If your 2016 BMW 4 Series has developed a turbocharger problem, the first step should be finding out whether the turbo itself has failed or whether another component is causing the boost problem.
The 2016 4 Series was available with several turbocharged engines. Diesel versions included the 420d, 425d, 430d and 435d, while the petrol range included models such as the 420i, 430i and 440i. The exact turbocharger arrangement therefore depends on the model and engine.
At Bimmer Garage Nottingham, we specialise in BMW and MINI servicing, diagnostics and repairs. For specialist turbocharger reconditioning, we work in collaboration with Midland Turbo.
Common 2016 BMW 4 Series Turbo Problems
A turbocharger or boost-system fault can cause:
- Loss of power
- Poor acceleration
- Excessive turbo lag
- Loud turbo whistling
- Siren-like turbo noise
- Grinding or rattling
- Excessive smoke
- Increased oil consumption
- Boost-pressure faults
- Engine warning light
- Limp mode
These symptoms don't automatically mean that the turbo needs replacing.
BMW 420d Turbo Problems
The 2016 420d uses a 2.0-litre four-cylinder diesel turbo engine, with the later B47 engine appearing in the 2015–2016 period.
If your 420d has lost power or developed a boost fault, possible causes include:
- Turbocharger wear
- Boost leaks
- Intercooler problems
- Turbo actuator/control problems
- Sensor faults
- EGR-related problems
- DPF or exhaust restrictions
A diagnostic scan combined with physical inspection and boost testing can help identify the actual fault.
BMW 430d & 435d Turbo Problems
The larger diesel engines require particular attention because of their more complex turbocharging systems.
The 4 Series 430d and 435d use six-cylinder diesel engines, with the 435d using a twin-turbo configuration.
A problem with one part of the turbocharging system can affect performance and produce symptoms that look like a complete turbo failure.
This is why the system should be diagnosed before ordering replacement parts.
Signs Your BMW 4 Series Turbo May Be Failing
Loss of Power
The car may suddenly feel sluggish, particularly during acceleration, overtaking or climbing hills.
Unusual Turbo Noise
A new or progressively louder whining or siren-like noise should be investigated.
Grinding, scraping or rattling noises can indicate more serious mechanical damage.
Smoke
Blue or blue-grey smoke can indicate oil entering the combustion process. A damaged turbo can potentially allow oil into the intake or exhaust system.
Black smoke on a diesel can have several causes, including insufficient air or boost-related problems.
Increased Oil Consumption
A sudden increase in oil consumption can be associated with turbo problems, although engine wear, leaks and other faults must also be considered.
Don't Automatically Replace the Turbo
A BMW 4 Series with low boost doesn't necessarily need a new turbocharger.
Other components can cause very similar symptoms:
- Split boost hoses
- Intercooler leaks
- Faulty sensors
- Turbo actuator faults
- EGR problems
- DPF restrictions
- Intake restrictions
- Exhaust restrictions
- Oil-supply problems
Replacing the turbo before identifying the actual cause can result in unnecessary expense.
Why Does a BMW Turbo Fail?
Possible causes include:
- Poor lubrication
- Incorrect engine oil
- Contaminated oil
- Restricted oil feed
- Blocked oil drain
- Excessive heat
- Bearing wear
- Foreign-object damage
- Carbon contamination
- Boost-system faults
Finding the cause of the failure is just as important as repairing the turbo.
Can a 2016 BMW 4 Series Turbo Be Reconditioned?
Yes, potentially.
A turbocharger isn't automatically beyond repair simply because it has developed a fault.
Where the turbo is suitable, Bimmer Garage Nottingham works in collaboration with Midland Turbo for turbocharger reconditioning.
The unit can be professionally assessed to determine whether it is suitable for:
- Reconditioning
- Remanufacturing
- Exchange replacement
- New replacement
The correct option depends on the condition of the turbocharger and the reason it failed.
Turbo Oil Leaks
If you discover oil in the intake or around the turbocharger, don't immediately assume the turbo is finished.
A small amount of oil mist can occur in diesel intake systems, while excessive oil accumulation requires investigation.
The turbo, oil feed and drain, crankcase ventilation and intake system should all be checked.
BMW 4 Series Diesel Turbo Failure
If your 420d, 425d, 430d or 435d develops heavy smoke, severe turbo noise, rapid oil consumption or uncontrolled engine revving, stop driving and arrange professional assistance.
A serious diesel turbo failure can potentially allow excessive engine oil into the intake and, in extreme cases, contribute to engine runaway.
Turbo Replacement in Nottingham
At Bimmer Garage Nottingham, we can diagnose your BMW before recommending a turbo replacement.
Depending on the engine, checks can include:
- BMW diagnostic fault codes
- Boost pressure
- Turbocharger condition
- Turbo actuator operation
- Boost hoses
- Intercooler
- Intake system
- DPF/EGR-related faults
- Oil feed and drain
- Oil consumption
- Related engine faults
The aim is to establish whether you actually need a turbo replacement, turbo reconditioning or another repair.
BMW 4 Series Turbo Replacement – Contact Bimmer Garage Nottingham
If your 2016 BMW 4 Series is losing power, smoking, using excessive oil, making unusual turbo noises or entering limp mode, don't ignore the problem.
The exact repair depends on your model and engine, so we don't give a generic fixed price for turbo replacement.
Call Bimmer Garage Nottingham with your registration, engine, mileage and symptoms.
We can assess the vehicle and advise whether the turbo needs repair, reconditioning or replacement.
Bimmer Garage Nottingham – BMW & MINI specialists in Nottingham.
Turbocharger reconditioning available in collaboration with Midland Turbo, where appropriate.