What can I find with a smoke machine besides EVAP leaks?
Short answer: A smoke machine finds intake vacuum leaks, boost leaks, exhaust leaks, wind and water leaks, and some oil and coolant leak paths, often in minutes.
EVAP testing is what most people buy a smoke machine for, but it earns its keep on many other jobs. Fill the intake through a vacuum line or a sealed intake adapter, and smoke pours out of cracked hoses, leaking gaskets, PCV problems and loose couplers. That turns a lean code diagnosis from guesswork into a visible answer.
On turbo engines, smoke the charge-air system to find boost leaks at intercooler hoses and clamps. Smoke introduced into the exhaust finds leaks ahead of oxygen sensors that can skew readings and set catalyst codes. Body shops and detail shops also use it to trace wind noise and water leaks around doors and windshields.
Use the machine at the low pressure it was designed for, especially on EVAP systems, and follow the maker's instructions for the fluid used to make smoke. Never introduce smoke into a running engine, and keep ignition sources away from fuel systems.
Tools used for this job
General guidance only. Follow the vehicle and tool manufacturer's procedures, and confirm vehicle coverage on the tool maker's list before buying.