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Home >> Audi >> 1989 >> 90 Base, Standard >> Repair and Diagnosis >> Engine Performance >> System >> System/Component Tests >> Air Induction System >> Turbocharger >> Low Boost Pressure
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Low Boost Pressure

  1. Check air cleaner element for contamination or clogging and clean or replace element as necessary. If turbine or compressor wheels do not rotate smoothly and lightly when turned by hand, replace turbocharger assembly. Inspect for wastegate valve or relief valve which may be left open.
  2. If turbocharger appears to be in good condition, but has low boost pressure, check for the following:
    • Gas leaks in exhaust system.
    • Deformed or clogged exhaust pipe or muffler which may cause increased exhaust resistance.
    • Air leaks from compressor discharge side.