Excessive boost in a turbocharged engine should be checked by inspecting the wastegate.

• A. True
• B. False
• C. Not sure
• D. N/A

Answer: (A)

The main idea is that boost pressure in a turbocharged engine is controlled by the wastegate. The wastegate opens to bypass exhaust away from the turbine when the target boost is reached, keeping boost from climbing higher. If you’re seeing excessive boost, it points to a potential wastegate issue—such as the actuator not moving, a weak or broken spring, a sticking diaphragm, a leaky or kinked vacuum/pressure line, or a misadjusted linkage—so inspecting the wastegate is the logical first diagnostic step. If the wastegate and its actuation are functioning properly, you’d then investigate the boost controller, hoses, and other parts of the boost system. So, excessive boost should be checked by inspecting the wastegate.