When the Car Won’t Start – No Spark, No Compression

There are few things as frustrating as getting into a car that won’t start.  Even more irritating is when your engine cranks and STILL will not start!  Before you hit an auto repair shop, let’s examine one issue you may be having. An educated auto owner is better equipped to understand and ask questions about what auto repairs their mechanic or auto repair shop technician advises. 

All engines require satisfactory fuel pressure, a precisely timed spark and regular compression.  If your vehicle’s engine cranks but doesn’t start, you are likely to be experiencing difficulty with one of these.

Engine Cranks – No Spark

Check the spark plug wires.  If they are cracked, wet, or burned it could be causing difficulty with the spark, creating a problem starting the car. Also check that the internal resistance does not exceed specifications, as this will cause the same problem.

You also need to examine the spark plugs.  When you remove the spark plugs, if they are wet they are either not firing or the engine is flooded.  If the plugs’ electrodes have been contaminated with deposits, this can allow the spark to ground before jumping the gap, causing the plugs to misfire.  This will make the vehicle hard to start and cause it to run poorly once started.

If there are cracks or carbon tracks on your rotor or inside the distributor cap, this can be causing problems.  Issues of this nature will allow your spark to short out to ground before ever reaching the spark plugs.

You may be dealing with a bad distributor pickup or faulty crankshaft position sensor. This is what sends the pulse signal to the ignition module or PCM.  Without this, there is no trigger for the ignition coils therefore, the car won’t start.

Another issue that you could have is a defective ignition module.  Since the ignition module is responsible for the firing of the ignition coils, a faulty one can create problems with starting and/or stalling. If you’re having a hard time starting the car, problems with sudden stalling, especially when the engine is hot, you may need to have the ignition module checked. 

Bad ignition coils can affect different autos in different ways.  Its purpose is to create a high voltage that fires your spark plugs.  On vehicles that have a distributor, a bad ignition coil prevents sparking at all of your spark plugs.  If you have a coil-on-plug or distributor-less ignition system, having a bad coil only affects one or two cylinders. While this can create some problems getting the car started, it will be able to run on the remaining cylinders once started.

Engine Cranks – No Compression

Take a look at the timing belt or chain.  A failure or breaking of the belt or chain keeps valves from opening.  Not only will the engine not run, you need to be sure that there are no other damages like bent valves that occurred due to the breakage.

When the engine starts but dies within a couple of minutes, you may have a plugged catalytic convertor.  When the catalytic convertor becomes obstructed, it creates restrictions that then cause your exhaust backpressure to accumulate.

If you have an overhead cam engine, check the camshaft.  If your engine overheats too badly it will warp the head, in turn seizing up the camshaft.  

As a Columbia, SC auto repair shop owner I want to inform drivers (and potential customers) about what their car troubles are and why they happen.  If you have car questions or need to schedule an auto repair or maintenance appointment in the greater Columbia, SC area, Sanford’s is happy to make you their newest loyal customer!

When the Car Won’t Start – By a Pro Mechanic in Columbia SC

 

When the car won’t start, it could be due to a number of things.  The first thing you should do is start to narrow down where your problem may lie.  It doesn’t necessarily take an auto repair professional to get your issue diagnosed or taken care of. 

The Basics

Before you head off to an auto repair shop, you should first understand as much as you can about your problem.  In the most basic description, your car starts because the key turns, creating voltage flow from the battery through the ignition switch, a safety switch, and then to the solenoid or starter relay.  The solenoid or starter relay then routes more power from the battery to the starter, which in turn cranks the engine.  At this point the starter motor spins and pushes the starter drive gear, engaging the flywheel and cranking the engine.

NO-CRANK, NO-START – What is going on?

When the car responds with no crank and no start, there are many common culprits that you will want to check.  To start, a low battery charge or bad battery cables or connections could be to blame.  You should check the battery’s voltage and recharge it or jumpstart the car if the voltage is too low.  You should also inspect the battery cables and connections on both ends.  If there is excessive corrosion on the battery terminals you should clean it off and re-attach the connections securely. 

The next thing to check is the starter relay and solenoid.  Check the voltage, inspect the connections and tighten any necessary wiring issues.  If a relay shows a charge but fails to “click” when you turn the key, you should replace the starter relay. 

If none of these are at fault, the starter itself may have gone bad.  Most auto parts retailers will test the starter, but you will have to remove it first.  If you are mechanically inclined, you may opt to jump the battery voltage directly to the starter to determine if it will spin. 

Another issue you may be dealing with is damaged or broken teeth on the flywheel or a bad starter drive.  To check on this one, you will have to have the starter out of the car.  Inspect the drive gear for damages, as well as the flywheel teeth. 

Yet another thing you may need to check is the ignition switch.  If voltage is not reaching the solenoid or starter relay when the key is turned, look for an open P/N switch, brake switch or clutch pedal switch.  This can help in determining if the ignition switch needs to be replaced.  If you have an open P/N switch, Brake Pedal switch, or clutch pedal switch, you will need to bypass the switch with a jumper wire to check if the engine will crank.  You could also use a test light or voltmeter to determine if there is voltage passing through the switch when the key is turned on. 

If you still haven’t found your problem, check that the engine has not seized entirely.  An engine can be checked using a socket and long handle; see if the engine is able to be turned by hand.  If it cannot, your engine is locked and you have a much larger issue on your hands.  Internal engine damage or bearing failure could be to blame in this case.  If the engine has not seized, you may still suffer from engine hydrolock.  This is caused by a leaking head gasket that allows coolant to seep out.  Remove your spark plugs to check for leaked coolant.  If the engine will not crank with the spark plugs out, you may have a closer look at the possibility that the engine is hydrolocked.

While a vast number of auto problems can be to blame for a car that won’t start, this should help you in determining some of the most frequent issues auto owners face.  As an auto repair professional, I know that getting necessary repairs can be a big unexpected expense.  We hope this information will help you in finding your trouble and avoiding any unnecessary auto repair bills.