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Turbocharged engines produce a satisfying surge of boost, but all that extra oomph comes at a cost—they can wear out from excessive friction and heat, usually from oil starvation or dirty oil mucking the turbine housings.
Some turbos also fail prematurely, although this is rare in modern vehicles. We mostly see turbo problems in cars over ten years old and modified vehicles that are remapped (that extra performance equals extra wear and tear).
Here are the most common symptoms of a bad turbo:
Power Loss
A gradual or sudden loss of power is the most noticeable indication that your turbo is struggling to operate properly. Other signs of a turbo problem include sluggish acceleration, struggling at high RPMs, and a juddering or jerky sensation through the steering wheel. Most people experience power loss in low gears around town.
Slower Acceleration
Turbocharged vehicles are prized for their ability to accelerate quickly. So, if your ride suddenly seems lazy when you step on it, it's often due to turbo issues. A worn turbo can't spin fast enough to produce the extra airflow needed for rapid acceleration. You may notice hesitation or stuttering, especially when overtaking or merging onto motorways.
Unusual Turbo Noises
Turbos in peak condition have a distinct sound—a soft and steady whooshing noise as they spool up. But as turbos degrade, their sonic signature changes. Listen for a louder, whinier pitch or high-pitched squealing when accelerating. These sounds usually indicate problems with the turbo bearings or housing. In severe cases, you may hear rumbling, rattling, or screeching from a turbo on its last legs.
Excessive Exhaust Smoke
Turbo housing cracks and worn internal seals can leak oil into the exhaust system. Under acceleration, blueish smoke exits the tailpipe as the oil burns off. Blueish smoke is a telltale sign of oil leaking into the exhaust, which leaky valve seals or bad piston rings can also cause. Get your car inspected to diagnose.
Check Engine Light
Modern engines have sensors that monitor performance, including the turbo, so if the pressure, turbo speed, or temperature readings fall outside of normal parameters, the check engine light will activate (and sometimes intermittently).
An illuminated CEL doesn't always mean imminent turbo failure, but it's best to have the fault codes read by a mechanic. For example, we can pinpoint which component is struggling before it leaves you stranded.
Burning Oil Smell
If you detect an acrid burning smell wafting from the exhaust, oil is likely leaking internally and getting super-heated by the turbo.
Worn piston rings, degraded valve seals, or a cracked turbo housing allow motor oil to seep past and burn off. You may notice the smell is strongest after long boost periods under hard acceleration. Don't ignore this—it's the telltale odour of a turbo in trouble.
What Causes Turbos to Fail?
- Poor lubrication - Turbos rely on a steady flow of clean oil (easy to maintain with annual servicing) to stay cool and spin freely. Sludgy oil clogs oil passages, and low oil levels accelerate wear on components.
- Foreign object impact - Turbos inhale a massive volume of air, and sometimes debris gets sucked in, damaging the delicate fins and bearings.
- Oil contamination - Coolant or fuel can leak into the oil pan, contaminating the oil supply and creating an oil mix that doesn’t lubricate effectively.
- Excessive exhaust temperatures - Extremely high temperatures in the exhaust system break down turbo lubricating oil and cook the internal bearings.
- Wear and tear—Turbochargers can last a vehicle's lifetime, but this is the exception, not the rule, because they degrade from friction and heat, which is why the correct oil and maintenance are crucial for longevity. How hard you drive and the RPMs you hold onto dictate how hot your turbocharger gets.
Over time, these issues cause critical turbo components to wear out or fail outright. Staying on top of oil changes, using the proper oil grade, and having any fluid leaks repaired quickly will help extend turbo life.
Recalls
Many manufacturers have recalled cars due to turbocharger problems. Audi recalled 26,000 S and RS cars in 2022, and BMW did the same in 2010 for 130,000 cars made from 2007 to 2010. If you aren't the first owner, it's worth checking if your car model has had a turbo recall and whether it had a fix.
The Next Steps
If you suspect turbo troubles, don't delay. Degraded turbos can send contaminants, including metal shrapnel, into the intercooler, intake manifold, or catalytic converter, causing far more damage than just a bad turbo.
Sometimes, the fix is as simple as patching an oil leak or replacing a damaged hose that supplies the turbo. Most problems are repairable, although there is a limit—worn internal components usually require replacement.
Turbos are complex components, so the labour to diagnose and replace them is costly. But driving with a sketchy turbo risks catastrophic engine damage, which makes a £1500 turbo replacement seem like a bargain.
Summing Up
Monitor your turbo for any power, acceleration, noise, smoke, and smell changes. These symptoms are like an early warning system for turbo failure. Swift attention and repair can save thousands in preventable damage down the road.
Our fault diagnosis service is a logical first step involving nothing more than an electronic reader and expert interpretation of fault codes.
P2262 OBD-II Trouble Code is one example of such a code, indicating 'Turbo Boost Pressure Not Detected-Mechanical'—usually related to the actuator assembly. Another example is Error Code P0234, ' Turbocharger Overboost Condition'—related to the boost pressure sensor input signal. These codes indicate a problem that needs further inspection. Get in touch if you want your engine and turbo inspected.