Can a Bad Wastegate Cause Misfire? (Explained)
Updated: Feb 1
✔ This article has been fact checked.
A misfire is a common issue that can occur in a vehicle's engine. It refers to a situation where one or more of the cylinders in the engine fails to fire properly, resulting in a loss of power and potentially damaging the engine.
Yes, a bad wastegate can cause a misfire due to an improper regulation of turbo boost pressure, causing the engine to run too rich or lean.
In this article, we will explore whether a bad wastegate can cause a misfire and what the symptoms of a faulty wastegate might be.
Table of Contents:
What Is a Wastegate?
A wastegate is a valve that is used to control the amount of exhaust gases that flow through a turbocharger. It is typically found in vehicles with turbocharged engines and is used to regulate the amount of boost pressure that is produced by the turbocharger.
The wastegate is connected to the exhaust manifold and is controlled by a actuator, which is typically a small valve or rod that is activated by a solenoid or other control device.
When the wastegate is open, it allows some of the exhaust gases to bypass the turbocharger, reducing the amount of boost that is produced.
When the wastegate is closed, it directs all of the exhaust gases through the turbocharger, increasing the amount of boost that is produced.

How a Bad Wastegate Causes Misfire
A bad wastegate can cause a misfire in a vehicle's engine. This is because the wastegate is responsible for regulating the amount of boost that is produced by the turbocharger, and if it is not functioning properly, it can result in an excess or deficiency of boost.
If there is too much boost, it can cause the engine to run lean, meaning there is not enough fuel being injected into the cylinders to support the amount of oxygen that is present. This can result in a misfire, as the cylinder will not have enough fuel to ignite and will not fire properly.
On the other hand, if there is not enough boost, it can cause the engine to run rich, meaning there is too much fuel being injected into the cylinders relative to the amount of oxygen present.
This can also result in a misfire, as the excess fuel can interfere with the ignition process and prevent the cylinder from firing properly.
Yes, a bad wastegate can cause a misfire by disrupting the balance of fuel and air in the engines cylinders, which is necessary for the engine to run smoothly.
The video below shows what a misfire sounds like.
Symptoms of a Bad Wastegate
There are several symptoms that may indicate a problem with the wastegate in a vehicle.
1. Loss of power
The wastegate plays a crucial role in regulating the amount of boost pressure produced by the turbocharger. This boost pressure is necessary for the engine to perform at its best.
If the wastegate is not functioning properly, it may not be able to regulate the boost pressure effectively, leading to a lack of power in the engine. The engine may struggle to produce the necessary amount of power under load, causing a decrease in performance and acceleration.
2. Overboost
In some cases, a malfunctioning wastegate may cause an overboost, meaning that too much turbo boost pressure is produced. This can result in too much power being produced by the engine, potentially causing damage to the engine and other components.
An overboost can also lead to a loss of control over the vehicle, making it difficult to drive safely.
3. Check engine light
If the wastegate is not working correctly, it can affect the engine's performance, causing it to run poorly. This can trigger the check engine light to come on, alerting the driver of a potential problem.
The check engine light should not be ignored, as it may indicate a serious issue that needs to be addressed.

4. Decreased fuel efficiency
The wastegate regulates the amount of boost pressure, which directly affects the engine's fuel efficiency. An incorrect regulation of boost pressure by the wastegate can lead to an excess or deficiency of boost, which can negatively impact the fuel efficiency of the vehicle.
This can result in higher fuel consumption, which can be costly in the long run.
5. Excessive exhaust smoke
If the wastegate is allowing too much exhaust gas to bypass the turbocharger, it can result in an excessive amount of smoke being emitted from the exhaust. This smoke can be a visual indicator of a problem with the wastegate and can also contribute to air pollution.

6. Strange noises
A faulty wastegate may cause unusual sounds such as whistling or hissing noises as the exhaust gases pass through it. These sounds can be a clear indication of a problem with the wastegate and should not be ignored.
In some cases, the wastegate may also produce a rattling or clanging sound if it becomes damaged or is failing. These noises can indicate that the wastegate needs to be replaced as soon as possible to prevent further damage to the engine and other components.
Can You Drive With a Bad Wastegate?
It is not recommended to drive a vehicle with a bad wastegate, as it can lead to a misfire and potentially cause damage to the engine.
If you suspect that there may be a problem with the wastegate in your vehicle, it is important to have it checked and repaired as soon as possible. Driving with a bad wastegate can lead to a loss of power and fuel efficiency, and in severe cases, it can cause serious damage to the engine.
In some cases, it may be possible to drive a short distance with a bad wastegate, but it is important to be aware of the potential risks and to take the necessary precautions.
If you do need to drive with a bad wastegate, it is important to avoid heavy acceleration and to keep an eye on the temperature and performance of the engine.
If you notice any unusual symptoms or if the engine begins to misfire, it is important to stop driving and have the vehicle repaired as soon as possible.
Conclusion
A bad wastegate can potentially cause a misfire in a vehicle's engine by disrupting the balance of fuel and oxygen in the cylinders.
Some of the symptoms of a bad wastegate include a lack of power, a check engine light, decreased fuel efficiency, excessive exhaust smoke, and strange noises.
It is not recommended to drive a vehicle with a bad wastegate, as it can lead to a misfire and potentially cause damage to the engine. If you suspect that there may be a problem with the wastegate in your vehicle, it is important to have it checked and repaired as soon as possible.
Sources
Rick Popely. (Jun 27, 2021) https://www.cars.com/articles/what-is-a-misfire-and-what-causes-it-437350/
(Oct 12, 2020) https://turboturbos.com/blogs/news/symptoms-of-a-failing-wastegate
Wikipedia. "Wastegate" https://en.wikipedia.org/wiki/Wastegate