BMW turbo problems: power loss, noise and smoke

Which cars and engines are affected?

Any turbocharged BMW or MINI, petrol or diesel. The checks on this page apply whatever the engine. If you are not sure which engine your car has, put the registration in the enquiry form and we will check.

For other work on these cars, see our BMW and MINI specialist page.

What are the symptoms?

• lack of power
• noisy operation from the turbo
• heavy smoke from the exhaust
• high oil use

When you book, tell us which of these you have noticed, when they started and whether any warning lights are on.

What causes it?

Garrett, a turbocharger maker, says most turbo failures are oil-related: the turbo is starved of oil, or the oil is contaminated. Damage from foreign objects getting into the turbo is the other main cause. Garrett says manufacturing defects are rare.

This matters because a turbo usually fails as a result of something else. If that cause is left in place, the new turbo is exposed to it too.

How do you confirm the fault before fitting parts?

A fault code is not a repair, and a noisy or smoky turbo is not proof that the turbo is the cause. Before we condemn a turbo, we check:

• the oil feed to the turbo and the oil drain from it
• the condition of the engine oil
• the air filter
• the intake and the exhaust for debris
• the fuel injection

We also read the fault memory with our diagnostic equipment. We then show you what we found and send a written price. No part is fitted until you give your written approval.

What does the repair involve?

• Fix the root cause first, whether that is the oil supply, the oil, the air filter or debris in the intake or exhaust.
• Fit the replacement turbo. Turbo replacement is done in-house.

One UK turbo specialist warns that if the root cause is not fixed, the new unit fails the same way. Once the work is done, we check that the fault has cleared and verify the repair, including a road test where appropriate.

How long does a turbo repair take?

It depends on what the checks find, and on what has to be put right before the new turbo goes on.

Before any work starts, you get a written price and a promised time for your next update. If the car needs to stay with us, ask about a courtesy car when you book.

Is there a recall for the turbo?

Whether a recall applies depends on the individual car, so check your registration on gov.uk. Recall work is done by BMW’s network, not by us.