Background
The turbo is a marvel of technology - it allows more performance to be extracted of an engine with better fuel economy. BMW has been making turbo engines for decades, many under their TwinTurbo (N54) or TwinPower Turbo (N55) branding. The downside is that a turbo is a wear item - due to its construction and delicate parts, it will need to be replaced eventually.
The Issue
The parts that generally fail are the bearings, the wheel, and the shafts. You see, the turbo spins are very high speeds all the time, so naturally those internal parts are subject to tremendous wear and tear.
Popular BMW Models With a Turbo
Most 4, 6, and 8-cylinder BMW engines have a turbo, including:
- N20/N26 4-cyl engine used in many X1, X2, X3, 2, 3, 4, 5, Series.
- N55 6-cyl engine, widely used in many 1,2, 3, 4, 5-Series cars and X3, X5 SAvs
- N63 V8 engines used in X5, 6, and 7-Series
Symptoms of a Failed Turbo
- Diminished performance - you'd feel the car is lethargic, especially at higher RPMS
- A check engine light on, either sporadic (when the turbo begins to fail) or permanent (when the engine computer detects a certain number of failure events during a specific timeframe)
- Code P0299 stored in the engine computer (PCM - Powertrain Control Module). This can be read by any generic scanner. A more sophisticated scanner will give a sub-code.
