How Much Does Car Smoke Test Costs?

A leak in your vehicle’s emissions system or intake manifold can be difficult to detect, even though it causes performance problems or triggers a diagnostic code.

A smoke test typically costs anywhere from $30 to $150, based on which vehicle systems you’re testing. A smoke test on the intake or PCV system usually costs $60-$100, while testing the EVAP system is usually in the $120-$150 range. The price may also vary based on the shop’s hourly labor rate. 

Cost to Perform a Smoke Test

A smoke test is a diagnostic tool that can be applied to many different vehicle systems.

Depending on where it’s connected and how it’s used, it can be an efficient tool to detect even small leaks in the many different hoses, seals, and system components in your vehicle. 

The cost to have a smoke test performed professionally may be as cheap as $30 at a chain service station like Pep Boys, especially if they’re offering a promotional rate. 

Other garages have quoted prices at $89.99 and $125. In general, you should plan to spend between $60 and $150 for a smoke test on your vehicle. 

Cost for a Smoke Test

The reason for the variations in price is mainly based on what kind of diagnostic test the garage is performing.

A smoke test can be used for many different purposes, depending on where it’s connected and how the smoke is forced throughout the vehicle’s systems and components.

A smoke test is most commonly used for the vehicle’s Evaporative Emission Control (EVAP) system or PCV system. However, there are many other uses for a smoke test.

In states like California where vehicles have to pass a smog check for excessive exhaust, a smoke test can help diagnose any potential problems in the EVAP and exhaust systems so that the vehicle can pass inspection. 

What Can a Smoke Test Diagnose?

In addition to the EVAP system, a smoke test can be used to diagnose problems throughout the vehicle. Anywhere that will hold the smoke is potentially an area that can be checked for leaks using a smoke test.

Let’s take a look at some of the other common uses for this diagnostic tool. 

Smoke Test for Injector Seals ($65 – $95)

If your vehicle has leaking injector seals, you will likely find lean and misfire codes when you run a computer diagnostic.

To find the leaks, there are diagnostic tests that use flammable liquids or gasses while checking for changes in the RPMs.

A simpler way to identify leaks in the injector seals is to connect the smoke machine to a vacuum port on the vehicle and block off the air intake and PCV system.

Any injectors that have leaky seals will start to have visible smoke leaking out around the base. 

Smoke Test for the PCV System ($60 – $100)

With a leak in the PCV system, your vehicle may end up with unmetered air making its way into the intake manifold. This may cause performance issues or you may find a diagnostic error code.

To check for this issue, the smoke machine can be connected at the oil filter neck. If you pressurize the crankcase with smoke, you’ll quickly find any leaks throughout the system, whether they’re from hoses, connections, or even from the valve cover or oil pan gaskets. 

Smoke Test for the Intake Manifold ($65 – $110)

A smoke test is a very efficient way to detect and diagnose a leak in the intake manifold. This is important because even small leaks can cause significant problems for the vehicle.

For this test, the smoke machine should be connected to a vacuum port. As long as the throttle body is blocked off, the smoke will fill the intake manifold and allow the technician to quickly detect and diagnose multiple leaks in a short amount of time. 

Smoke Test for Valves and Pistons ($80 – $115)

A common diagnostic tool for the valves and pistons is a compression tester. However, this test won’t specify whether the problem is with the intake or exhaust valve or the piston.

The only other real alternative to using a smoke test is to disassemble the engine, which is a much more expensive and time-consuming process. 

For this smoke test, the machine can be connected to the spark plug port. If smoke leaks from the oil filter cap, this would indicate that the leak was in the piston or rings.

If the smoke was visible from the intake, it would indicate that the problem was in the intake valve. Smoke coming from the tailpipe would indicate that the issue was the exhaust valve. 

This diagnostic tool allows the technician to check multiple components simultaneously, saving time and money. 

Smoke Test for the Exhaust System ($75 – $105)

Modern vehicles have complex exhaust systems that are typically insulated with heat shields and surrounded by various components that make it difficult to access to check for leaks with traditional methods. 

A smoke test is a simple way to find a leak. As long as the exhaust system is cool, the smoke machine can be connected to the tailpipe using a special adapter.

The smoke will quickly fill the pipe and exhaust system, allowing the technician to see where the smoke leaks from. 

Smoke Test for the Brake Booster ($90 – $120)

If the smoke machine is connected directly to the brake booster, it can be used to check for leaks and failed seals.

If any smoke can be seen coming out of the booster, you’ll know that the seals are bad. Be sure to press and depress the brake pedal several times to move the smoke all through the system. 

Smoke Test for HVAC System ($85 – $115)

Vacuum actuators and switches in the HVAC system can be very difficult to diagnose when there is a problem.

Using a smoke machine, you can push the smoke through the main vacuum supply line for the system and cycle the head unit through the various airflow patterns.

Using the smoke machine’s flow meter gauge, you can determine whether the machine is indicating a leak for a prolonged period. If this is the case, it could mean a problem with the actuator or switch. 

Smoke Test for the Transmission ($100 – $150)

If the transmission or axle is drained of fluid, you can insert the smoke machine nozzle into the dipstick tube or filler hole.

If you find bubbles or drips coming from various areas, it may indicate a leak. Smoke testing is a good way to diagnose transfer case leaks and transmission leaks. 

Smoke Test for Fluid Reservoir Tanks ($35 – $65)

A smoke test can be used to find leaks from various fluid tanks. Any of the plastic reservoirs like those for windshield washer fluid or coolant may become cracked or damaged.

These leaks can be too small to see with your eyes, and the leak may be too slow to immediately locate the source. If you find small amounts of fluid leaking from your vehicle, this can be a quick and easy way to check those areas. 

Cost to Smoke Test Your Evaporative Emission Control System

Running a smoke test on your Evaporative Emission Control system is often slightly more expensive than doing the same test on the vehicle’s intake or CCV system.

Usually, the price is between $60 and $150, with most people paying in the $120-$150 range. 

The Evaporative Emission Control (EVAP) system is where your vehicle collects fuel vapors and eventually recycles them back into the fuel tank.

The EVAP system keeps these harmful vapors from making their way into the environment and your vehicle. In order for the system to operate correctly, it needs to be sealed up tightly without any pressure leaks.

If the EVAP system has a malfunction or leak, it will usually trigger a “check engine” light or other diagnostic code.

A leak in the emissions system can be very difficult to locate, especially since what leaks out are vapors rather than visible liquids or smoke.

Checking your owner’s manual or having a mechanic check the diagnostic code can help narrow down the leak’s location. 

Still, to find the exact location, you’ll need to use some kind of special equipment to find these small, obscure leaks. A smoke test is one of the most common diagnostic tools for leaks within the EVAP system.

If a leak is detected and the EVAP system ends up needing repairs, the costs are usually between $200 and $560, depending on the exact cause of the problem. 

Cost to Smoke Test Your Intake or PCV System

Performing a diagnostic smoke test on your PCV system can check for leaks that are allowing unmetered air to enter into your intake manifold.

It’s usually in the same cost range as doing the smoke test on the intake manifold itself, which is between $60-$100.

Running the smoke test on your PCV system will allow the mechanic to detect leaks in various hoses, gaskets, and connections.

It will also help with identifying leaks in items such as the valve cover and oil pan gaskets, which are sometimes overlooked in other tests. 

For the intake manifold, the smoke machine is connected to a vacuum port (such as the supply line or brake booster), which fills the intake manifold with smoke.

Using this method, the technician can identify and diagnose even the smallest leaks, and they’re able to find multiple leaks in a short amount of time.

This diagnostic tool can end up saving you some money if there are multiple areas of concern. 

How Much is a “Smog” Test?

A “smog” test, or emissions test, costs anywhere from $10 to $75. Where you live, the type of vehicle that you have, and any local regulations may all impact the price.

These tests aren’t required everywhere, so check your state and local regulations to know for sure. 

If you’re running a smoke test on your vehicle because you need to pass a “smog” test, you may be wondering how much these emissions inspections or tests cost.

The price depends on the state because not all states require such inspections. In some states, only certain vehicles are required to be tested. These inspections or tests are sometimes also known as emissions testing. 

Cost for a Smog Test by State

In some states, like Ohio, residents get three free tests each year. However, if they fail those tests, they will have to pay $18 for each additional test. 

The Bottom Line

A smoke test for your vehicle typically costs anywhere from $60 to $150, depending on what kind of test will be performed and where you take it for the work.

If you have diagnostic codes to suggest that you may have a leak in one of your vehicle’s components, a smoke test may be the most cost-efficient diagnostic tool. It can check many areas at one time, and it can detect and diagnose even very small leaks. 

If you live in a state where you need to pass an emissions (“smog”) test or inspection, then a smoke test may be the best and quickest way to find any potential problems so that you can pass inspection and get back on the road.

Not to mention, it’s a good idea to keep your vehicle’s emissions systems in good working order for your own health and safety and for the environment’s sake. 

The best way to help prevent leaks and other problems in your vehicle’s various systems is to keep up with regularly scheduled maintenance.

Routine maintenance and prevention are key to keeping your vehicle running well and up to any state, local, and other environmental standards.