Engine Repair & Rebuild
From leaks and misfires to full rebuilds.
The Engine Repair & Rebuild certification proves you can diagnose, repair, and rebuild internal combustion engines across 4-cylinder to V-8 platforms, timing systems, valvetrain, bottom end, oiling, and cooling. Everything below is free, no login, no paywall. Work through the skill areas, drill them in Study Mode, and when you're ready, prove it with the certification exam.
Your readiness to certify
Drill all 60 concepts in Study Mode. Mark each one "Got it" once you know it cold. When every concept is cleared, you're ready for the ENG exam.
What you'll be able to do
- Compression, leak-down, and cylinder health diagnostics
- Timing belt and timing chain service across major platforms
- Head gasket diagnosis and replacement
- Valvetrain: rocker arms, lifters, camshaft service, lash adjustment
- Bottom end: piston rings, rod bearings, main bearings
- Oil pump replacement, oil leak diagnosis
- Cooling system integration with engine internals
Skill areas
7 lessons, each one short enough to finish in a break. Every lesson teaches the system from the ground up, ends with a call to work, and tracks which concepts you have cleared.
Compression
Compression testing is the single most valuable mechanical health check you can run on an engine without pulling it apart.
Timing
Valve timing is the choreography that keeps pistons and valves sharing the same space without ever touching.
Head Gasket
The head gasket seals three systems against each other.
Valvetrain
The valvetrain converts cam lobe profiles into precisely timed valve events thousands of times per minute.
Bottom End
The bottom end, crankshaft, rods, pistons, bearings, and the cylinder bores they live in.
Oil Systems
Oil pressure is the heartbeat of the engine: every bearing, lifter, and cam lobe survives on a pressurized film of oil a few ten-thousandths thick.
Cooling
The cooling system carries away roughly a third of the engine's combustion heat, and it only takes one weak link, a lazy fan, a stuck thermostat.
Studied the material? Get ENG certified.
The Engine Repair & Rebuild exam turns what you just learned into a verifiable credential drivers and shops can look up. 60 questions · 90 minutes · 75% to pass · Free.
Studying on MechanicRank is free forever. There's no obligation to take the exam.
The work these lessons teach.
Real jobs from Supercanic trucks — the systems above, out in the field.
Real-world cost guides for this system.
See what customers pay for the jobs this track teaches, parts, labor hours, and state-by-state ranges from our repair cost estimator.
Standards and further reading
Primary sources behind this page. Federal safety, emissions and consumer-protection references, worth reading before you authorize any repair.
- ASE certification The national standard for automotive technician testing and certification.
- EPA vehicle & engine certification Emissions standards that govern what may be replaced or modified.
- SAE International The engineering body behind fluid, fastener and diagnostic standards.
- California Bureau of Automotive Repair Licensing, consumer complaints and shop regulation in California.