You skipped that second cup of coffee. You are running late. To make matters worse, your car won't start. Why? What can you do?
No-starts fall into two basic categories:
1. The engine will not crank or cranks slowly
2. The engine cranks, but does not run
No or low cranks
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 you will repeat this drill soon.
Make sure the clamps can't easily slip off the battery terminals. Tightening loose clamps may get you on your way.
If the clamps are secure, the battery likely needs a jump. Know the proper way to jump-start a vehicle. Making the wrong connections can cause sparks. Improper polarity may also damage either the donor or recipient vehicle. Learn the proper sequence of connecting and disconnecting the cables as well as where the clamps should be attached.
Some high-end jumper cables (also called booster cables) are designed to prevent inadvertently connecting them wrong.
Choose heavy gauge cables. The lower the gauge number, the heavier the cable. Cheap cables may not be able to carry the electrical current to start the stranded car. The insulation on them may even melt.
Just because you had to jump the battery, it may not be shot. Sometimes it is as simple as charging the battery and cleaning the battery terminals and cable clamps. Corrosion causes resistance, not only to starting, but also to proper charging as the car is running.
Bad positive battery cable connections at the power distribution center (usually that fuse block under the hood) or negative connection (usually to a bolt on the engine or body), mimics dirty cables and terminals. The cables should be removed and their connectors cleaned.
If you have doubts about the battery's condition, have it tested. With today's hand-held testers, the job only takes a couple of minutes. Many auto parts stores and some repair shops offer free testing. They will not only check the battery condition, they will test the charging and starting systems all at the same time.
Replace the battery if it is marginal.
Be sure to buy the right one for your vehicle. Some cars, such as BMWs, require pairing the replacement battery with the car's computer so it can recognize the new one. Many cars can lose electronic memories, ranging from radio presets to power window operation, if the system is not kept alive during a battery swap.
If the alternator is not up to snuff, the battery may not get charged. 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 will illuminate. If the charging system output is only 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 turned on.
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 nasty 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.
Occasionally, the key will not turn in the ignition switch. As an anti-theft feature, the steering wheel locks when the key is removed. Sometimes, the wheel moves back against the locking pawl, preventing you from turning the key. Try nudging the steering wheel left or right as you turn the key.
Cranks, doesn't run
If the starter cranks the engine normally, but the engine refuses to run, the battery, starter and alternator are probably fine. The cause lies elsewhere.
Is the car out of gas? Yeah, it sounds dumb, but it happens. Check that needle.
Even if there is plenty of fuel in the tank, a weak fuel pump 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.
Frozen fuel line
Frozen fuel lines still occur, but not as frequently where ethanol is blended into the fuel. A can of Iso-Heet added to the tank may be like a tonic to prevent problems. To avoid water in the tank, which could turn to ice in the lines, keep your tank at least half-full during very cold weather.
Moisture in the air may condense in the fuel tank as the temperature changes and the liquid water then settles to the bottom of the tank.
Secondary ignition system problems, 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.
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.
Similarly, remote keyless entry and remote starting devices have been known to create havoc. Proximity keys have a way of going missing, such as leaving them in another jacket or purse, which may turn your morning into something like a scavenger hunt.
Ultimately, you may have to resort to your telephone. First, to call your boss. Second, to call for road service. Keep in mind, however, that you may be in for a long wait on some foul, freezing morning. Take comfort in knowing that you are not alone, then enjoy the comfort of another cup of coffee.
Bob Weber is an ASE-certified master mechanic and Motormouth columnist.