1986 Mercedes-Benz 300E Service Manual

• Covers the 1986–1988 Mercedes-Benz 300E, including 260E, 300CE, and 300TE wagon variants, detailing the 3.0L 6-cylinder gasoline engine and automatic climate control system.
• Official Mitchell Repair Information Company publication (PN 126-589-10-21-00, copyright 1998) featuring original manufacturer diagnostic data and inspection guidelines.
• Serves as the standard professional reference for M103 engine performance, cooling networks, and HVAC assembly maintenance.
• Delivers extensive technical specifications, vacuum diagrams, and system performance charts across its comprehensive 84-page layout.

Engine and Mechanical Documentation

This technical publication deeply catalogs engine removal, cylinder head, and valve train assembly parameters for the W124 chassis. Mechanics will find exact specifications for engine identification, piston-to-cylinder tolerances, timing chain installation, and camshaft timing. Proper maintenance on the M103 powertrain demands strict adherence to factory safety protocols, especially when securing critical components or handling heavy engine assemblies. To support safe and accurate workflows, the text outlines required specialized tools like assembly fixtures and mandrels for valve guide installation. Torque values for connecting rod bolts, crankshaft damper bolts, and main bearing cap bolts are presented clearly in angle-tightening sequences. Essential data covering engine oil pressure, crankcase capacities, and cooling system specifications is also defined to assist technicians with complex rebuilds and standard service intervals.

Climate Control and Diagnostic Data

The climate control section thoroughly breaks down the electronic control unit (ECU), temperature sensors, and heater valve operation. It includes precise vacuum diagrams for the 300E along with 420/560 models. These schematics map out switchover valve routing and vacuum actuator functions for the dash air doors. System diagnosis is heavily supported through detailed performance tables that list pressure readings and exact outlet temperature ranges. A/C system specifications are outlined comprehensively. Technicians will find R-12 capacity, compressor type, and belt deflection metrics alongside targeted diagnostic procedures for testing the ETR switch and auxiliary fan operation.