Most GTI turbos that die young aren't defective — they're starved or coked. The turbo spins on a film of engine oil at huge speed and heat; dirty oil, a blocked feed line, or shutting a hot engine straight off cooks that oil into carbon ("coking") that wrecks the bearing. A few habits make a turbo last the life of the car. See Turbo Replacement DIY for when one has already failed
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