Click Here to Book a Service

Reasons my Car is Stalling

Reasons my Car is Stalling discussed by AP Autocare

There are lots of reasons why your car might stall and they aren't always user error. When your car stalls at a junction or traffic lights it can make you panic trying to get it started again, especially if you have impatient drivers behind you or even worse your car can stall whilst you're driving.  

What happens when your car stalls?

A car engine stalling means the engine has stopped and cut out. If it happens when you are driving your car will first lose its power steering, power and then brakes and stops. If your engine stalls when your car has stopped at a junction or traffic lights then you will often find it hard without the power steering to move it to the side of the road if you can't get it started again. 

Stalling a car can also happen when you don't engage the clutch or change into neutral gear when you are slowing down and stopping. 

What should you do if your car stalls?

If your car stalls then the first thing you should do is put your hazard lights on which will let other drivers know you have an issue. Put your car into neutral and try to restart it. If it doesn't start straight away then leave it 30 seconds and try again. If it still won’t start then leave it a few minutes and try again. If you are on a busy or dangerous road, or on the motorway then you should exit your car safely by using the passenger side door and wait in a safe place behind barriers if there are any and call your breakdown company or the emergency services.

Why is my car stalling?

There are many reasons your car might stall including:

  • You have run out of fuel (petrol or diesel)

  • Fuel mixture which isn't rich enough (this is usually the cause of cold stalling and intermittent stalling and can indicate too much oxygen in the fuel)

  • A faulty fuel pump

  • A faulty alternator

  • A faulty EGR valve

  • A faulty or flat battery

  • A dirty or blocked air filter which is preventing good airflow

  • Low fuel pressure which is an issue if your car only stalls on inclines

  • Problems with releasing the clutch (manual vehicles only)

  • Coolant sensor reading is hot

  • Ignition issues such as loss of spark

Can an automatic car stall?

Yes, an automatic car can still stall. An automatic car uses a torque converter to manage the transmission fluid which keeps your engine running when you are at a standstill and if your torque converter fails then the engine will most likely stall. 

Why do torque converters fail?

Torque converters can fail for many reasons, including:

  • Dirty fluid

  • Engine overheating and problems with the stall speed (RPM at which your torque converter shifts power from the engine to the automatic transmission)

If your automatic car is stalling then you should take it to a reputable garage like AP Autocare who will check your torque converter and conduct a stall-speed test to find out what is wrong with it. 

1.Lack of Fuel

Your car's engine needs fuel for it to run effectively and a lack of it will mean your engine will stall or not start at all. When you run your car low on fuel regularly it can lead to a clogged fuel filter where the debris and dirt gets sucked from the bottom of the fuel tank into the filter and this means that even if you have enough fuel it won’t filter through to your car's engine as it should and your car can stall. Your car's fuel filter rests in the fuel line and works by screening out harmful particles like dirt, dust, debris, and rust before they damage your injectors so it is important to not let your car run low on fuel all of the time.

2. Fuel Mixture 

When you are using poor quality fuel your car's engine's combustion process won’t be efficient. If the fuel pump isn't supplying enough quality fuel to the engine, or if the air/fuel mixture is too lean then your car's engine won't produce enough combustion in the power cycle to stay running and will end up stalling.

If you make the mistake of filling your car with the wrong fuel type then it will stall the car and often damage the engine. If you realise you have put the wrong fuel in your car then don’t try to start it but call your local garage like AP Autocare or your breakdown company who will come out and drain the tank for you. Starting your car will result in the incorrect fuel travelling around your car's engine and its components causing damage that will be costly to repair. 

3. Faulty Fuel Pump

Without enough fuel pressure, your car will not run reliably and will often stall. Even if you have low fuel pressure, your car can sometimes run normally on level ground but as soon as you drive up a hill your car will stall as there isn't enough pressure to push the fuel through the system of the car and into the engine. 

4. Faulty Alternator

The alternator in your car provides power to the spark plugs which ignite the fuel in your engine making the car drive/move. When the alternator is faulty it can mean there isn't enough power in the spark plugs to keep your engine running, which can cause it stalling for no apparent reason, either whilst you are driving or when you try to start your car. 

5. Faulty EGR Valve

When the EGR valve in your car is clogged or dirty which they are prone to, it won’t function properly causing many issues including your car stalling when driving, stalling when at a standstill, result in poor fuel efficiency and emit a strong smell of fuel due to excess hydrocarbons which will also result in a failing emission test during an MOT.

6. Battery Problems

When your battery is not providing enough power your car’s alternator has to work harder to keep the engine running. When the alternator overworks it will put stress on your car's engine and this is a reason for it stalling.  

7. Air Filter Problems

Your car’s engine needs air to breathe and not having enough air will lead to it stalling, therefore, a clean air filter is vital for a reliable and efficient running car.  Your car’s air filter needs to be clean to provide your car’s engine with clean air for it to function properly. Your car’s air filter removes contaminants including; dirt, pollen, dust, leaves, and any other debris before they cause harm to your car’s engine and its components. All car’s air filters become clogged over time which is why it is important to have your car serviced regularly and your air filters changed so they allow enough clean air to pass through your car’s engine.

Air filters normally last around 2-3 years and other signs of them needing to be changed are poor fuel economy, your car misfiring, strange engine noises and in newer cars, a dashboard warning light will advise you of this. 

A reputable and professional garage like AP Autocare can easily check if you need new air filters by performing a fuel pressure test on your vehicle.

8. Low Fuel Pressure

Without enough fuel pressure, your car will not run reliably and will often stall or not start intermittently. If you have low fuel pressure your car will often run as normal on a level road but as soon as you drive uphill your car is likely to stall as there isn't enough pressure to push the fuel through your car's system and into the engine. You can try adding some fuel injector cleaner to your fuel tank, however, it's always best to get a reliable and trusted garage like AP Autocare to check what is going in so no further damage is made to your cars engine system and components.

9. Clutch Problems

Manual cars are more likely to stall because of the clutch. If you don’t engage the clutch properly or switch into neutral gear when stopping then your car’s engine will likely stall. If there is a problem with your clutch then your car is likely to stall.  

Ap Autocare are experts in clutches and can easily diagnose if there is a problem with your clutch and provide you with a trusted and competitive quote to get it fixed.

What are the signs of a faulty or failing clutch?

  • Burning Smell

  • Revving & Acceleration are not right

  • The clutch pedal feels loose or stiff

  • Strange clutch noises

  • Changing gear or getting your car into gear Is difficult. If you're able to push your clutch pedal down, but actually shifting into a gear is difficult, it can be due to low hydraulic fluid levels

10. Coolant Sensor 

If the coolant temperature sensor is faulty and tells your car's engine computer that the car is all warmed up when it's not, the computer might then reduce the amount of fuel being pushed into the cylinders, which can cause a cold engine to stall. 

11. Ignition Issues

When you put the key in or press your car to start and turn on the battery sends a low amount of electricity to the spark plugs. This ignites the air/fuel mixture in the combustion chambers, causing a controlled explosion which moves the pistons and when these are in motion the alternator kicks in to keep your car’s engine running. If you have ignition problems then your car may spark and start but then stall.

AP Autocare are experts in all types and sizes of vehicles and will quickly establish why your car is stalling. They will provide you with a competitive and trusted quote and will ensure your car is repaired so it is safe for you to drive. You may not think that your car stalling is a safety issue, however, if you stall on a busy road or motorway then it can be very dangerous. 

About AP Autocare

AP Autocare has been in business for over 40 years and we are proud that we are one of the most reputable and independent Repair, Service & MOT Centres in Bristol as well as being one of Bristol's Largest Independent Multi Manufacturer Specialist.

We are within walking distance from Bristol City Centre and Temple Meads Train Station and are ideal for any Service, MOT, or Repair if you work in the city centre or any of the surrounding areas.

We offer a courtesy car if you need a car whilst it’s booked in with us or we can arrange a lift to work or home after you’ve dropped your car off to us, or a collection and delivery service to ensure that being without a car isn’t an inconvenience for you.

Our team is friendly, professional and we offer highly competitive rates with the skills of a main dealership but without the costs associated with them.

We offer services for all vehicles of any age and size from small cars to light commercial vehicles up to 3.5 tonnes (Class 7).

Our Services include:

  • Diagnostics & Repair

  • Engine Diagnostics & Repair

  • Winter Car Checks

  • Servicing (Annual and Interim Services)

  • MOT’s

  • Bodywork & Paint Repairs

  • Air Conditioning Servicing & repair

  • Tyres & Exhausts

  • Brakes

  • Clutches

  • Remapping

  • Suspension & Steering

  • Welding

  • Battery Testing & Replacement

  • Wheel Alignment

  • Tyre Replacement

  • Remapping

If your car is stalling or won’t start contact us today on 0117 963 8916 and one of our experts will be able to answer any questions you may have and arrange an appointment for you.

Published: Friday 14th August 2020