DIY Smoke Machine for Vacuum or EVAP Leaks: Is It Cheaper and Effective?

If you suspect a vacuum or EVAP leak in your car, you need to have it checked and repaired immediately since it can lead to more pollution in the air, fuel smell reaching inside your car, or a failed emission test. However, EVAP leaks are usually either large or very small like a pinhole and it can be difficult to find. Fortunately, there are ways to find these leaks and one of which is by using a smoke machine. While a smoke machine is one sure way to detect even the small leaks, a professional smoke machine is a bit pricey. It can cost around $130 to $800 to purchase one. Good thing there is a DIY smoke machine for vacuum or EVAP leaks. 

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A do-it-yourself smoke machine can be done at home using materials like a pickle jar, baby oil, cotton t-shirt, BIC pens, ¼-inch ID clear tubing, bicycle pump, soldering iron, and a high-heat plastic or metal safe epoxy. 

DIY Smoke Machine for Vacuum or EVAP Leaks: What is an EVAP Smoke Test?   

The evaporative emission control system or EVAP is an important component of a vehicle since it is the one that keeps gas fumes in the fuel tank from getting in the atmosphere. It is crucial that your EVAP system is always at its best condition. It does not only help the environment by reducing a significant amount of harmful vapors released in the atmosphere, it also keeps these toxic fumes from entering inside your car and keeps the combustion fuel from inflicting a more severe damage to your car’s systems. It basically contains or restricts these fumes from going anywhere and directs them to the engine to be burned. 

However, like many parts of the car, the EVAP system and its components are also subjected to wear and tear. The hoses, rubber tubes, and its other parts can deteriorate over time and it can cause an EVAP leak. You may encounter an EVAP leak code along with an illuminating check engine light which means that there is a problem somewhere in the evaporative emission control system and that a leak has been detected. 

Problems like vacuum and EVAP leaks are quite common. Repairing it can be easy but finding where the leak is can be very difficult. You need to find where it is to repair and because leaks can affect the overall efficiency of your car. To find a leak, you may have to use some special equipment like a smoke machine to perform a smoke test. You can purchase a professional smoke machine or choose to use a DIY smoke machine for vacuum or EVAP leaks if you want to save some money.

A smoke test is done so you will know and confirm if there is any vacuum or EVAP leaks in your system. It can also help spot the exact location of the leak. It is done by filling or blowing the EVAP system of your car with smoke from a smoke machine. If you spot any smoke escaping in one of its components, it is an indication that there is indeed a leak. 

A smoke leak test can cost around $80 to $90 and if you want to buy a smoke machine, you can purchase it for $130 to $800, but you can also make a DIY smoke machine for vacuum or EVAP leaks at home. A smoke leak test is capable of finding leaks in the hollow part of the vehicle like the EVAP system, the intake manifold, and the exhaust system. You just have to fill up these systems with smoke and look closely for leaks. You may use a bright flashlight so you can look for the escaping smoke easier. 

It is important that you find the vacuum or EVAP leaks immediately no matter how small it is. Even a small leak with a size of 0.030 inch can affect the engine’s performance and can set off the check engine light. 

DIY Smoke Machine for Vacuum or EVAP Leaks: How Do You Make a Car Smoke Machine?       

Performing a smoke leak test might be one of the most effective methods in determining the exact location of a vacuum or EVAP leaks, but purchasing an expensive smoke machine to perform it might just be too much for many car owners. Why would you spend a lot when you have the internet? You can find videos of tutorials or blogs with simple written instructions on a lot of how-tos and do-it-yourself projects, and making a DIY smoke machine for vacuum or EVAP leaks is one of them  

But how do you make a DIY smoke machine for vacuum or EVAP leaks? Here’s how!

First, you need to prepare a number of materials which you can easily find at home. You will need an empty 24oz pickle jar or clear glass jar with lid, a white sock or t-shirt made of 100 percent cotton, pure baby oil, two BIC pens with caps, about 6 feet of ¼ inch ID clearing tube, christmas tree bit or ¼ inch bit, bicycle pump, high heat plastic or/and metal safe epoxy, soldering iron, and a carb cleaner cap if your soldering iron is made with a metal base. 

To start making your DIY smoke machine for vacuum or EVAP leaks, just follow these simple steps.

• Measure the diameter of the metal shaft of your soldering iron. Make sure that you measure the metal shaft and not its plastic handle portion. 
• After getting the right measurement, take note of it and drill a hole with the exact  size  dead center on the lid of the pickle jar. You need to make sure that you will make a hole big enough to let just the soldering iron’s shaft through and not its handle. The handle of the soldering iron should not get through. 
• If your soldering iron has a metal base or a metal cap around the bottom of its handle where it meets the shaft, you will have to make a shroud for the soldering iron so its metal part will not directly touch the pickle jar’s lid when you insert the soldering iron. You can hollow out the cap from a can of carb cleaner. Then you can slip it around the round base of soldering iron. Doing so makes the cap touch the plastic handle and not the metal cap. Check if the fit is already snug, but make sure that the cap is still slightly loose.   
• Get the lid of the pickle jar and insert the soldering iron and the cap loosely into the hole that you made. Continue and go about half an inch to the side of the cap and make two marks, one on each side of the pickle jar’s lid.
• Get the two BIC pens and take off their caps. Cut the very top of the cap where it is supposed to be closed and create an open hole then cut the extrusion off – the one that holds the pen to your pocket. 
• Make two holes in the pickle jar lid using the ¼ inch bit or the christmas tree bit. Although it is not needed, you can opt to sand the lid’s top to its bare metal. The two holes you made should allow the two pen caps to slide upward from the inside of the lid. With caps being tapered, a tight fit can be made since they will be locked at the top of the hole. 
• Next step is remove the soldering iron and the cap from the lid of the pickle jar and use a plastic/metal safe epoxy to hold the carb cleaner cap to the soldering iron. You can use products like JB Weld since it is able to create about ¼ inch gap between the soldering iron’s metal base plate and the jar’s lid when you insert the iron into the jar. Make sure that the epoxy has set completely before you move the iron. 
• Take the lid of the pickle jar and put JB Weld on the lid’s top and bottom around the two pen caps to make an airtight seal. Be careful when applying it to not get any JB Weld on the rubber seal inside the lid of the pickle jar since it is needed to seal the jar completely. 
• When everything has set, put JB Weld around the carb cleaner cap’s bottom and place it into the center hole which you drilled on the lid of the pickle jar. Applying JB Weld can seal the soldering iron to the lid and with the recently applied JB Weld to hold the cap to the soldering iron, an airtight seal can be created. Wait for 24 hours to dry and completely cure the applied JB Weld.  
• Once everything is set and dried, get the ¼ inch clear tubing and cut it into two parts. One is cut about 4 feet long and the other one about 2 feet long. 
• Put the two clear tubes over the BIC pen caps you placed on the pickle jar lid. 
• Remove the guts out of one BIC pen and cut the sealed end to create a hollow tube. Put the hollow pen on the other side of the two-feet clear tube.
• Get your bicycle pump. Although you can also use a small hand pump such as an air mattress pump, a bicycle pump can do the job better. It is because the small pump tends to move too much air at a faster rate than the bicycle pump, preventing the smoke from staying as concentrated as you want it to be.
• Fit the other side of the BIC pen inside the nozzle of the bike pump and lock it into place. 
• Get the t-shirt or white sock made of 100 percent cotton. Take your time and be patient since you may have to do some trial and error to get the right size.  You can try cutting a small strip of cloth first starting from the bottom of the cotton shirt and start from there. Put the fabric in the pickle jar and test if the tip of the soldering iron can touch it. The idea is to make sure that when you place the lid back on the pickle jar, the tip of the soldering iron will be positioned just enough to touch the cloth and not completely covered or surrounded by the cloth.
• Get the baby oil and completely soak the cotton cloth. Make sure that you use the 100 percent pure one and not the ones with additives. You need to get the cotton cloth dripping wet with oil. When it is already drenched, put in around half an inch of standing oil at the bottom of the jar. The cotton fabric will act as a wick that sucks up the oil when you operate your DIY smoke machine for vacuum or EVAP leaks. That is why you need to put in the extra amount of oil and drench the cloth so it will not burn up. 
• When the cloth and oil has been added in the pickle jar, put the lid  with the iron and the whole assembly back on the jar and plug it in. You may want to use an extension cord to plug the soldering iron in. 
• Wait around five to ten minutes for the soldering iron to heat up and start producing smoke. You can check if your jar or tubes have no leaks by closing both of the tubes. 
• If all is good, hook the two-feet part of the clear tube again to your bicycle pump and the other end, the four-feet one, to the vacuum port. 
• Pump as much smoke as needed to fill the system and look closely for leaks.  

Making a DIY smoke machine for vacuum or EVAP leaks is an inexpensive way to check for leaks and spotting the exact location of the leaks. Most of the materials can be found in your home. Just make sure that you follow the instructions carefully to make sure that you get the desired results.