Why Won't My Car Start? Common Causes & What to Do

By On Point Mechanics, Benoni. Updated September 2026.

There is nothing more frustrating than turning your key — or pressing your start button — and nothing happens. A car that won't start can ruin your morning, make you late for work, or leave you stranded somewhere unsafe. The good news is that most no-start problems have a clear cause, and several of them you can rule out yourself in under two minutes, before you even call a mechanic.

As Benoni's RMI and MIWA approved auto repair workshop, On Point Mechanics has diagnosed and fixed hundreds of no-start problems across all makes and models. This guide gives you a quick sound test to narrow down the cause, two things you can safely try yourself, and a full breakdown of every likely cause if those don't solve it.

First — what are you hearing when you turn the key?

The sound your car makes, or doesn't make, when you try to start it is your best first clue. Find your situation below, then jump straight to that section.

What you hear	Most likely cause	Jump to
Nothing at all — complete silence	Dead battery, blown fuse or loose terminal	Cause #1
Rapid clicking (click-click-click)	Weak or dead battery	Cause #1
One single loud click	Faulty starter motor	Cause #2
Slow, heavy cranking	Weak battery, common on cold mornings	Cause #1
Grinding noise when starting	Worn starter motor gear	Cause #2
Engine cranks fine but won't fire	Fuel, spark, sensor or timing problem	Causes #4 to #8
Starts, then dies within seconds	Fuel system, sensor or alternator fault	Cause #3 or #4

The 2-minute check before you call anyone

Two quick checks rule out the simplest and cheapest fixes first.

1. The headlight test. Turn on your headlights with the engine off, then try to start the car while watching them.

• Lights dim badly or go out when you turn the key: the battery doesn't have enough charge to run the starter. Go to Cause #1.

• Lights stay bright and you hear a click or nothing: the battery is probably fine, and the fault is more likely the starter, ignition switch or a relay. Go to Cause #2.

2. Check the battery terminals. Look at the two clamps on the battery for white, blue or green crust, and wiggle each one by hand. Gauteng heat speeds up terminal corrosion, and a loose or dirty terminal can behave exactly like a dead battery. If you find corrosion, disconnect the negative (black) clamp first, then the positive, clean both with a wire brush, and reconnect the positive first. If the car starts, the battery may still need testing, since corrosion is often an early warning sign rather than a one-off issue.

If neither of those solves it, work through the causes below in order, starting with the one your sound test pointed to.

Cause #1: Dead or weak battery

The dead battery is by far the most common reason a car won't start in South Africa. Extreme summer heat and cold Gauteng winter mornings both put real strain on a battery, especially one older than three years.

Signs your battery is dead or weak:

• Rapid clicking when you turn the key

• Dim or flickering dashboard lights

• Headlights that are unusually dim

• Electrical accessories working slowly or not at all

• The car started fine yesterday but won't today

What to try yourself: jump-starting

A jump-start is the right move for a weak or flat battery. Check your owner's manual first, especially on hybrids or cars with the battery in the boot, since some have dedicated jump-start terminals under the bonnet rather than direct battery clamps.

1. Park the two cars close but not touching, both switched off, handbrakes on.

2. Connect red to the dead battery's positive (+).

3. Connect the other red clamp to the donor battery's positive (+).

4. Connect black to the donor battery's negative (−).

5. Connect the last black clamp to bare, unpainted metal on the dead car's engine or chassis, not to the dead battery itself.

6. Start the donor car, let it run a few minutes, then try starting yours.

7. Remove the clamps in reverse order.

Don't jump-start if the battery is cracked, swollen or leaking, or you smell rotten eggs. Get it towed instead.

If you have a multimeter, a healthy rested battery reads about 12.6 V, and the charging voltage with the engine running should sit around 13.5 to 14.5 V. Below about 12.4 V at rest means the battery needs charging or testing.

What to do next:

• If it starts after a jump, drive straight to On Point Mechanics. We'll load-test the battery and check your charging system, because a battery that needs jump-starting more than once needs replacing, and we'd rather catch that now than have it strand you again.

• If your battery is over three years old, plan to replace it even if it recovers.

Cause #2: Faulty starter motor

If you turn the key and hear a single loud click, or nothing at all despite a fully charged battery, the starter motor is the likely culprit. It's the electric motor that physically cranks your engine.

Signs of a faulty starter motor:

• One loud click when turning the key

• Nothing happens despite a charged battery

• Starter whirrs but the engine doesn't turn over

• Intermittent starting, sometimes works, sometimes doesn't

• Grinding noise when attempting to start

What to do: don't attempt to repair or replace a starter yourself, it needs specialist tools and often has to come out from underneath the car. Bring it to us at 50 Elston Avenue, Benoni, and we'll test and replace it quickly.

Cause #3: Alternator problems

Your alternator recharges the battery while the engine runs. A failing alternator can't keep the battery topped up, so even a fairly new battery eventually can't start the car.

Signs your alternator is failing:

• Battery warning light on the dashboard

• Car starts fine but the battery keeps going flat

• Dimming headlights while driving

• Electrical accessories behaving erratically

• A burning rubber smell from the engine bay

What to do: this is one of the most common misdiagnoses drivers make. Many replace the battery, only to find the car still won't start because the new battery drained again. We test the full charging system, battery, alternator and voltage regulator together, so you don't pay for a part you didn't need.

Cause #4: Fuel system problems

If your engine cranks normally but won't fire, the fuel system is a strong suspect. Your engine needs a precise fuel-air mixture, and if fuel isn't reaching it correctly, it simply won't start.

Common fuel system causes:

• An empty tank, more common than you'd think, especially with a faulty gauge

• A failing fuel pump that can't push fuel from tank to engine

• A clogged fuel filter restricting flow

• Dirty or blocked fuel injectors

• A failed fuel pressure regulator

What to do: check the fuel gauge first, and add fuel if it reads empty. If there's fuel in the tank and it still won't start, call us on (011) 420-0900 for a full fuel system diagnostic.

Cause #5: Ignition system faults

Your ignition system creates the spark that ignites the fuel-air mixture. If any part of it fails, the engine will crank but never start.

Components that can fail:

• Worn, fouled or incorrectly gapped spark plugs

• Ignition coils, which convert battery voltage into the high voltage plugs need

• The distributor cap and rotor on older vehicles

• The ignition module, which controls spark timing

Signs of ignition system problems:

• Engine cranks strongly but won't fire

• Misfiring or rough running before a complete failure

• A strong petrol smell when trying to start

• Poor fuel economy before the breakdown

What to do: spark plugs are a service item, usually due every 30,000 to 60,000 km depending on the vehicle. If you can't remember the last time yours were replaced, that's worth checking first.

Cause #6: Immobiliser or key problems

Modern cars have an electronic immobiliser as theft protection. If it fails to recognise your key, it will block the engine from starting even if every other system is fine.

Signs of an immobiliser problem:

• The immobiliser warning light stays on after you insert the key

• The car cranks but won't start despite a full battery and fuel

• A dead key fob battery, so the car doesn't recognise the key

• You've recently had new keys cut or programmed

What to do: try your spare key first, since that rules out a faulty individual key rather than the immobiliser itself. If neither key works, the car needs professional diagnostic scanning. We use OBD diagnostic equipment to read immobiliser fault codes and resolve the issue.

Cause #7: Faulty crankshaft position sensor

This sensor tells your engine's computer the exact position and speed of the crankshaft. Without that information, the ECU can't time fuel injection or spark delivery, and the engine won't start.

Signs of a faulty crankshaft sensor:

• Engine cranks but absolutely refuses to start

• Intermittent starting problems, works sometimes, fails other times

• Check engine light illuminated

• Engine stalls unexpectedly while driving

This fault is almost impossible to diagnose without professional equipment. Our OBD scanner can identify it within minutes.

Cause #8: Timing belt failure

If your timing belt has snapped or jumped, the engine will crank but never start, and in many cases internal damage has already happened. The timing belt keeps the crankshaft and camshaft in sync, and without that, the engine can't run.

Warning signs before failure:

• A ticking noise from the engine

• Rough running or misfiring

• Oil leaking from the front of the engine

• Being overdue on your timing belt interval, usually 60,000 to 100,000 km

What to do: if you suspect a broken timing belt, don't try to start the engine again. On an interference engine, repeated cranking can cause catastrophic damage to valves, pistons and the cylinder head. Call us immediately on 081 458 1060 for advice and towing if needed. Our full guide to timing belt vs timing chain replacement and cost explains why this failure is so expensive to ignore.

When to call a mechanic immediately

Some situations need professional help straight away rather than more troubleshooting:

• Burning smell when trying to start

• Smoke from the engine bay

• Grinding or knocking sounds when cranking

• A fuel smell inside the car

• Any warning lights on the dashboard

• The car stalls immediately after starting

Don't keep cranking the engine repeatedly. It can damage your starter motor, flatten your battery, and in fuel-related faults, flood the engine with raw petrol.

How On Point Mechanics diagnoses a no-start problem

When you bring a no-start vehicle to our Benoni workshop, here's our process:

1. Visual inspection for obvious faults like loose cables, leaks or damage

2. Battery and charging system test, measuring voltage, load capacity and alternator output

3. OBD fault code scan to read everything stored in the ECU

4. Fuel pressure test to verify fuel is reaching the engine correctly

5. Ignition system test, checking spark plug condition, coil output and timing

6. Component-specific testing of sensors, relays and modules based on what the fault codes show

This systematic approach means we find the real problem the first time, which saves you from paying for parts you didn't need.

Why choose On Point Mechanics in Benoni?

• RMI and MIWA approved, an industry-certified workshop

• Latest OBD diagnostic equipment for accurate fault finding

• All makes and models, petrol and diesel

• Transparent pricing, with honest quotes before any work begins

• Towing available if your car can't be driven in

• [Verify current Google rating before republishing]-star Google rating, trusted by Benoni drivers

• Qualified, experienced mechanics, no guesswork

Find us in Benoni

📍 Address: 50 Elston Avenue, Benoni, 1501 📞 Tel: (011) 420-0900 📱 Cell: 081 458 1060 ✉️ Email: info@onpointmechanics.co.za

Opening hours:

• Monday to Friday: 7:30am to 5:00pm

• Saturday: 7:30am to 2:00pm

• Sunday: Closed

Serving Benoni, Boksburg, Brakpan, Germiston, Ekurhuleni and the wider East Rand.

FAQ

Why does my car click but not start? Rapid clicking usually means a weak battery, or loose and corroded terminals. A single click points more toward a faulty starter or relay. Use the headlight test above to tell which.

Can I jump-start any car myself? Most petrol and diesel cars, yes, following the order above. Check your owner's manual first for hybrids or cars with unusual battery placement.

Why does my car start then immediately die? Often a fuel supply issue, a sensor fault, or, if the battery light is on, an alternator that isn't recharging the battery while it runs.

How do I know if it's the battery or the alternator? If the car dies again soon after a jump-start, or won't restart the next day, suspect the alternator rather than the battery. Read our full guide on telling battery, starter and alternator faults apart.

Is it ever dangerous to keep trying to start my car? Yes, if there's a burning smell, smoke, a fuel smell, or a suspected timing belt failure. Stop and call a mechanic rather than continuing to crank the engine.

Car still won't start? We can help.

Whether it's a dead battery, faulty starter motor, fuel pump failure or an immobiliser fault, the team at On Point Mechanics in Benoni will find the problem fast and fix it right the first time. Book a free diagnostic online or call us on (011) 420-0900 today. We also offer towing if your vehicle can't be driven to our workshop.

On Point Mechanics — Car Doctors Driven by Excellence.