Leaving a Car Unused – Effects and Preventing Any Issues

There are many reasons why cars are left unused – maybe you’re living away from home, having an extended holiday, or opting for long-term public transport, to name a few. Though leaving a vehicle idle for a short time, such as a week, will not have any negative impacts, there comes a point in time where vehicles are susceptible to damage, which can lead to costly repairs.

We’ll be shedding light on the consequences of letting vehicles gather dust and what you can do to prevent these issues. We also provide suggestions to fix any problems caused by inactive cars, so you can return to the road in perfect condition.

How Long Can a Car Sit Unused?

Modern cars can typically be left idle for three weeks without any risk of minor issues. However, this length of time depends on several factors. These include: the age and condition of the car, the battery’s health, the weather conditions, and whether the car is stored indoors or outdoors.

It’s worth noting that, while modern cars are designed to withstand periods of inactivity, prolonged storage without proper preparation and maintenance can potentially lead to issues when the car is eventually used again.

If you’re asking yourself ‘how long can you leave a car without driving it?’, you may be curious about the legal implications. The fact is a vehicle can be completely inactive, without ever being driven, for any number of years. However a statutory off road notice (SORN) must be made to ensure a car will no longer be taxed and insured and therefore declared fully ‘off the road’.

10 Common Issues From Unused Cars

The extent of damage stemming from inactive vehicles can vary widely, from relatively minor inconveniences to considerable security defects. While numerous issues may arise, we’ve consolidated a list of 10 common problems you’re likely to encounter.

1 – Dead Battery

When a car sits unused, the battery gradually loses its charge due to small electrical drains from systems, like the alarm or onboard computers. Without regular charging from the vehicle’s alternator the battery may eventually lose its ability to hold any charging power, requiring a replacement or, best case, a jump-start to get the automobile running again.

2 – Tyre Flat Spots

When a car remains stationary for an extended period, the weight of the vehicle pressing down on the tyres can cause flat spots to develop, particularly in colder temperatures. These flat spots result in uneven tyre wear and can lead to vibrations and discomfort while driving.

3 – Fluid Degradation

Over time, the various fluids in a car, such as engine oil, coolant, and brake fluid, can break down due to exposure to heat, moisture, and other contaminants. This degradation reduces their effectiveness in lubricating and protecting engine components, potentially leading to increased risk of mechanical damage when the car is restarted.

4 – Fuel System Issues

Petrol can degrade over time, leading to the formation of varnish and deposits in the fuel system. These deposits can clog fuel injectors, fuel lines, and filters, causing ignition difficulties and poor engine performance when the car is brought back into use.

5 – Brake Problems

If a car sits unused with the parking brake engaged, brake pads can stick to the rotors due to rust buildup, resulting in difficulty releasing the brakes and the risk of damage to brake components. This can lead to decreased braking efficiency or even complete brake failure when attempting to drive the car again, needless to say this is incredibly unsafe.

6 – Corrosion and Rust

Outside of corrosion damage to the braking system, moisture can accumulate on the various metal surfaces of the car, causing rust. This can negatively affect structural integrity, general aesthetic appearance and exhaust system functionality, leading to safety hazards and costly repairs.

7 – Electrical System Issues

Electrical components such as wiring, connectors, and electronic modules can degrade over time, especially when exposed to extreme temperatures and humidity. Oxidation can also lead to poor electrical conductivity, resulting in malfunctions of critical systems like lights, sensors, and engine management.

8 – Seized Parts

Lack of lubrication and movement can cause moving parts such as door hinges, suspension components, and the steering system to become stiff. Again, this can be incredibly dangerous, particularly where the steering is concerned.

9 – Interior Damage

Exposure to sunlight, temperature fluctuations, and moisture can cause materials such as upholstery, dashboard plastics, and trim to fade, crack, or warp over time. This weakens the car’s appearance and comfort.

10 – Rodent Damage

Though a rare problem, when a car is inactive, especially in a garage, it can attract rodents looking for shelter. Rodents such as mice can chew through wiring, upholstery, and insulation, causing damage to the car’s electrical system and interior components, as well as leaving behind unpleasant odours and potential health hazards.

How Long Can You Leave a Car Without Starting It? – Effects Over Time

As aforementioned, vehicles should not be left completely idle for longer than 3 – 4 weeks, yet the level of damage caused by cars not being driven varies considerably depending on length of time. As you would expect, the less amount of time a vehicle is stationary, the less problematic any issues will be, i.e. leaving a car unused for 3 months is more damaging than 4 weeks.

So is it bad to leave a car unused? Have a look at the table below to learn the extent of damage at each time period.

Battery Failures Due to Inactive Cars

We established above that battery failure is the most common issue caused by vacant vehicles. So let’s tackle this specific problem in more depth.

A battery concern is problematic because a car cannot function without a battery and, all things considered, it doesn’t take long for the battery’s performance to diminish with a standing car.

How Long Can a Car Battery Sit Unused?

A healthy car battery can typically last for several weeks to a few months without being used, assuming it’s disconnected from any electrical devices. However, if the battery is older or if there are constant electrical drains (such as alarm systems or clocks) it can discharge at a faster rate.

Another factor that impacts how long a battery can last when inactive is temperature conditions. High temperatures can speed up the rate of discharge and lead to faster deterioration of the battery, while extremely cold temperatures can reduce the battery’s ability to provide power.

5 Tips to Keep a Car Battery Healthy

Keeping a car’s battery healthy in a standing car is essential to ensure it doesn’t degrade prematurely. Here are some tips to help maintain the battery.

1 – Disconnect the Battery

If you expect the car to be unused for a long time, consider disconnecting the battery completely. This prevents any drain from the electrical systems in the automobile, ensuring the battery remains charged.

2 – Use a Battery Maintainer

A battery maintainer (or trickle charger) can help keep the battery charged while the car is not in use. These devices provide a low, steady charge to the battery, preventing it from draining completely and maintaining its health.

3 – Start the Car Occasionally

If possible, start the car and let it run for a short period, about 10 minutes or so, every couple of weeks. This helps keep the battery charged and prevents it from losing its charge completely.

4 – Store the Car Properly

If storing the car for an extended period, ensure it’s parked in a dry, cool place away from direct sunlight. If stored outside, consider using a car cover to protect it from the elements.

5 – Inspect and Clean Battery Terminals

Ensure the battery terminals are clean and free of corrosion. Dirty terminals can interfere with the battery’s ability to charge and discharge properly.

8 Methods to Prevent Damage from Unused Vehicles

Now we know how to prevent battery problems due to dormant vehicles, let’s see how we can avoid the other issues that were highlighted above. If all the following factors are taken into consideration, then it’s far likelier that vehicles will remain in good condition, even if they are immobile for a long time.

1 – Maintain Tyre Pressure

To avoid tyre flat spots, it’s crucial to keep your tyres inflated to the recommended pressure levels. Flat spots can develop when a car sits in one position for an extended period, causing uneven wear and potential damage to the tyres. Additionally, consider moving the car slightly every few weeks to shift the contact points on the tyres – this simple action helps distribute the weight evenly across the tyre surface, minimising the risk of flat spots forming.

2 – Fuel Stabilisers

Before leaving a car unused for an extended period, add a fuel stabiliser to the petrol tank. Fuel degradation is a common issue when cars sit idle for too long, leading to starting difficulties and potential damage to the fuel system. A fuel stabiliser helps prevent this degradation by maintaining the chemical composition of the fuel and keeping the fuel system clean.

3 – Appropriate Parking

When parking your car for a long time, taking extra precautions can go a long way in preserving its condition, especially concerning the transmission and overall stability. For example, engaging the handbrake and leaving the car in gear prevents it from rolling, reducing stress on the transmission components. Additionally, placing a wheel chock under the tyres further enhances stability and prevents unintended movement.

4 – Regular Inspections

Regular inspections are vital for ensuring that your parked car remains in good condition. Checking for leaks, corrosion, or any signs of damage allows you to address issues promptly before they escalate into more significant problems. By staying proactive with inspections, you can identify and resolve issues early, ultimately saving time and money on repairs in the long run.

5 – Clean the Vehicle

Before storing your car, giving it a thorough clean is essential for protecting both its exterior and interior surfaces. Dirt, grime, and contaminants can accumulate over time, leading to paint damage and deterioration of other materials and by cleaning your car before storage, you create a protective barrier against these harmful elements, preserving its appearance and structural integrity.

6 – Check Fluid Levels

Ensuring that all fluid levels are topped up helps prevent any potential issues caused by lack of lubrication. This includes engine oil, coolant, brake fluid, and any other essential fluids specified by the manufacturer. Proper lubrication prevents friction and wear on parts, reducing the risk of damage and ensuring your car remains in optimal condition whilst idle.

7 – Park Indoors

Parking your car indoors provides significant protection against environmental factors that can damage its exterior and interior. Exposure to extreme temperatures, sunlight, and precipitation can cause paint fading, interior deterioration, and rust formation on metal surfaces. By storing your car in a garage or covered area, you shield it from these elements, extending its lifespan and reducing the need for costly paint repairs in future.

8 – Rodent Protection

Parking inside does unfortunately encourage rodent infestation. To deter rodents, keep the car’s interior clean, remove any food sources, and consider placing rodent repellents such as traps in and around the vehicle.

Reviving a Car After it has Been Parked for too Long

If preventative measures have not been taken to avoid damage left from an unused vehicle, fear not, there are two core things you can do to ensure your car performs to its best, even after damage has occurred.

Check Brakes

Most importantly the brakes must be checked for proper function and inspected for any corrosion damage. The braking system is critical to the safety of a car, so if they are not in perfect condition, a brake repair is necessary.

Start and Run the Car

If the brakes are in a sufficient state it’s advised to start the car’s engine and allow it to warm up and then drive the car, only a few metres, to address any other issues. Don’t move the vehicle off the drive or onto a road with traffic, as it could be unsafe to drive. If any defects are discovered in this testing phase, then a car repair specialist must be contacted to fix any vehicle damage.

Professional Vehicle repairs with The Bodyshop

If your car has been left standing in Essex or London for a considerable time and there are signs that it needs some repair work, contact our friendly team at The Bodyshop. From aesthetic damage to mechanical issues, our mechanics have the experience and tools to remedy any defects promptly, ensuring you return to the road safely.

If your car has been idle for a long time and you’re unsure if it’s safe to drive, we can also carry out free inspections and advise on any repairs. Reach out to our workshop in Ilford to find out more.