drill the real ASE test?

No. It is ASE-style practice with original questions. LifeScore is not affiliated with ASE.

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