Which statement about detecting induction leaks is commonly recommended?

Which statement about detecting induction leaks is commonly recommended?

• A. Smoke test with a strong vacuum to reveal leaks
• B. Measure oil viscosity
• C. Check exhaust backpressure
• D. Inspect spark plug wires

Answer: (A)

When checking for induction leaks, you want a method that makes air leaks clearly visible in the intake path. A smoke test uses a smoke machine to introduce visible smoke into the intake while vacuum is applied, so any leak lets smoke escape at the leak site. This direct visualization makes even tiny leaks easy to locate, and using a strong vacuum pulls the smoke through all corners and small passages, increasing reliability of detection. It’s quick, non-destructive, and widely recommended for pinpointing leaks that might not be obvious by eye or by listening. Other options don’t target the problem: oil viscosity relates to lubrication, not air leaks; exhaust backpressure pertains to the exhaust system; inspecting spark plug wires concerns ignition, not leaks in the induction path.

When checking for induction leaks, you want a method that makes air leaks clearly visible in the intake path. A smoke test uses a smoke machine to introduce visible smoke into the intake while vacuum is applied, so any leak lets smoke escape at the leak site. This direct visualization makes even tiny leaks easy to locate, and using a strong vacuum pulls the smoke through all corners and small passages, increasing reliability of detection. It’s quick, non-destructive, and widely recommended for pinpointing leaks that might not be obvious by eye or by listening.

Other options don’t target the problem: oil viscosity relates to lubrication, not air leaks; exhaust backpressure pertains to the exhaust system; inspecting spark plug wires concerns ignition, not leaks in the induction path.