Category Archives: Mechanic

Let’s Troubleshoot Car Won’t Start or Turn Over

There are many things under the hood that can keep a car from starting and prevent the engine from turning over. The list below outlines the most common circumstances and tells you what action you can take to try to remedy each situation

The key won’t turn in the ignition: If the key won’t turn in the ignition, it could be for a couple of reasons: Often this happens when the steering is locked by the ignition lock with the front wheels turned aside (e.g. when parking on a hill) or when one of the front wheels is pushed against something (e.g. curb stone). In this case, try turning the steering wheel left and right while gently jiggling the ignition key – this might help to release the steering lock.

Another possibility is that there is a problem with the ignition lock or the key itself. This happens; the key and the lock mechanism wear over time. Try to use a spare key. If nothing works, your local dealer is the best place to call.

No lights on the instrument panel: If you turn the ignition on and no lights come on at the instrument panel means that there is no power coming from the battery. It could be a dead battery or often a bad ignition switch could cause this. Turn the headlights on, if they work, means the battery has power, so the problem could be with the ignition switch or wiring between the ignition switch and battery.

If no lights coming on in the dash and no other electrical consumers work, the battery could be completely dead or there is no connection between the battery and the vehicle electrical system. Check if the battery terminals look tight. If the battery is completely dead, jump starting might help.

“Security” or Key-shaped light stays on or flashes on the dashboard: Many cars are equippedwith an immobilizer or a security system thatallows the engine to startonly if the correct keyisused. You canfind more information about the immobilizer in yourowner’smanual. 
Basicallyitmeansthat an ignition key has a chip insidewith the security code. Whenyou insert itinto the ignition, asensor for the security system reads the code. Normallywhenyouturn the ignition on, youwouldsee a “Security” light to come on for a short time and thenitwould come off. That wouldmeanthat the code in the ignition keyis correct and the car isallowed to start.

If whenyouturn the ignition ON, the “Security” light stays on or flashingmeansthatyour car security system does not recognize the key or thereissomeproblemwithsome part of the security system itself.
Some GM cars, for example, had a problemwith the security system sensorlocatedat the ignition lock. Sometimes, the keyisjustneed to bereprogrammed. You canfind the information how to re-program the key in yourowner’smanual or just Google it. In some cases thereis a simple procedure to re-learn the keythat fixes thisproblem. You alsocantry the sparekey and if nothingworks, your dealer is the place to call. You dealer can check yourimmobilizer and reprogram the ignition keys if needed

Dead battery: A dead battery is the No. 1 cause of a no-start. If the battery is weak, but not totally dead, the starter may turn slowly. You will hear that slow, groaning RRR-RRR-RRR sound. As the voltage drops further, the sound may become a staccato K-K-K. When the battery voltage drops even further, there will be no sound. Even the telltale lights on the instrument panel may dim when you turn the key.

Usually, jump-starting the car will get you on the road, but be sure to find the cause of the dead battery or the situation will recur.

Make sure the clamps can’t easily slip off the battery terminals. Tightening loose clamps may get you on your way.

A weak battery should be replaced, but one that was accidentally drained can simply be recharged.

You can recharge your battery by driving your car around for an hour or so after the jumpstart. If you have one, you can use a battery charger instead.

If your battery is still good, you shouldn’t have another problem with the car starting unless there is another drain on the battery. 

Dirty Battery:Another thing that can stop your car from turning over are the cables that connect the battery to the starter. This is the thickest cable in your car’s electrical system and carries the most current. As such, it is also very susceptible to corrosion.

If your starter cable becomes corroded, it can be cleaned rather easily. Remove each end (one end is attached to the battery, and the other is attached to the starter) and clean the connections with a wire brush. Don’t forget to clean the battery posts at the same time.

Unfortunately, the same fate can befall your ground cables. A corroded or poorly connected ground cable can also prevent the car from starting. Clean ground wires and connections in the same manner.

Alternator: If it is not up to snuff, the battery may not charge. Although the alternator could be the culprit, don’t overlook a worn or slipping accessory drive belt. If the alternator fails or the belt breaks, a warning light illuminates. If the charging system output is poor, there may be no warning light. If you have a gauge on your instrument panel, it should show about 14 volts.

Even a perfectly functioning alternator may not recharge the battery during short trips, especially if the headlights, wipers, heater, radio, rear window defroster and heated seats are on.

Bad Starter: A bad starter may give the illusion of a weak battery if it draws more current than the battery is able to supply. It will spin slowly and draw excessive power. It will make that GRR … GRR … GRR sound, similar to a weak battery.

If you hear a grinding clashing sound like trying to shift with a bad clutch, the starter drive gear or the engine’s flywheel (ring gear) may have damaged teeth.

If the starter does not even turn, its relay or solenoid may be shot or the ignition switch could be the culprit.

Burn Fuses: Only a few cars have a fuse associated with the starting system. However, before you go monkeying around with everything else, check your fuses to be sure it’s not that simple.

Bad Ignition Switch: If your battery checks out, but the starter is still silent, it might be a faulty ignition switch. Turn the key to the on position (not all the way to start).

  • If the red warning lights on your dash don’t light up (and your battery connections are clean), the ignition switch is bad.
  • If they do light up, turn the key to the start position. In most cars, the dash warning lights should turn off at this key position. If you’re not sure, turn on the headlights. When you try to start the car, the lights should either dim considerably or turn off completely. If they do, your ignition switch should be good. If not, the switch will need to be replaced.

Bad Starter Connection: Corrosion can not only keep your battery from connecting, it can also affect any electrical component, especially those like the starter that are exposed to the elements.

If you have someone to help, you can test the connection by holding a circuit tester lead on the wire that engages the starter. This is the smaller of the two wires connected to the starter. Be sure that no part of your body is near the moving parts of the engine—it could still start at any time! Have a friend turn the key and check the current. If you’re getting current to the starter but it isn’t spinning, you will need to replace it.

If your starter spins freely when you turn the key, the problem lies elsewhere. Now you can begin to check the other systems that could keep it from firing up.

Spark plugs: If the engine can’t get a spark, there will be no fire. Although rare nowadays, can cause a no-start. It is easy to forget about the spark plugs when their replacement schedule is 100,000 miles.

Spark is created by your car’s ignition system (ignition means “to ignite”). Ignition system troubleshooting isn’t too difficult and the first thing to check is your coil.

Coil Testing: To properly test your ignition coil, you’ll need a multimeter that can measure impedance. If you don’t have a multimeter, there is an easier test you can perform using simple hand tools. Test your coil and, if it’s bad, replace it.

Distributor Cap: It’s not likely that your distributor cap is the issue, but on occasion (especially during wet weather) a faulty cap can keep your car from starting. Remove your distributor cap and check the inside for moisture. If there is even a drop or mist of water inside, wipe it out with a clean, dry cloth. Inspect the cap for cracks and replace it if necessary. Once it’s dry, it should work.

Coil Wire: The starting problem could also be due to a broken or shorting coil wire. Inspect the wire to see if there are any obvious cracks or splits, then test for continuity using a circuit tester.

Did it start? If it didn’t, it’s time to move on to possible fuel-related problems.. 

Fuel injection electrical connections: There are plenty of electrical connections in your fuel injection system. Each fuel injector has a connector on top. There are connections on the air side of the intake and on the cylinder heads. You should check every electrical connection you can find under the hood to be sure it’s tight.

Fuel Pump and Relay: Even if the tank is full, a weak or failed fuel pump relay may prevent the fuel from reaching the engine. If you listen closely, you should be able to hear the in-tank pump running for a few seconds when you first turn the key to the “on” position before cranking the starter.

To check your fuel pump, you can do a fuel system pressure test if you have the equipment. Since most of us don’t have that type of thing, check the electrical connections first. Test the positive side of the fuel pump for current with a circuit tester. Be sure the key is in the “On” position. If there’s current, move on to the next step. If not, you should check the fuse. If the fuse is good, your problem is the fuel pump relay.

Fuel Filter: If the fuel pump is working properly and fuel is still not reaching the engine, the problem may be a clogged fuel filter. You should be replacing the fuel filter every 12,000 miles or so anyway, so if you suspect it could be clogged, go ahead and replace it.

The items above are things you can easily check yourself and with everyday automotive tools. There are many other elements of your fuel injection system that require electronic diagnosis. Unless you are familiar with this and have the right equipment, it is best to leave this to the pros.

Bad Injectors: A bad injector can throw the entire fuel system off and keep the engine from firing, especially when the engine is warm.

Other Issues That Might Prevent Your Car Starting

With the major systems checked out, there are a number of other things you can check to see why your car won’t start.

Loose Starter: Loose starter bolts will cause it to dance around and wiggle, failing to turn the engine over.

Faulty Cold Start Valve: A failed cold start valve will keep your car from starting when the engine is cold. Don’t let the name fool you, it can even malfunction when it’s warm.

Frozen fuel line: It occurs, but not as frequently where ethanol is blended into the fuel. A can of Iso-Heet in the tank may avoid trouble. To avoid water in the tank, which could turn to ice in the lines, keep your tank at least half-full in very cold weather.

Gas: Is the car out of gas? Yeah, it sounds dumb, but it happens. Check that needle.

Moist air may condense in the fuel tank as the temperature changes and the resulting water settles to the bottom of the tank.

Chipped Flywheel or Ring Gear: Your starter’s gear connects with the gear teeth on your flywheel or ring gear (depending on the type of transmission). If one of these teeth becomes worn or chipped, the starter will spin. In this case, you’ll hear loud screeches, scrapes, squeals, and grinding.

Security system: Finally, the electronics of the security system can bedevil drivers. Trying to start the car with the wrong ignition key can lead up to a 20-minute delay.

Bad ECU or MAF: If your engine’s main computer or any part of the system’s electronics go bad, your car won’t start. Unfortunately, you’ll need to leave this type of diagnostic work to a qualified repair shop.