Starting the engine (BMW X3 E83)

The engine started and works properly.

1. Before starting the engine, it is necessary to set the gearbox selector lever (automatic transmission) to the "P" position, or to the "N" position if the transmission is manual.

2. It is necessary to check the functionality of the brake booster. To do this, press the brake pedal and start the engine; the brake pedal should move slightly due to the force of your foot; in this case, the vacuum booster is functioning normally. If the brake pedal does not move when starting, it is recommended to contact a service station for a more detailed diagnosis of the vehicle.

3. Modern cars are equipped with electronic control units (ECU), so there is no need to hold down the accelerator pedal when starting. The electronics will automatically increase the engine speed for faster warm-up, then reduce it to normal idle speed

4. When starting, some of the warning lights for individual vehicle systems light up. At this point, a self-diagnosis of these systems is performed; after a few seconds, the warning lights should go out. If any of the warning lights do not go out, you should refer to the "Operating the vehicle" section of this manual or take your vehicle to a service station.

5. In winter, for cars with a manual transmission, to make it easier to start the engine, you must depress the clutch pedal before starting. If a diesel engine is installed, the car may be equipped with a pre-heating system, which turns on automatically before starting, and a special indicator lights up; after turning it off, the engine can be started.



6. It is advisable, after successfully starting the engine, to open the hood and inspect all the main components of the engine to ensure there are no leaks (at the main mating points: cylinder head to cylinder block, oil pan to cylinder block, gearbox to engine). Also check the level of coolant and brake fluid in the expansion tanks. If necessary, top up to the required level.

7. Check the functioning of all elements of the lighting system. If you detect any faults, refer to the "Electrical Equipment" section or contact a service station. The following should be checked:

• a) Headlights (low/high beam headlights/fog lights).
• b) Direction indicators and indicator repeaters (front and rear).
• c) Rear brake lights, rear fog light and reversing light of the vehicle.

The engine does not start, the crankshaft does not turn.

1. Check the battery charge level.

2. Check and ensure that the electrical wiring terminals are connected to the battery properly (see chapter "Vehicle operation"). Also check the wiring terminals for oxidation (clean the terminals if necessary).

3. Make sure that the high-voltage spark plug wires are connected correctly. Also check the wire / coil wires/ignition coils.

4. Check the starting system fuses (see below "Actions in an emergency").

5. Check that the electrical wiring is connected correctly to the starter of the starting system.

6. Check the technical condition of the spark plugs (see the picture below).

7. Check the ignition system fuses (see below "Actions in an emergency").



8. Using a hydrometer, measure the density of the electrolyte in each cell of the battery (see chapter "Engine electrical equipment").

9. Using a voltmeter, measure the voltage at the battery terminals.

10. Check the technical condition of the starter (see chapter "Engine electrical equipment").

The engine does not start, the crankshaft turns.

1. Check the fuel level in the fuel tank. Be careful and cautious, as some models are equipped with electric fuel pumps that are lubricated by the fuel itself. Therefore, when the fuel is completely consumed, the pump will run dry, which can lead to its failure. It should also be taken into account that the low fuel indicator light comes on if there are 5-8 liters of fuel remaining in the tank.

2. Check and ensure that the electrical wiring terminals are properly connected to the battery (see the chapter "Operating the vehicle"). Also check the electrical wiring terminals for oxidation (clean the terminals if necessary). If the terminals are corroded, the crankshaft may turn very slowly and stop.

3. Alternatively, a situation may arise where the engine "picks up" (starts, turns over a few revolutions and stalls), but it doesn't start. The reason may be an air leak in one of the elements of the intake system (see chapter "Intake and exhaust system"). Air leakage is possible from the following points where the intake system elements are connected:

• a) The place where the throttle body is attached to the air duct (towards the intake manifold).
• b) The place where the air duct is attached to the intake manifold.
• c) Connection of the intake manifold to the cylinder head.
• d) Also, on some vehicles, there may be a leak due to a loose intake air temperature sensor.

4. Check the engine management system sensors.



Modern engine management systems use many sensors that read information about certain parameters of a mechanism or system and send signals to the electronic control unit (ECU/ESM/RSM), all this is done to optimize and improve the engine's operating processes. But, there are sensors that, if they fail, will indirectly affect the operation, but the engine will continue to run (fuel consumption will change and/or power will decrease, some interruptions in operation are possible), and the indicator on the instrument panel will light up "CHECK ENGINE" . There are also several key sensors that, if they fail, will prevent the engine from starting, namely:

• a) Oxygen excess sensor (lambda probe). On modern cars it is installed before and after the catalytic converter (see the chapter "Engine management system"),
• b) Crankshaft position sensor (see chapter "Mechanical part of the engine"). It is installed either above the flywheel from the rear of the engine or from the front of the engine.
• c) Mass air flow sensor. It is installed in the air duct of the intake system, in front of the throttle valve (see chapter "Engine management system").

5. In winter (when first starting in the morning after a night in the garage or parking lot) the crankshaft may turn very slowly, which is insufficient to start the engine. The reason could be (provided that all other systems and components are in good working order) freezing of the battery. To warm up the battery, turn on the high beam headlights for 1-2 minutes. Then try starting the engine again. If the engine fails to start, see the possible causes above. If the vehicle is equipped with a diesel engine, a possible cause may be the formation of paraffin plugs in the fuel lines and fuel channels (this violation is typical for cars that are parked for a long time in an unheated parking lot).



6. If the car has been parked outdoors overnight in winter, difficulty starting may occur due to thickening of the engine and transmission oil.

The engine starts, but runs intermittently.

1. Malfunctions in the fuel system (see the chapter "Fuel System"). Malfunctions in the fuel pump may be the cause (Fuel injection pump for diesel engines), air in the fuel lines, contamination of the fuel injector nozzles, heavy carbon deposits on the injector nozzles (diesel engines). All work related to fuel system components is recommended to be performed at specialized service stations.

2. The cause may be an air leak in one of the elements of the intake system (see chapter "Intake and exhaust system"). Air leakage is possible from the following points where the intake system elements are connected:

• a) The place where the throttle body is attached to the air duct (towards the intake manifold).
• b) The place where the air duct is attached to the intake manifold.
• c) Connection of the intake manifold to the cylinder head.

3. Malfunctions of the ignition system (gasoline only). In this case, work related to ignition system elements is recommended to be carried out at specialized service stations. You can check the following yourself:

• a) Correct connection of high-voltage wires. The wires should fit snugly onto the spark plug tips and ignition coils.
• b) The technical condition of the spark plugs and the compliance of the installed spark plugs with the technical requirements of the vehicle manufacturer. Also, by the carbon deposits or deposits on the spark plug electrodes, it is possible to determine what malfunctions have occurred in the engine operation (see picture).

Note: There are two main types of candles: hot and cold.

• c) Check the quality of the fuel being poured.

3a. Malfunction of the fuel injection pump (high-pressure fuel pump), associated with the shift in the start of injection and the timing of fuel injection. The reason may be the displacement of the fuel injection pump drive sprockets (provided that the pump was removed and installed) relative to the drive chain or belt.

4. Violation of valve timing installation. In this case, the engine may continue to operate, but with increased fuel consumption and a significant loss of power. There are many reasons that can lead to such a violation, but there are two main ones:

• a) When replacing the drive chain/timing belt (gas distribution mechanism) a phase shift occurred.
• b) Malfunctions of the electronic engine control unit (ECU).

Note: It is recommended that the above faults be corrected at a service station.

5. Violation of the ignition timing angle setting (see "Explanatory Dictionary"). If the ignition timing has shifted to a later value, then engine misfires may be accompanied by popping sounds in the vehicle's exhaust system, as well as black smoke from the exhaust pipe. In this case, it is necessary to stop the engine as quickly as possible, since unburned fuel in the cylinders will burn out in the catalytic converter, which can lead to its failure. If, when the engine is running rough at idle, you hear popping sounds in the intake manifold, this indicates that the ignition timing has shifted to an earlier ignition zone. Incorrect ignition timing can lead to serious consequences that may arise from overloading individual engine components, units and systems.

6. Problems in the charging system. In this case, in the cabin on the instrument panel, after starting the engine, the indicator about the lack of battery charge will light up . In this case, it is necessary to check the electrical wiring connections to the generator. If the wiring is connected properly, you need to contact a service station.

7. If blue smoke comes out of the exhaust pipe while the engine is running, the cause may be engine oil getting into the cylinders (through the valve bushings or through the piston rings, see the chapter "Engine Mechanical Part"), which causes carbon deposits to form on the pistons, spark plugs and injectors, causing the engine to run rough. In this case, you need to contact a service station to carry out repair work.

For diesel engines:

If black smoke is coming from the exhaust pipe and the engine is running rough, the cause may be a loose valve in the injector nozzle, which leads to fuel leaks into the cylinder.

8. Also, engine performance may be impaired due to decreased compression in one or more engine cylinders (see chapter "Mechanical part of the engine").

(Information taken from this resource «www.bmwman.ru»)