My car turns off by itself when stationary: what is the cause?
There are many causes that can explain why a car turns off when stopped. Mechanical, electrical or electronic, whatever the precise reason, it seems to be a problem that is observed much more than we think, even in modern cars.
Of course, these causes can be many and varied. However, here are some ideas that could help you better understand why your car turns off by itself when stationary.
Vehicle turning off when stopped: symptoms to watch out for
First of all, it is essential to differentiate between a car that turns off when stationary and a car that won’t start after a more or less long break. While some causes overlap, others may be more specific.
In the case of cars that turn off when stopped (red light, stop sign, pedestrian crossing, etc.), without saying that there are always signs warnings before this happens, in the majority of cases, we can still report certain manifestations – noises, shaking, smoke – which could alert you to an imminent shutdown!
- For example, thick black smoke coming out of your exhaust would be typical of a clogged diesel particulate filter. The latter is supposed to clean itself at regular intervals, but it happens that it is too loaded, and that said cleaning is not carried out optimally, leading to too high a back pressure of the exhaust gases, and therefore stopping the engine. The solution? Replace it!
- Jerking when accelerating ? Power problem! In this situation, it is the fuel pump that could be blamed. This has the function of injecting the right quantity of fuel into the engine. If it does not work well, the fuel transition is not ensured, the engine is no longer properly supplied, and ends up stopping. But the cause could also come from a fuse or a fuel pump relay. To be sure, an appointment with your mechanic is necessary.
- You hear your engine whistle? This is often a sign of an intake leak or a leak in the turbocharger charge air system. If this is too high, the engine control unit injects too much fuel, and the air-fuel mixture cannot be ignited by the plug .
Unfortunately, not all causes of downtime can be seen in advance. Some occur without warning, hence the need to inspect or have your vehicle inspected regularly.
Other ideas to explain why the engine stopped
Mechanical problems
You could indeed detect an abnormal functioning of your car, but in many cases, the problem is more subtle and requires greater knowledge of its components.
- Often cited as the number one cause of a car shutting down when stationary: the alternator. If this part is defective, it can no longer supply the car’s components with electrical current. The battery can then take over, but not indefinitely! Bottom line? You will need to replace the alternator and your battery.
- Engine sensors should also be considered. Indeed, modern cars are very dependent on it ; unfortunately, they are not foolproof and may sometimes not work properly. Again, there is a risk of having a faulty fuel mixture, and if the engine is not supplied with the ideal mixture, it will shut down.
Electronic or electrical problems
Mechanical problems are not the only ones responsible for an engine shutdown, rather see the consequences of electronic or electrical problems:
- If the wear of a circuit or component is marked – in particular that on a computer – the electronic or electrical circulations can be disturbed and result in the engine stopping. A short circuit is also possible and could damage the entire system.
- In this category, we can also talk about the motor service box or the BSI box which have been widely talked about on certain brands of cars, and the replacement of which can be more time-consuming and laborious than that of more common defective parts.
- Let’s also not forget to mention Delco’s ignition coils and head for gasoline cars only.
Other problems can also have a much simpler, but equally damaging, explanation, such as choosing the wrong fuel, lack of fuel, or even a dead battery. Although rarer, the Neiman contactor could also be suspected. Designed to protect cars from theft, a malfunction in it can actually cause the engine to stop, or even the steering wheel to lock.
Repair of a vehicle whose engine stops by itself
As you can see, there is no shortage of causes when looking for the reason behind a car that turns off when stopped. The resolution of some is accessible to the most experienced amateur mechanics, others absolutely require the intervention of a garage.
But to guarantee complete safety and hassle-free repair, you won’t find better than a professional. Yes, parts may only require simple replacement, but it is not impossible that a defect – which initially seems small – is in fact the tip of an iceberg that is beyond your skills. And when it comes to car safety, all precautions are necessary, even if they may come with a certain price.
In order to have the service that combines confidence, reliability and controlled cost, you can rely on Trans-Mico Automotive. Since 1979, the company has acquired a serious reputation in the repair and maintenance of all types of vehicles. To keep track of yours, you now know who to rely on.
Sources :
- Carly. La voiture s’arrête en cours de route ? Les causes les plus fréquentes. [Does the car stop en route? The most common causes.] 2022.
- Fiches Auto. Moteur qui se coupe en roulant? [Engine cuts out while driving?] 2016
- Motor Integrator. La voiture s’arrête en cours de route : les causes les plus fréquentes. [The car stops while driving: the most common causes.] 2022.