ASE A8 · Engine Performance
General Diagnosis
Broad engine performance diagnosis: base engine mechanical tests, vacuum, compression and leak-down, cam timing, cooling, oil-related issues, and battery, starting and charging effects.
- Questions on the A8 test
- 12
- Share of the test
- 24%
- GearheadPass questions
- 20
- With exhibits
- 5
What this area covers
ASE's task list for General Diagnosis on the A8 Engine Performance test groups into these tasks. Expect diagnosis-first questions: what's the most likely cause, what should be checked next, and which technician is right.
- Concern verification and research
- Base engine and mechanical testing
- Compression, leak-down and power balance
- Valve adjustment and cam timing
- Cooling system and fan checks
- Battery, starting and charging effects
How to study it
- This area carries 12 of the A8 test's questions (24%). Give it study time in proportion.
- Work the free questions first, then read every explanation, including the ones you got right; the reasoning is what transfers to new questions.
- 2 of the 5 free questions here are Technician A/B items. Judge each statement on its own before you pick A only, B only, Both or Neither.
- 2 free questions use an exhibit. Read the exhibit's numbers before the answer options.
- Always confirm specifications in the vehicle manufacturer's service information. Test questions assume you would.
Free practice quiz
5 General Diagnosis questions with explanations
All 20 General Diagnosis questions are in the app
Plus a full-length A8 mock, flash cards, and English or Spanish on every question.
More A8 content areas
A8 · 8 questions on the test
Ignition
Diagnosing ignition-related no-start, misfire, knock, power loss and emissions problems, including primary and secondary circuits, coils, sensors, and ignition and engine control modules.
A8 · 9 questions on the test
Fuel, Air Induction & Exhaust
Diagnosing fuel delivery, air induction and exhaust problems on port and direct injection engines: fuel trim, pumps and pressure, injectors, throttle bodies, vacuum leaks and turbochargers.
A8 · 8 questions on the test
Emissions Control
Diagnosing emission control systems: PCV, EGR, secondary air injection and catalytic converters, and evaporative (EVAP) controls, using scan data and DTCs.
A8 · 13 questions on the test
Computerized Engine Controls
Diagnosing engine computer systems: DTCs, freeze frame and OBD II monitors, faults with or without codes, sensors and actuators, power and ground circuits, PCM programming and networks.