Turbo cleaning and replacement

The turbocharger — the most expensive little accessory

A turbocharger is an exhaust-driven compressor that forces extra air into the engine, increasing both power and torque. It sits in the exhaust manifold and spins at over 200,000 rpm — i.e. it is under extreme stress. When something fails you usually notice quickly: loss of power, blue or black smoke, loud rattling or whistling noises, or oil leaks. We diagnose and repair turbos on all petrol and diesel cars, and often save the turbo before a full replacement is needed.

Common turbo faults

Bearing damage is the most common fault — turbo bearings are lubricated and cooled by engine oil, and if the oil is old, low or dirty the bearings can be torn. The symptom is a rattling noise that varies with boost pressure. Oil-channel blockage happens when soot or oil coke clogs the small channel that feeds the turbo bearings — leading to total turbo failure over time. A defective VGT (Variable Geometry Turbo) mechanism is typical on diesels: the vanes that regulate boost stick in soot, causing power loss and a fault code. Cracked compressor blades can occur if foreign objects (screws, plastic, ice) are sucked into the intake. Worn seals leak oil into the intake or exhaust — the symptom is blue smoke on acceleration or oil loss with no visible drip.

Symptoms to react to

The key symptoms are: power loss and poor acceleration (turbo can't build enough boost), blue or black smoke from the exhaust (oil leaking past seals), rattling or whistling (bearing damage or VGT issue), and oil leaks around the turbo housing. If the check-engine light comes on with these symptoms, the turbo most likely has a fault that needs to be fixed. Continuing to drive a defective turbo risks pieces breaking off and being sucked into the engine — at that point we're talking engine overhaul rather than a turbo job.

Cleaning vs replacement

For many faults (especially soot-coated VGT mechanisms or lightly worn seals) we can clean the turbo and restore function. This requires removing the turbo, ultrasonic cleaning of the actuator mechanism and checking bearing clearance. If bearings are torn or blades damaged, the turbo must be replaced — either with a new original, a new aftermarket unit, or a remanufactured turbo. A remanufactured turbo (from a quality-assured rebuilder) often costs half of new and lasts just as well — we recommend this where available for your car.

Prevention — how to extend turbo life

The most important thing is regular oil changes with the correct oil specification (check the service book). Never use "cheap" oils without approved specification. Let the engine idle for 30 seconds after hard driving before shutting it off — the turbo is still red-hot, and oil that stops circulating coke-bakes onto bearings. Avoid full throttle before the engine reaches operating temperature. Check oil level monthly, especially on older diesels.

Book your repair online or call us on 41 17 32 24.