Noises
Turbo whistle when accelerating: when it is normal and when not
A soft whistle when you accelerate is the normal sound of a turbo. If it turns loud, high-pitched like a siren or like a vacuum cleaner, and the car loses power or smokes, there is usually a leak in the boost hoses or wear in the turbo itself.
See a garage soonNoises
Reviewed by Daniel Morales, founder of Reprorace SL, on
Is it serious? Can I keep driving?
Carefully, and only as far as the garage. If it is just louder but the car pulls fine, see a shop soon. If it also blows blue or black smoke, goes into limp mode or you hear metallic scraping, drive as little as possible: a failing turbo can push oil or debris into the engine.
A careful, general answer: only someone who inspects the car can say whether it is safe to drive. When in doubt, stop somewhere safe and call for assistance.
Most likely causes
- Leaking hose or intercooler: sounds like a puff when accelerating and the boost pressure drops.
- Loose clamp: the hose pops off under pressure.
- Turbo wear: play in the shaft: a high-pitched whistle, sometimes with blue smoke.
- Exhaust leak ahead of the turbo: the turbo spins less and you hear a puffing sound.
Listed from more to less common in general; on your car they may be different. A fault-code reading and a check at the garage confirm which one it is.
To understand it better: How does a turbocharger work and what does P0299 mean? What is a mass airflow sensor and what symptoms does it cause when it fails?
Car system: Turbo
What you can check yourself
With the engine cold, check whether a turbo or intercooler hose is loose, split or oily on the outside.
Notice whether the noise comes with a loss of power, smoke or a warning light.
Record the sound while accelerating in a high gear, for the shop.
Safe checks only: with the engine off and cold whenever you look under the hood, without taking anything apart and without touching hot or moving parts.
Related fault codes
- P0299Turbocharger/supercharger A: underboost
- P0234Turbocharger/supercharger A: overboost
- P2263Turbocharger/supercharger A boost system: performance
- P0101Mass or volume air flow sensor A, circuit: range/performance
Generic codes that often come with this symptom. Seeing one does not confirm the cause: it is where the diagnosis starts.
How the ECO-LITE helps diagnose it
Plugged into the OBD socket, the ECO-LITE reads the fault codes of the control units that answer, with the freeze-frame data captured when the fault happened, and shows live data on your phone or computer. With your permission, your garage can see them remotely before you bring the car in.
What to look at here: target and actual boost pressure, airflow and turbo codes such as P0299.
Frequently asked questions
Is it normal for a turbo to whistle?
A soft whistle, yes. It is not normal for it to suddenly get loud or change tone.
What is the whoosh when I lift off?
On some cars, the blow-off valve releases pressure when you lift off the gas. If it did not do it before, check the hoses.
How much does a turbo repair cost?
It depends on the car and on whether it is rebuilt or replaced. Often the fault is a hose, which is far cheaper.
Keep reading
- Turbo: how it works and what fails
- Car loses power: what limp mode is
- Blue smoke from the exhaust: the engine is burning oil
- Black smoke from the exhaust: causes and what to do
- Car symptoms: what they mean and what to do
- Check engine light on: what to do
- How to read and clear your car's fault codes
- OBD fault codes: what each one means