What causes a car engine to suddenly stop?

This blog post will answer the question, ‘What causes a car engine to suddenly stop?’, and cover topics like different reasons behind car engine stopping, and what to do if a car engine stops.

What causes a car engine to suddenly stop?

A car engine can suddenly stop due to the following reasons:

  • An overheated engine
  • A clogged catalytic converter
  • Lack of sufficient transmission fluid
  • Ignition-related electrical issues
  • Engine mounting bolts are not tight enough

Different reasons behind car engine stopping

These are the different reasons behind a car engine stalling.

Problems with the fuel system

The fuel system is crucial to keep a car in motion as it provides the raw materials necessary for producing power for the car. Problems in the fuel system include inadequate fuel pressure or a defective fuel pump.

The fuel system should also be thoroughly checked for actual leakage in fuel. Ignoring this issue can lead to inadequate or even improper combustion thus leading to engine stalling.

Defective alternator

The alternator in a car is responsible for keeping the engine charged and providing the optimum voltage. A defective alternator can result in insufficient voltage and can lead to a sudden discharge in the battery. This problem can persist even if a new car battery is installed.

Defective spark plugs

Spark plugs are necessary for igniting the air-fuel mixture inside the combustion chamber and certain defects or a spark loss can result in no ignition and consequently, no power produced.

Spark losses are usually caused by defective coils in the ignition system, and defective distributor caps.

Problems with the different sensors

Car engine sensors display critical information depending on which actions the working condition of a particular system is determined.

The main sensors in an engine are the likes of:

  • Mass airflow sensor(MAF)
  • Oxygen sensor(O2)
  • Throttle position sensor(TPS)
  • Engine coolant temperature sensor(ECT)

These sensors are crucial for engine performance and need to be replaced with immediate effect.

Clogged EGR valve

The EGR valve is also known as the exhaust gas recirculation valve, primarily helps to recirculate the exhaust gases back to the engine combustion chambers. This action helps in reducing the temperature inside the cylinders.

The exhaust gases contain carbon dioxide(CO2), which does not have the ability to take part in the combustion, and thus helps in reducing the temperature.

When the EGR valve suffers from clogging, it fails to recirculate the exhaust gases and thus influences the air-fuel mixture inside the cylinder, which leads to creating less power. This insufficient power produced can lead to engine stalling.

Vacuum leakage

This scenario occurs when excess or unwanted air makes its way into the engine. This results in the air-fuel mixture becoming lean in nature and affecting combustion rates. This usually occurs during the winter months as a richer air-fuel mixture is required for combustion in order to produce optimum power for the car.

Failure of components driven by a belt

Components like the compressor or certain pumps like the steering pump can fail and cause the belt to snap, or even apply excessive loads on them thus stalling the engine.

Problems with timing

In modern cars, timing is a necessity for optimum combustion to take place. Timing chains monitor engine cylinder timing by acting as a linkage between crankshaft and camshaft.

A damaged timing chain can lead to severe damage to the internal components of an engine and can also cause the natural timing of the engine to alter.

What to do if a car engine stops?

The problem can be caused due to issues in the fuel system, faulty sensors, or other electrical equipment like spark plugs. These are the following steps to take in case a car engine stops:

Fuel related issues

These are the following steps to take in case the issue lies within the fuel system.

Fuel filter

A good reason behind fuel system problems is a clogged fuel filter. Therefore, it becomes necessary to replace it. It can be done as follows:

  • Loosen the seals on either end of the fuel lines.
  • Take out the supporting bracket followed by the old fuel filter
  • Install the new filter and screw the bracket followed by the seals on either end of the fuel lines
  • To collect any excess oil, a collecting medium can be placed below the filter

Cracked fuel lines

Cracks in fuel lines result in fuel leaking out before making its way to the engine. A car should never be driven with a leaking fuel line and this must be fixed with immediate effect.

Fuel pump

Fuel pumps are necessary to transfer the fuel for combustion with air in the combustion chamber. Either the fuse protecting the fuel pump is broken or the fuel pump reading does not match the vehicle specifications.

Sensor related issues

Sensors are crucial for optimum car performance as they display critical information about the car’s condition.

In the event of an engine stall, the mass airflow sensor(MAF) and the oxygen sensor(O2) need to be checked for any clogging. They might be covered in dirt or dust and need to be cleaned immediately.

They are responsible for monitoring the volume of air entering the engine for combustion and if damaged, they must be replaced with immediate effect.

Clogging can also be noticed in the car’s catalytic converter, which filters the harmful exhaust gases from the engine and lets out water and carbon dioxide instead. They need to be fixed or replaced immediately as per the requirements.

Electrical issues

Electrical issues can pertain to spark plugs or batteries contributing to engine failure. 

Spark plugs if worn out or old can cause failure in the combustion of the air-fuel mixture and result in misfiring cylinders.

The car battery terminals need to be checked for dirt, debris, or grime buildup and need to be cleaned properly. The alternator also needs to be checked to ensure the optimum voltage is being provided to keep the battery charged.

Research has shown the effect of natural disasters that can potentially cause a car engine to stall.

Conclusion

This blog post answered the question, ‘What causes a car engine to suddenly stop?’.

We understood the various reasons behind a car engine stopping, and also the steps to take to solve this solution. Please feel free to comment on the content or ask any questions in the comments section below.

Frequently Asked Questions (FAQs): What causes a car engine to suddenly stop?

What causes a car to stall when stopping?

The reasons behind a car engine stalling while stopping can either be clogged fuel filters, defective spark plugs, or faulty sensors.

Does stalling damage the car?

A car engine stall does not damage the car in any way, however, it can cause serious problems in the long run if ignored for long.

Can low oil cause car stall?

Driving on an inadequate supply of oil can cause engine stalling and might also seize the engine if left unattended.

References

https://axleaddict.com/auto-repair/Car-Dies-While-Driving-or-at-Idle-Diagnosis
https://mechanicbase.com/driving/car-shuts-off-while-driving/

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