Removal & Installation
- Remove intake manifold and cylinder head trim covers as necessary. Disconnect vacuum hoses to intake manifold and throttle body. Drain radiator and remove coolant expansion tank. Remove coolant manifold from rear of cylinder heads.
- Disconnect fuel feed and fuel return lines at engine. Disconnect fuel lines and fuel tank vent line at engine carrier. Disconnect fuel line and wiring from top of fuel vapor canister.
- Loosen hose clamps on idle speed controller and throttle body. Unplug connector on airflow sensor. Remove air cleaner housing/airflow sensor assembly. Raise and support vehicle. Unplug oil level sensor connector. Unplug and remove ignition coils.
- Unplug connectors for crankshaft position sensor and both knock sensors. See Fig 1
. Unplug connectors at intake air temperature sensor, idle speed potentiometer and idle speed controller. Remove Data Link Connector (DLC) plug from bracket. Unplug connector next to DLC.
- Remove bolt securing ignition coil ground wire (near engine lift bracket). Unplug temperature gauge and temperature sensor for DME (Black connector and White connector near engine lift bracket).
- Completely disconnect throttle cable from engine. Remove rear cover from intake manifold. Remove mounting bolts and remove intake manifold. Mark knock sensor connectors for reassembly reference. Remove knock sensor(s) as necessary. To install, reverse removal procedure. Ensure knock sensors are plugged into proper connectors.
Courtesy of BMW OF NORTH AMERICA, INC.