Almost every car owner has sat behind the steering wheel of a car that won't start. It happens to all vehicles, even the most reliable vehicles like a BMW. It is an unfortunate circumstance that often raises your stress levels, especially if you do not know a car's anatomy. If your BMW won't start and you can hear a clicking noise when you try to turn it on, then first and foremost, try to stay calm.
While staying calm may be a little difficult if you are going to be late for school or work, it will help you focus on trying to solve the problem. If you can find the cause behind why your BMW won't start, then you can explore the best solutions to get it going again.
Continue reading to understand why your BMW is not starting, the things to look for, the possible causes, and even some solutions to get you back on the road again.
What to Check First
It is daunting if you are not a mechanic that knows the ins and outs of a BMW. So far, all you know is that your BMW won't start, and you can hear a clicking noise. Let's get right into what you should check first to help you diagnose your no-start situation.
Below is a basic checklist of what to inspect first:
- Check your fuel. It may sound silly, but you may not have any fuel. Sometimes it is not because you forgot to put fuel in; it could be because your fuel gauge is not working. Your fuel tank may be empty, but the gauge may be telling you there is still fuel. This is a common BMW problem for older models.
- Is the battery okay? A weak, discharged, or dead battery is the most common cause behind a BMW that won't start.
- Check the battery cables. Make sure the battery cables have not corroded and are tight.
- Change the gears. While it sounds strange to be changing the gears in a car that won't start, it could eliminate a possible cause. If you have an automatic transmission, then try starting your BMW in “Neutral.” If the car starts in this gear, then your problem may be the neutral safety switch.
- BMW anti-theft system. Your anti-theft system may have a fault and could be preventing you from starting your car.
Common Causes of Why a BMW Won't Start
Regardless of make or model, some common causes can affect any BMW. These include:
- A discharged or dead battery
- A weak fuel pump or fuel relay
- Electrical problems
- Worn spark plugs
- Bad ignition coil
- Engine temperature sensor / PCM Cooler Sensor
- Damaged key
- A weak battery in your key fob
- Issues with the starter motor
One key factor that you have to work with when trying to decipher the cause is that you can hear a clicking noise even though the BMW won't start.
The clicking sound can help narrow down some of the possible causes. If you hear a clicking sound when turning the ignition, then the following may be a cause of why your engine won't start:
- The battery is dead.
- There could be a parasitic battery drain (the car doesn't stop clicking).
- The battery terminals may be corroded (the clicking noise will be rapid).
- There could be frayed wires or loose battery cable ends.
- The alternator may be damaged.
- The starter motor may be dead or damaged.
- A faulty starter solenoid (you will hear a single click).
- The engine may be damaged or locked up.
Let's take a closer look at some of the reasons above for the clicking sound you get when your BMW won't start.
A Dead Battery
A car uses the battery to provide electrical power to all the electrical components and the entire car itself. If the battery is not charged and the voltage is low, it cannot start the car.
A fully charged battery will carry a voltage of at least 12.65 volts. At 75% of full charge, the battery will give you a reading of 12.45 volts. If you receive a reading of fewer than 12.45 volts, then your battery voltage is low.
Low voltage or high resistance can prevent your BMW from starting. High resistance can cause your battery to heat up and, under the load, the voltage will drop. Basically, this means that you have a dead battery or one that is on its way out.
A symptom of a dead battery is rapid-fire when turning the ignition of your BMW. This could also mean that you have a faulty alternator. The alternator charges the battery when your car is running. A defective alternator will not be able to charge the battery correctly.
If you have repaired or replaced the battery and still hear the clicking sound, then you need to investigate the possibility of a damaged alternator. You may need to budget for the alternator to be repaired or completely replaced.
Parasitic Battery Drain
If your BMW won't start and the battery is older than seven years, then a common problem experienced with older BMW batteries is they have a parasitic draw problem.
If you have determined your battery is in fine working order, then it is likely your BMW has a parasitic battery drain. This problem occurs when there is an abnormal discharge of power once the engine has been switched off.
Even when your car is not running, your battery provides power to the radio, clock, alarm system, etc. While these things are too small to impact the battery, the interior lights, bad fuses, and door lights can drain the car battery. The battery drain caused by these features is known as a parasitic draw or parasitic battery drain.
Even if you remember to turn off the cabin lights, you can experience parasitic draw because of a short circuit or a malfunctioning electrical device that is still working even though it has been switched off.
If you are experiencing this problem, then jumpstart your BMW and get it to your nearest technician to inspect the problem.
Starter Motor Problems
Your starter motor is connected to the car's battery. Suppose the battery is in perfect working order, and you can hear a clicking sound when turning the ignition. In that case, your starter motor may be damaged, or it is not receiving the power it needs from the battery if the battery terminals are corroded.
You can tell if the battery terminals are corroded if there is a green or blue deposit buildup on and around them. You may also notice rust, which indicates corrosion. Luckily, this is an easy fix. You will need to clean the terminals to restore power back to your BMW.
If the battery is okay, and the battery terminals are not corroded, then the problem may lie with the starter solenoid, the battery cables, or with the starter motor itself.
A broken starter is another common problem, especially among older BMW models that have experienced their fair share of mileage. If you hear a loud clicking sound when you turn the ignition key, but your BMW won't start, then there is a high chance that the starter motor or its components are damaged.
Common symptoms of a bad starter include:
- A clicking noise is heard when turning the ignition, but the engine won't crank.
- All the dashboard lights come on, but the engine won't power up.
- The engine will not crank even after a jump start.
- Smoke is coming from the engine.
- Oil has visibly soaked the starter. In this case, your bad starter may indicate an oil leak problem.
If you have smoke coming from the engine, you have exhausted your efforts to turn the ignition. Too many attempts at starting your BMW can cause the starter to overheat and create more electrical problems. If you see smoke, stop trying to turn the ignition.
Below are some causes of starter motor problems:
- Oil leaks.
- Dirty connections.
- Loose wiring or damaged starter circuit.
- Damaged or worn-out components of the starter system.
Sometimes the starter motor armature bushings wear out. This causes the starter armature to rub up against the field coils inside the starter motor. If this happens, the starter motor will crank very slowly, and you may only hear one click when turning the ignition. The solution is to either rebuild the entire starter motor or replace it.
The average cost to replace a BMW starter motor is between $500 and $800. Labor costs could amount to roughly $350, and the parts to replace the old motor with the new one could have you paying between $200 and $400.
With one problem leading into another with the starter motor, sometimes the repair bill is unrealistically high to warrant repairing your BMW. In which case, it may be advisable to hand your damaged vehicle over to Cash Cars Buyer and replace it with a new one.
You may want to consider the option of Cash Cars Buyer if your BMW won't start because of engine damage. The repair bill to either rebuild or replace an entire BMW engine may be extremely expensive. The best option will be to sell the car as-is and take it to a reputable location, like Cash Cars Buyer. You may be surprised at how much money they will offer for your damaged BMW.