1987 Mercedes Benz 300SDLFACTORY OEM SERVICE PROCEDURE

RECIRCULATION Air Control

Air recirculating valve is opened or closed depending on input signal to EDS control unit to improve burn-up conditions in trap oxidizer. Air recirculating valve opens when engine speed is between 1200-3600 RPM and fuel rack load is less than .35" (9 mm).

Factory Service Tools

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.