BMW 318i, 325, 325e, 325es, 325i, 325is, 325i Convertible 1984–1990 Bentley Service Manual

Published as Bentley Stock No. B390, this service manual covers the BMW 3 Series E30: 1984–1985 318i; the 325/325e/325es range, including the 1988 325; and 1987–1990 325i, 325is and 325i Convertible. The 318i coverage is for M10 engines; M3 and 325ix repairs are outside its scope.

PDF Search, Navigation and Page Count

Search and navigation: An OCR text layer supports searches across the technical chapters, although recognition errors can affect matches. Seventeen PDF bookmarks link to the contents, chapters and index. Small wiring-diagram labels can require zoom.

One printable 554-page PDF contains 15 chapters and an eight-page Section 16 index. The total includes eight opening pages (cover and introductory material, including one blank page), 13 blank chapter dividers, an acknowledgments page and a maintenance-history sheet.

Engine, Drivetrain and Electrical Repair Coverage

Selected content highlights include the following service and repair areas.

• Engine diagnosis and repair: Compression, leak-down and vacuum tests; timing-drive service, valve adjustment, cylinder-head reconditioning, engine removal and internal-component inspection.
• Fuel and ignition: System-specific troubleshooting, injector and pressure tests, ignition timing, ECU terminal checks and Motronic fault-code diagnosis.
• Cooling and exhaust: Pressure testing, radiator, thermostat and water-pump service, cooling-system bleeding, exhaust replacement, catalytic-converter checks and oxygen-sensor testing.
• Transmission and driveline: Clutch hydraulics, gearbox removal, selected manual-transmission overhaul, automatic-transmission testing, driveshaft alignment and final-drive seal service.
• Brakes and chassis: Hydraulic diagnosis and bleeding, disc and drum brakes, ABS inspection, suspension, wheel bearings, drive axles and steering.
• Body and convertible: Interior and heater work, doors, windows, central locking, sunroof, convertible-top frame adjustment and air-conditioning checks.
• Electrical systems: Starting and charging diagnosis, lighting, wipers, power accessories, service indicators, onboard computer, active check control and cruise control.

Written for BMW owners with basic mechanical skills and independent service professionals, with specialist tools and training required for certain operations.

Engine Diagnosis, Mechanical Repair and Cooling

Testing and overhaul: Compression and wet-compression tests, leak-down testing and vacuum-gauge interpretation accompany camshaft, rocker-arm and valve-stem-seal work, cylinder-head removal and reconditioning, and engine removal. Block, piston, connecting-rod, crankshaft and bearing inspections extend into lubrication-system service.

Timing and specifications: M10 timing-chain and M20 timing-belt procedures include camshaft-alignment illustrations. Tables cover valve/cylinder-head dimensions, piston/ring/bore clearances, crankshaft tolerances and compression/vacuum readings. Rotating the crankshaft or camshaft with the M10 chain removed can bend valves.

Cooling and emissions: Step-by-step procedures cover cooling-system pressure tests and bleeding, radiator, thermostat and water-pump work. Fan-clutch and auxiliary-fan checks accompany exhaust-system service, catalytic-converter inspection and oxygen-sensor/heater-circuit tests.

Fuel Injection and Ignition Diagnosis

System selection: L-Jetronic coverage applies to the 318i; basic Motronic and Motronic 1.1 are distinguished for six-cylinder models. Motronic 1.1 coverage includes 325i, 325is, 325i Convertible and the 1988 325.

Symptom charts address no-start, hard-start, cold/warm idle, stalling, misfire, poor acceleration, excessive fuel consumption and emissions. Tests cover fuel-pump relays, delivery, operating/residual pressure, injectors, airflow sensors, throttle switches, coolant/intake-air sensors and idle control, alongside ignition timing/advance and ECU connector-terminal checks.

L-Jetronic/Motronic schematics and baseline electrical tables help select checks for the installed system. Onboard fault-code diagnosis applies to 325i-series models with Motronic 1.1.

Transmission, Clutch and Driveline Work

Manual transmissions: Getrag 240, ZF S5-16 and Getrag 260 coverage includes clutch hydraulics and bleeding, shift linkage, clutch/gearbox removal and installation. Geartrain service covers the Getrag units; ZF S5-16 internal repair is excluded. Cross-sections and exploded shift-mechanism views show the assemblies.

Automatics: ZF 3HP22, 4HP22H and 4HP22EH coverage includes troubleshooting, stall/pressure tests, external adjustments, removal/installation and seals, with a 4HP22 cutaway and schematic. Internal automatic-transmission overhaul is excluded.

Driveline: Procedures cover driveshaft alignment, flexible couplings and center bearings. Final-drive work includes removal, installation and seals; internal differential overhaul is excluded. Tables supply gearbox service limits, adjustments, driveshaft runout and play.

Supporting a manual gearbox by its input shaft can damage the clutch and transmission.

Brakes, Steering, Body and Convertible Systems

Chassis: Brake hydraulics, disc/drum service, alignment, struts, control arms, wheel bearings, drive axles/CV joints, steering racks and tie rods are covered, including power-steering pressure tests and bleeding. Specifications include brake wear/reconditioning limits, alignment data and hydraulic pressures.

An ABS layout supports wiring and pulse-wheel inspections. Specialized ABS diagnosis/repair and SRS service are outside the manual’s coverage.

Body and climate: Procedures cover the instrument panel, interior, heater controls, doors, windows, central locking, sunroof, and convertible-top frame/window adjustments. Air-conditioning coverage provides inspections, specifications and selected electrical checks; most other A/C testing is outside its scope.

Electrical Diagnosis and Workshop References

Circuits and components: Alternator/regulator, battery-drain and starter-circuit tests extend the electrical troubleshooting coverage. Wiring diagrams connect with component-location, connector, ground, splice and relay tables. Voltage, resistance and continuity data support fault tracing.

Workshop use: Descriptions, maintenance schedules, troubleshooting charts and step-by-step procedures support movement from a symptom or failed test to the relevant removal, inspection, adjustment or repair operation. Torque tables, approved fluids and capacities provide the corresponding service references.

Special tools: References include BMW 62 1 120 and 62 1 100 service-reset tools, the 62 1 140 adapter for later 20-pin connectors, the 21 2 060 clutch-wear gauge and 12 6 400 for 318i idle-mixture adjustment.

Edition and safety: Editorial closing was August 1990; later updates and retrofits are not included. This is an independently published Bentley manual; BMW did not review or endorse its contents. Model/VIN identification matters when selecting variant-specific procedures.

Fuel, brake, refrigerant, electrical and under-vehicle work requires the equipment, training and precautions specified in the manual.

A Preview of Valve and Injector Specifications

With coolant temperature below 95°F (35°C), intake and exhaust valve clearance is 0.20 mm (0.008 in.) for the M10 and 0.25 mm (0.010 in.) for the M20.

For the 325i, 325is and 325i Convertible, the injector test table specifies 14.5–17.5 Ω coil resistance at 68°F (20°C).