ASE A1 Engine RepairEngine Block AssemblyEasy
A technician is performing a cylinder leakage test. With the piston at Top Dead Center (TDC) on the compression stroke, air is supplied to the cylinder, and a significant amount of air is heard escaping from the exhaust system. This indicates a problem with which of the following components?
- AHead gasket
- BPiston rings
- CExhaust valve
- DIntake valve
Show answer & explanationAnswer & explanation
Correct answer: C. Exhaust valve
Air escaping from the exhaust system during a cylinder leakage test indicates that the exhaust valve is not seating properly, allowing air to pass through.
Why the other options are wrong
- A. Air escaping into an adjacent cylinder or the cooling system would indicate a head gasket issue.
- B. Air escaping from the oil filler cap or dipstick tube would indicate an issue with the piston rings.
- D. Air escaping from the intake manifold would indicate an issue with the intake valve.
Cylinder Leakage Test - Exhaust Valve Leak
A cylinder leakage test identifies the source of compression loss. Air escaping from the exhaust indicates a faulty exhaust valve.
- Performed with piston at TDC on compression stroke.
- Compressed air introduced into cylinder.
- Listen for air escaping from various engine areas.
Memory trick: Leakage Check: Where the Air Goes, There the Problem Grows.