A car is built to drive. The moment it stops, it starts to deteriorate, and faster than most people realize. At our workshop we regularly see cars that sat "just a couple of months" and then arrive with a chain of problems that could have been avoided. This article covers both sides: how to prepare a car for extended parking, and what to check when you are ready to use it again.
What Sitting Actually Does to a Car
The battery discharges on its own. Even with everything off, the alarm, relay boxes, and control unit memories draw current. On a battery older than three years, three to four weeks of inactivity are often enough for the voltage to drop below starting level. We wrote about recognizing when a battery is nearing the end of its life in the article on identifying a failing battery. If you are curious about that specific phenomenon of a battery draining while the car sits, check out our piece on parasitic draw.
Tires develop flat spots where they contact the ground. For shorter periods, up to two months, the deformation is usually temporary and disappears after about twenty kilometers of driving. For longer periods, especially on older or cheaper tires, flat spots can become permanent.
Brakes suffer on multiple levels. Discs rust within a few days, but that thin corrosion wears off after several stops. The real trouble is caliper guide pins that seize when the protective grease dries out, and the parking brake that bonds to the discs if left engaged during extended storage. On cars that sat for a year or more, we routinely find completely seized rear brakes. More on when brakes need attention in our article about recognizing brakes due for service.
Fuel has a shelf life, and gasoline and diesel differ. Gasoline begins to lose its properties after roughly three months as lighter fractions evaporate, leaving behind a heavier residue that clogs injectors. Diesel has a different issue, it is prone to bacterial and fungal growth in the tank (so-called "diesel bug"), especially when the tank is half-empty and condensation builds up.
Rubber parts and seals dry out without contact with fluids and without movement. Oil seals, CV boots, coolant hoses, vacuum lines, they all lose elasticity. After extended storage, the first sign is usually a stain under the car or a leak that was not there before.
Rodents are a serious problem, especially when a car sits in a garage or outdoors near vegetation. Mice and rats nest in the engine bay because it is warm and sheltered. They chew through wire insulation, rubber hoses, and even filter elements. At our workshop, we have seen cases where a single mouse chewed through a sensor cable and the owner thought there was an expensive electronic fault. Opening the hood and spending five minutes inspecting would have revealed it immediately.
How to Prepare a Car for Extended Storage
If you know the car will not be driven for a month or longer, half an hour of preparation is well worth it.
On the fuel question, which owners debate endlessly, the answer is simple: a full tank is better than an empty one. An empty tank means more air, more condensation, and more moisture attacking the inside of the tank and the fuel system. A full tank minimizes that. For storage exceeding six months, adding a fuel stabilizer helps, but it is not a miracle cure.
The battery deserves a trickle charger with a maintenance function. If you do not have one, disconnect the negative terminal to prevent parasitic draw, though you will lose radio presets and some control unit memories.
Inflate the tires to the upper limit listed on the door jamb sticker. They will lose pressure during storage, so starting higher gives you a buffer. If storage lasts more than three months, ideally move the car occasionally to change the contact patch.
Leave the parking brake disengaged. Use wheel chocks or bricks instead. A parking brake left engaged during long storage almost guarantees seized rear brakes.
Wash the car before parking it long-term. Dirt, insects, and bird droppings damage the paint if left on the surface for weeks.
Reviving a Car That Has Been Sitting
Before you turn the key, spend twenty minutes on an inspection. You do not need any tools, just your eyes and a bit of patience.
First, open the hood and inspect the engine bay. Look for nests, droppings, chewed cables, or hoses. Next, check the engine oil level and condition by pulling the dipstick and examining the color and smell. If it is black and smells of fuel, changing it before starting is a wise decision. Also check the coolant and brake fluid levels.
Check tire pressures and visually inspect for sidewall cracks. Test the battery with a multimeter if you have one, or simply try to start the engine. If the battery cannot crank the engine, read about how to properly connect jumper cables.
On the first start after extended storage, expect the engine to run rough for the first few seconds. Hydraulic lifters need time to fill with oil. A ticking noise that disappears within ten seconds or so is normal. Brake scraping during the first few stops is surface corrosion being cleaned off, and that is also nothing to worry about.
If the car has been sitting for a year or more, we recommend bringing it in for an inspection before relying on it for daily driving. An oil and filter change, brake inspection, and checking belts and fluid condition is the minimum that should be done professionally.
The "I Will Just Start It Once a Week" Myth
This is advice we hear constantly, and it does more harm than good. If you start the car and let it idle for five to ten minutes, the engine never reaches operating temperature. Condensation in the exhaust system does not evaporate. Moisture in the engine oil is not eliminated. The battery uses more energy to crank the engine than the alternator returns during ten minutes of idling.
The result: damp oil, rust inside the exhaust, and a battery that drains a little more each time. If you cannot take the car for a drive of at least twenty to thirty minutes, it is better not to start it at all. Seriously, short idle sessions without driving are worse than simply letting the car sit.
Note for LPG-Equipped Cars
If the car has an LPG system, close the valve on the LPG tank before parking it for an extended period. The gas system needs an inspection after long storage because the rubber components of the installation also lose elasticity, and the electronics may require recalibration. If the car starts normally on gasoline but has issues when switching to LPG after long storage, that is a sign the LPG system needs servicing.
When to Visit the Workshop
A car that sat for less than three months usually needs nothing more than a battery check, tire pressure verification, and a short test drive. A car that sat for three months to a year deserves an oil change, brake inspection, and a check of all fluids. A car that sat for a year or more is a candidate for a complete inspection before you go anywhere.
Bring it in for a checkup at our workshop in Banja Luka, and if you have questions or want to schedule an appointment, reach out through our contact page.