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Wastegate Failure: Symptoms & Causes

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Last Updated on: 27th November 2023, 11:32 pm

The wastegate regulates turbo boost pressure, which can affect the performance and efficiency of the engine.

If a wastegate fails it can cause issues such as the turbo not boosting properly, decreased fuel economy, a problem known as “wastegate rattle”, and the check engine light coming on.

In this article, we’ll discuss the symptoms of wastegate failure, the causes of it, and if you can still drive.

turbo wastegate diagram

Causes of Wastegate Failure

There are various causes, such as the following.

  1. Age and mileage: Wastegates can experience wear and tear as a result of consistent usage and exposure to heat and various environmental factors, potentially leading to issues such as sticking or malfunctioning.
  2. Incorrect installation: Improper installation of the wastegate can result in premature failure or a failure to perform as originally designed.
  3. Poor maintenance: Failing to perform maintenance tasks when needed, such as replacing worn gaskets or seals, can result in wastegate malfunction.
  4. Turbo over-boosting: If the wastegate encounters high boost pressures over what it’s designed for, it can result in failure. This is common on remapped and tuned vehicles.

Symptoms

When a wastegate fails, it can causes various signs and symptoms, including the following.

  1. Reduced engine performance: In cases where the wastegate fails to properly control boost pressure or under-boost, it can result in a decrease in power output and overall performance.
  2. Illuminated check engine indicator: A failing wastegate can trigger the illumination of the check engine light.
  3. Reduced fuel efficiency: In the event of improper wastegate function, inefficient combustion can occur, leading to higher fuel consumption.
  4. Wastegate rattling: When the wastegate malfunctions, you may observe an issue referred to as wastegate rattling. If this happens, you’ll usually hear a clunking or rattling sound on deceleration.
  5. Boost not being produced: If boost pressure is too low, too high, or is inconsistent, it can be a sign of a failing wastegate.

Can You Drive With a Bad Wastegate?

Driving a vehicle with a malfunctioning wastegate is not recommended. Although it might be possible for short distances, prolonged operation can result in significant engine damage.

It’s crucial to repair or replace the wastegate if it’s malfunctioning.

Conclusion

Wastegate failure can result in the inability to regulate turbo boost pressure, resulting in issues such as under-boosting or over-boosting, reduced fuel efficiency and engine performance, etc.

It’s not recommended to drive if it’s faulty and it should be fixed as soon as possible.

References & More Information
  • Andy Lewin

    Andy Lewin is a senior mechanic, ASE qualified master technician, and an experienced automotive engineer. He's passionate about serving the automotive community with the highest-quality and trustworthy information on all things automotive. He loves to write about car repairs, maintenance, car modifications and tuning, faults, and much more.

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