1982 Mercedes Benz 300SDFACTORY OEM SERVICE PROCEDURE

Gasoline Models

The system consists of a fresh air hose from air cleaner to right cylinder head cover, a breather hose from left cylinder head cover, an orifice and a connection to intake system.

During idle or low speed operation, vapors are drawn through the orifice, into the idle air distribution tubes, then into the intake manifold. Fresh air to vent the engine comes through the air cleaner and right cylinder head cover hose. During high speed operation, vapors pass through hose into air cleaner and are drawn in to be burned.

Fig 1: Gasoline Crankcase Ventilation System
G09315492Courtesy of MERCEDES-BENZ USA
Factory Service Tools

Use the Manual With the Right Hardware

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

Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.

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.