Specialist built smoke machines can be used to trace leaks in almost any automotive system. This is possible because an engine is like a big lung that mixes the fuel vapor and air to create a highly flammable and explosive mixture.
The exact mix of oxygen and fuel vapor is highly controlled to make sure that all the fuel is burnt and not let into the atmosphere. Any excess fuel that does leave the engine system causes pollution. These are the two main reasons why leak testing is important, to check that there are no holes in the system and that the engine is being served the correct mixture.
Evaporative Emission Control System
The Evaporative Emission Control System (EVAP) is used to help reduce emissions from reaching the atmosphere. It is common for this to have a fault or show an engine light on the dashboard. It helps to keep pollution levels down and stop fuel vapor entering your car interior, this can smell especially bad.
For more information on using nitrogen read the SAE International Technical Papers on leak-testing hazards. These are about using air instead of an inert gas to test a vehicle’s fuel vapor system for Gasoline vehicles.
How to use a smoke leak detector
We have already spoken about the importance of leak testing for an engine, here is a quick guide to testing anywhere on your car or truck engine.
- First, find the correct adapter and connect your smoke detector to the system you are trying to test. A rudimentary adapter can easily be made from a bottle and tape if needed to fit a certain hole, just make sure smoke doesn’t escape from the edges.
- Plug your smoke detector into the relevant power source, some are able to be run off a 12-volt system while others will need to be connected up to a mains source.
- Top up your smoke detector with the correct oil fluids as many machines use oil with UV particles included.
- Turn on your smoke machine and leave it for a few minutes to fill the entire system. Once you can see smoke coming from the other end of the system you are ready to check for leaks.
- Now check over the whole system for any signs of smoke escaping where it shouldn’t. A UV light can be used to help see the leaks, this will make it very obvious. A bright torch can also help.
For more information about EVAP testing please see these articles from MOTOR Magazine.
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