Before we get into the most common problems as to why your car isn't starting, lets have a look at what your car actually needs in order to start:
- A battery with enough power to turn the engine over fast enough to start. Even if your lights turn on and your radio turns on, it doesn't mean your battery is charged.
- A good starter strong enough to turn the engine over fast enough to start. If when you turn the ignition it just clicks, your starter could be dead.
- A engine in good mechanical shape with the correct valve timing and compression. In other words, an engine that works
- Proper fuel air mixture delivered to engine by the carburettor or fuel injection system. As long as you don't have a leak somewhere or some serious engine problems this one is easy.
- Proper spark of high enough voltage across good spark plugs. This spark must happen at the correct time. If you haven't replaced your spark plugs in the last 5 years, thats a bad thing.
The most common problems :
Problem: Starter turns engine slowly: dim lights , radio probably still worksDiagnosis: Dying battery. Hardly anyone takes notice of their battery, myself included. Hence it always catches you at the worse time.Solution: You can try to push start a manual car (won't work for an auto obviously). You can try to recharge the battery, this works if all the battery water hasn't evaporated or if the battery hasn't died completely. You can check the battery cables and make sure that they are not loose, alternatively, the cable heads can be sanded down to get rid of all the dirt and grease that is stopping proper conduction.You can get RACQ (or your equivalent Road Side Service) to come out and give you a quick charge, which might fix the battery once it has been filled with distilled water, or at least get it started so you can get home or to the mechanic to fix it later.
Problem: Starter doesn't operate; no sound from engine, lights and radio don't work at all.Diagnosis: Your battery is deadSolution: Yep, you know what todo. RACQ will be able to swap the battery for you and this is the quickest solution. If you don't want to pay the extra $30-40 or so for a battery from RACQ and can wait. Then you can swap the battery yourself. This is a relatively easy job, just make sure you don't let the wires touch, you don't want to cause more problems.
Stater Motor Problems
Problem: Clicking noise when ignition key is turned to start position. Starter does not operate but lights and radio still works.Diagnosis: Starter motor problemSolution: This is not the best of problems when you need to be at work in 30 mins. Usually you have to get the starter motor replaced, although sometimes (rarely) there can be a stuck gear in the starter. So you can try (in a manual car) to rock the car a little in top gear with the handbrake off. Alternatively if you can locate the starter motor, you can try tapping it with a spanner, a bit draconian I know, but it might also help. Most likely though, you will need to call a mechanic.
Faulty Ignition Switch
Problem: No sound from the engine, while the radio and lights still work.Diagnosis: Faulty Ignition switch, wiring, solenoid or starter motor.Solution: Unless you want to find the solenoid and make sure its got no loose connections, your best of calling a mechanic or getting the car towed.
Starter Motor Turns Engine but Engine doesn't start
Problem: You can hear the starter motor turning the engine but the bloody engine wont actually start!Diagnosis: Most often, you are out of fuel! Yep, that sucks doesn't it? But hey at least its a cheap fix, sortof. Maybe your not out of fuel? Maybe your fuel hose is broken. However somtimes, in older cars you can have Moisture or disconnected/loose wires in the ignition system.Solution: Open the fuel tank and shake the car, if you can't hear any fuel at all, and if the fuel gauge says your empty. Then yes, you need fuel. However if you are sure you got fuel in the car, you can try disconnecting the spark plug leads wipe them dry cloth or paper towel. clean the top of each spark plug before putting it back in place. Nevertheless, unless your desperate and don't value your clothes, I would recommend calling RACQ.
Engine Flooded with Fuel
Problem: You can hear the starter motor turning the engine but nothing happens and after a while, you can smell the petrol in the airDiagnosis: The engine is flooded with Fuel, mostly happens to old cars without Electronic Fuel Injection.Solution: You can wait and let the petrol evaporate (watch your money evaporate) and try again, but most likely, you will need to call a mechanic.
Engine won't start when its wet or damp
Problem: Car won't start in damp or rainy conditions, or you drove through a puddle and the engine died on youDiagnosis: Could be a faulty distributor cap or bad spark plug wires. Could also be that the inside of the distributor cap is wet you can open it up and dry it.Solution: If the cap or the wires are faulty you will need to replace them.
Engine won't start when its really cold
Problem: Engine won't start when its really cold. Though it probably never gets THAT cold here in Australia, this might still happenDiagnosis: Possible fuel injection problem: Electornic Fuel Injection (EFI) system needs to be looked at by a mechanic. Could also be a problem with the cold start injector or Coolant Temp Sensor.Solution: Need to call a mechanic for this.
Engine won't start when its hot
Problem: Engine won't start when its hot.Diagnosis: Possible fuel injection problem: Electornic Fuel Injection (EFI) system needs to be looked at by a mechanic. Could also be a problem with the cold start injector or Coolant Temp Sensor. Could also be a vapour lock or a problem with the injection module or EFI overheatingSolution: Need to call a mechanic for this, who will need to replace the parts. Alternatively you can open the hood and let the car cool down for a while then try again.
Engine turns over slowly when its hot/warm
Problem: Engine starting very slowly when its hot or warmDiagnosis: Problem can be that you have fuel in your oil or your oil is too thin. Can be a battery problem (weak / dead / loose cables) or starter motorSolution: If it is the oil, you will need a new oil filter and new oil! If its a battery you will need to have that fixed, or jump start the car and if its a starter motor, you will need a new one.
Well that's it for now, if you notice any faults or have any more to add please do so by leaving a comment.