Tech A says that a bad cam lobe or broken valve spring will show up during a running compression test. Tech B says that when performing a cylinder leakage test, the engine must be running during the test. Who is correct?

Tech A is correct

Explanation:

A running compression test is performed to check whether the engine is able to move air inside and outside of the cylinder or not. During performing a running compression test, the engine is running. it shows how the cylinder is able to take in and take out the air.

If a vehicle's cam lobe is bad or have a broken valve spring, it will show up in the running compression test as less air will enter the cylinder and leaves the cylinder. Thus performing this test will show a bad cam lobe or broken valve spring.

Hence the answer is Techician A is correct.