For the E30 A/C system, the main line-fitting O-rings are standard SAE sized. BMW confusingly identifies them by the O-ring’s approximate ID rather than the hose size and does so in mm. Because of the standard SAE sizing, you can can order oring kits much more widely and readily from suppliers like four seasons...
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Step 1: Remove the following fasteners and lift the front bulk head panel up and out. * Some 1987 E30s are equipped with fuel-cooling lines that run across the bulkhead and connect to the A/C lines. Neither the metal lines nor the rubber hoses need to be removed. Simply release the fuel-cooling lines from...
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I’ve found the E30 blower-motor retaining clip to be one of the most counterintuitive—and least documented—parts of the job. Here’s what you need to know. The clip behind the blower motor often falls out when the motor is removed, leaving it unclear where the rear end should attach. Despite appearances, it does not hook...
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Binary comparison of Bosch Motronic 1.3 173 and 525 ECUs, including coolant enrichment, cranking fuel and ignition, and every identified closed-loop idle-control table.
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Summary This is a consolidated index of the BMW service bulletins that apply to the E30, gathered into one page and sorted by system group. It runs to 419 bulletins across 28 system groups, covering everything from connecting rod changes and Motronic fuelling quirks to sunroof adjustment and wind noise. A service bulletin is...
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A practical guide to the full E30 OBC: its displays, sensor inputs, trip calculations, speed warning, temperature alert, CODE immobilizer, coding plug, and built-in checks.
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How the E30 heater and air-conditioning systems route air, control refrigerant pressure, operate the auxiliary fan, and respond to the dashboard controls.
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A system-level explanation of the Bosch Motronic inputs, fuel calculations, ignition mapping, idle control, and emissions hardware used across several BMW E30 applications.
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Aiming the washer jets by eye usually ends up with the water landing too high, too low, or blowing clean over the roof once you are moving. BMW gives eight dimensions for it under procedure 61 71 504 – they locate four spray targets on the glass, two per jet. The method: Transfer distances...
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    Print them on their side: This matters more than anything else here. Do not print these standing up. A 3D print is always weakest at the layer boundaries. Print a pin upright and every layer line runs straight across the shaft, at 90 degrees to the load. Laid on its side, the...
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