It’s not always easy to start an old car that has been parked for a long time and get it back into running condition. Engines are run on a regular basis, and the longer they sit idle, the more they can create problems you’ll have to deal with later.
But it’s not impossible to start. Every engine is different, and there are some common techniques to get the engine running again.
Lubricating engine
Since the engine has not flowed any oil for some time, it needs lubrication.
There are two ways to get the engine running. In some cars, you can flip the engine over using a socket wrench on the crankshaft nut, or you can connect the battery to the ignition. If the engine turns over after rotation, then it may start after replacing the spark plug. If your engine has a carburetor, it is recommended to spray starting fluid into the carburetor to help burn.
Replace liquids and filters
One way to start an old engine is to make sure the fuel, oil, and engine coolant are all flowing properly. Common petroleum fuels have a shelf life of three to six months. If left for longer than the shelf life, it is easy to have problems in the fuel system.
Gasoline is a highly refined product that evaporates and burns easily. In addition to evaporation, a process called oxidation can occur when the chemicals in the gas mix with oxygen. This creates deposits in the gas that can clog fuel lines, fuel filters, and carburetors or fuel injectors.
To start an engine that contains old gas, you may need to pump fresh fuel into the system from an external source. You may also need to completely remove old gas from the tank and fuel line before attempting to start the engine. Fuel filters and injectors that have been out of service for months or years may need a good cleaning, or a complete replacement.
Check electrical system
When a battery isn’t being used, the chemical reaction in the battery breaks down and causes it to lose its energy. If the battery sits long enough it will be ineffective for starting up the engine. Corrosive green slime can also take over the battery’s terminals. If more than a little corrosion is present, that’s a sure-fire sign it’s due for replacement. Also be sure to clean from your car’s wiring contacts before installing the new battery. Another product great for car storage is a battery tender. This device provides a small, constant charge to the battery, which prevents it from draining and maintains electrical component health.
In addition to checking the battery, inspect the ignition coils and coil wires. Use a multimeter on the coil to see if the resistance reading matches the recommendation for your vehicle. If it doesn’t, then the coil may be bad. If the coil and its wiring work, use a current reader to see if the starter motor is receiving a current. Corrosion or bad wiring can inhibit the starter motor and prevent the engine from firing up. If the starter motor gets enough current and still doesn’t engage, then it may need a rebuild or replacement.
Check for vacuum leaks
When the engine is left on for a long time, the hose may degrade and crack. A few small leaks won’t stop your car from starting, but a big leak or too many small leaks will. The most effective way to determine if you have a vacuum leak is to use a smoke generator, which creates smoke in the engine and you can see where the vacuum leak is coming from in each hose.
Older engines can also have compression leaks in their cylinder heads. Low compression can prevent fuel from burning in the chamber and prevent the engine from starting, so a compression test at a local mechanic is a must.
Replace the timing belt
The timing belt or chain is the part of the engine that keeps the camshaft, distributor, crankshaft and piston in sync. When the timing belt breaks or is damaged, it may prevent the engine from starting.
Care and maintenance
Regular maintenance is the most important thing for mechanical health, and neglected engines require more care. If your car has been parked for a few months, it may just need to change the fluid and filter to run properly again. If it hasn’t been used for years or even decades, more repairs are needed.
If you’re dealing with an antique engine that hasn’t run in 40 years, the safest bet is to have a professional tear it down and inspect each component before it even starts. They’ll be able to check the block for warpage or scoring, replace bearings and gaskets, and clean out carbon deposits. A full engine rebuild will be an expensive operation, but it’s really the only way to be sure an old car will run like new.