1991 Mercedes Benz 350SDFACTORY OEM SERVICE PROCEDURE

Gasoline Engine

Perform gasoline engine compression check with engine at normal operating temperature, distributor inductive pick-up Green cable disconnected at EZL control unit, all spark plugs removed, and throttle wide open. Ensure battery and starter are in good working condition for proper compression results. Crank engine at least 8 revolutions per cylinder. Record pressure readings.

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.