ASE Prep Lab

ASE A1 Engine Repair — Free Course & Practice Test

The complete ASE A1 course, free on YouTube: 41 video lessons built from ASE's published A1 task list, with a printable workbook for every module. The ASE A1 exam itself is 55 questions (45 scored + 10 unscored) in 75 minutes.

Engine diagnosis, cylinder head and valve train, block, lubrication and cooling — the complete A1.

Course modules — watch free on YouTube

Printable workbooks (Etsy)

Prefer to study on paper? Each module has a printable follow-along workbook with worksheets and practice questions drawn from the same 300-question bank as the video course.

ASE A1 practice test — sample questions

Seven questions from the ASE A1 question bank, spread across the modules. Pick your answer, then open the reveal to check it and read the explanation.

Sample question 1 (QA-31, Module 1)

An engine leaks oil from the valve cover one week after the valve cover gasket was replaced. The most likely cause is:

  1. Excessive crankcase pressure
  2. A defective new gasket in every case
  3. Worn piston rings
  4. Installation error — a pinched or displaced gasket, uneven torque, or an uncleaned sealing surface during the recent repair
Show answer

Answer: D. A leak that begins immediately after a repair points first at the repair itself: gasket seating, torque sequence, and surface preparation. Distractors: A and C are engine-condition causes that would have leaked before the gasket job too. B blames the part without inspecting the installation. Source: Task A4.

Sample question 2 (QA-91, Module 1)

A cylinder shows normal cranking compression but low running compression, and its running reading responds weakly to a snap of the throttle. This combination most likely indicates:

  1. A valve train fault — such as a worn camshaft lobe or collapsed lifter — that limits valve lift at running speed while static sealing remains good
  2. Worn piston rings
  3. A head gasket leak
  4. Low fuel pressure
Show answer

Answer: A. Running compression measures breathing, not just sealing: a valve that seals at cranking but barely opens at speed starves the cylinder dynamically. Worn lobes are the classic find. Distractors: B would lower the cranking reading too. C would show in cranking and leak-down results. D is not visible in a compression gauge at all. Source: Task A9.

Sample question 3 (QB-10, Module 2)

Valve spring installed height is measured:

  1. With the spring removed, at free length
  2. By counting the spring's coils
  3. From the spring seat on the head to the underside of the retainer, with the valve and retainer installed; shims under the spring correct height (and therefore seat pressure) to the manufacturer's specification
  4. From the valve tip to the rocker arm
Show answer

Answer: C. Installed height is a dimension of the assembled valve train, and it sets closed-spring pressure: too tall is weak, too short over-stresses. Shims restore it after seat and valve machining sink the valve. Distractors: A measures free length, a different check. B counts a design feature. D measures a lash-related gap, not spring height. Source: Task B4.

Sample question 4 (QB-30, Module 2)

After an overhead cam head is resurfaced, the camshaft binds when its caps are torqued, though the journals measure in specification. The likely cause is:

  1. Incorrect valve lash
  2. Camshaft bore (caps and pedestal) misalignment — the overheated head warped along the cam tunnel, so straight journals sit in a bent bore
  3. Weak valve springs
  4. Excessive end play
Show answer

Answer: B. A bent cam tunnel binds a straight cam; the free-rotation check with caps torqued — and bore alignment measurement — is the inspection that catches it, and line boring or head replacement is the correction. Distractors: A, C, and D are valve-train dimensions that cannot bind a cam in its bores. Source: Task B13.

Sample question 5 (QC-14, Module 3)

A main bearing insert shows heavy wear at both edges of its face with a polished center band (an hourglass pattern). This wear pattern most likely indicates:

  1. Normal long service
  2. A journal or bore geometry problem — such as a tapered journal or misaligned main bore — concentrating load at the insert's edges
  3. Dirty oil
  4. Excessive oil pressure
Show answer

Answer: B. Bearings are witnesses: where the insert wears is where the load was. Edge loading points at geometry — journal taper or bore misalignment — and correcting only the insert leaves the cause in the block. Distractors: A — normal wear is even and gradual. C embeds in the center of the bearing face, a different pattern. D does not selectively load edges. Source: Task C9.

Sample question 6 (QD-27, Module 4)

A radiator pressure cap that cannot hold its rated pressure causes:

  1. A lowered system boiling point — coolant boils and is expelled at temperatures the engine should tolerate, producing overheating and coolant loss with no component leak
  2. Higher coolant pressure
  3. Improved cooling
  4. A stuck thermostat
Show answer

Answer: A. Pressure is half the cooling system's antifreeze: each pound of cap pressure raises the boiling point, so a weak cap converts normal operating temperature into boil-over. Caps are tested on a cap tester against their rating, not judged by appearance. Distractors: B and C reverse the failure. D names an unrelated component. Source: Task D7.

Sample question 7 (QE-31, Module 5)

An engine will not run, fuel and spark are both absent, and the PCM's 5-volt reference measures 0 volts with a shorted sensor connected. The correct diagnosis direction is:

  1. Replace the PCM immediately
  2. Replace the fuel pump
  3. Replace the coils
  4. Isolate the shorted sensor or harness branch by disconnecting sensors on the reference circuit one at a time — a single shorted component can pull the shared reference down and disable the whole engine management system
Show answer

Answer: D. Shared-reference circuits fail together and recover together: the reference returns when the short leaves the circuit, naming the culprit without a single module being replaced. Distractors: A condemns the victim of the short. B and C are downstream devices of a dead reference. Source: Task E5.

All 300 questions for ASE A1 — with full answer keys — are in the printable workbooks above, and every one is worked through in the free video lessons.