What can be used to detect a vacuum leak at an intake manifold gasket?
A) Coolant
B) Dye
C) Propane
D) Spray water

Question

Quizplus · Accepted Answer

Propane can be used to detect vacuum leaks at an intake manifold gasket because it is a flammable gas that will cause the engine RPM to increase when it is sprayed near the intake manifold gasket. This is due to the propane being sucked into the engine through the vacuum leak, causing a richer fuel mixture and an increase in RPM. This method is commonly referred to as the "propane test."

What Can Be Used to Detect a Vacuum Leak at an Intake