You turn the key in the ignition, the starter spins vigorously, a characteristic cracking sound is heard - but the engine stubbornly refuses to start. The situation is familiar to many car owners, especially in the cold season. Crackling noise when starting the engine - this is not just an annoying sound, but a clear signal of a malfunction that cannot be ignored. In 80% of cases, the problem lies in the electrical circuit or ignition system, but sometimes mechanical failures are to blame.

In this article we will look at all possible reasons, for which the engine crackles but does not start - from a dead battery to a worn Bendix starter. You will learn how to diagnose a malfunction yourself (including without tools), which components to check first, and what to do to get the car to start again. We will pay special attention to cases when the crackling sound is accompanied by relay clicks or a complete lack of response to turning the key - these are critical symptoms that require immediate intervention.

The material will be useful to owners of both carburetor and injection cars (including VAZ 2107/2114, Toyota Corolla, Renault Logan etc.), as well as diesel engines, where a crackling noise at startup often has specific causes. If your car suffers from this problem, read on and follow the step-by-step instructions with photos and diagrams.

1. Why the engine crackles but doesn’t start: the main reasons

A cranking noise is the sound the starter makes when its gear (Bendix) cannot engage properly with the engine flywheel or when it is not receiving enough current. Let's consider 7 most common reasons this phenomenon:

  • 🔋 Low or faulty battery - the most common reason. A voltage below 11.5 V does not allow the starter to develop sufficient power.
  • 🔧 Worn or broken bendix — the starter gear does not engage with the flywheel, producing a cracking noise.
  • ⚡ Poor contact in starter circuit - oxidized terminals, broken wires or faulty relay.
  • 🛢️ Thickened engine oil - relevant for cold weather, when the starter does not have enough strength to crank the crankshaft.
  • 🔥 Solenoid relay malfunction — the starter clicks, but does not turn on.
  • 🚗 Flywheel problems — wear of the teeth or displacement of the crown.
  • 💡 ECU or immobilizer malfunction - blocks engine starting.

To more accurately determine the source of the problem, pay attention to cod character:

  • 🔊 Single loud clicks - Most likely, the solenoid relay or battery is to blame.
  • 🔊 Frequent crackling sound (like from a machine gun) - problem with bendix or flywheel.
  • 🔊 Starter crackling + hum — the starter turns, but does not engage the flywheel.

Next, we will analyze in detail each reason and how to eliminate it. Start with the simplest thing - checking the battery.

📊 How often do you have problems starting the engine?
Regularly, especially in winter
Sometimes, without a system
It used to be, now it doesn't
Never encountered

2. Battery diagnostics: first check

If the engine rattles but does not start, 90% of problems are related to the battery. Even if it “worked yesterday,” today it could be discharged due to:

  • 🔌 Headlights or radios left on.
  • ❄️ Frost (at −20°C, battery capacity drops by 30–40%).
  • 🔋 Sulfation of plates or internal closure.

How to check the battery without instruments:

  1. Turn on low beam - if it is dim or blinking, the battery is discharged.
  2. Listen to the sound of the starter:
    • 🔊 A quick "trrr-trrr" - The battery is almost dead.
    • 🔊 Slow "vzhzh" - deep discharge or malfunction.
  • Check the terminals - they should be clean and tight.

    • If there is multimeter, measure the voltage:

    Battery voltageConditionActions
    12.6–12.8 VCharge 100%Look for a problem elsewhere
    12.0–12.5 VPartial dischargeRecharge or try to “light up”
    11.5–12.0 VDeep dischargeCharge with a stationary charger
    Below 11.5 VCritical dischargeThe battery needs to be replaced

    What to do if the battery is low:

    • 🔋 Try to “light” from another car (observe the polarity!).
    • 🔌 Remove the battery and charge it with a stationary charger (current 10% of capacity).
    • 🔧 If the battery is older than 5 years, replace it.
    ⚠️ Attention: If after “lighting up” the engine starts, but a few days later the problem repeats, check generator and relay regulator. The battery may not charge while driving.

    ☑️ Battery checklist

    Done: 0 / 5

    3. Problems with the starter: bendix, solenoid relay, brushes

    If the battery is fine, but the engine still crackles and won’t start, starter is at fault. This unit consists of several parts, each of which can fail:

    • 🔧 Bendix (overrunning clutch) — the teeth or bearing wear out, causing the gear to not mesh with the flywheel.
    • ⚡ Solenoid relay — the starter clicks, but does not turn on (single loud clicks are heard).
    • 🔌 Brushes or rotor - wear leads to loss of contact and cracking.
    • 🛠️ Bearings — starter shaft play interferes with normal operation.

    How to diagnose a faulty starter:

    1. Try starting the engine bypassing the starter:
      • Put the car in neutral.
      • Turn on the ignition.
      • Push the car (or have an assistant) and engage 2nd gear.
      • If the engine starts, the problem is definitely in the starter.
    2. Check the solenoid relay:
      • When you turn the key, you should hear a clear click.
      • If there is no click, the relay is faulty.
      • If there is a click, but the starter does not turn, the problem is in the power part.
  • Remove the starter and inspect the bendix:
    • The teeth must be intact, without chips.
    • The gear should rotate freely in one direction and be locked in the other.

    Repair or replacement?

    • 🔧 If worn bendix or solenoid relay — they can be replaced separately (cost 500–1500 ₽).
    • 🔌 If you get burned windings or worn out brushes — it’s cheaper to buy a new starter (from 3000 ₽).
    ⚠️ Attention: On some vehicles (for example, VW Passat B6 or Ford Focus 2) the starter is located in an inconvenient place. If you do not have experience, entrust the repair to specialists so as not to damage neighboring components.
    How to check the starter without removing it from the car?

    Connect the positive lead of the multimeter to the starter terminal, and the negative lead to the housing. When you turn the key, the voltage should drop no lower than 9 V. If it drops to 5–7 V, the starter is faulty or there are problems in the power circuit.

    4. Problems with the flywheel: wear of the ring and teeth

    If the starter is working, but is heard when starting metallic crackling or grinding noise, the problem may lie in flywheel. This element is connected to the starter through a ring gear, which wears out over time. Typical faults:

    • 🔧 Wear of ring teeth — the starter bendix cannot engage properly, slips and makes a cracking noise.
    • 🔄 Rotating the crown - if it turns relative to the flywheel, the engagement is broken.
    • 💥 Chips or cracks - lead to uneven contact.

    How to diagnose:

    1. Remove the starter and inspect the flywheel through the hole.
    2. Check the ring teeth:
      • They should be smooth, without burrs.
      • If the teeth are “licked” or have a conical shape, the crown must be replaced.
  • Try turning the flywheel by hand (through the mounting bolt):
    • If play or uneven rotation is felt, the problem is confirmed.

    What to do:

    • 🔧 If the wear of the teeth is not critical, you can rotate the crown 180° (if the design allows).
    • 🔨 In case of severe wear, only replace the crown or flywheel assembly.

    On diesel engines (for example, Mercedes OM611 or BMW M57) the flywheel is often dual-mass. Replacing it is more expensive (from 15,000 ₽), but the problem cannot be ignored - a worn flywheel can collapse and damage the gearbox.

    💡

    If you hear a grinding noise when starting, and then the engine starts, this is a sure sign of wear on the flywheel crown. Do not delay repairs: over time, the starter will also fail.

    5. Electrical problems: wires, relays, immobilizer

    If the battery and starter are working, but the engine still crackles and won’t start, look for a problem in the electrical circuit. Most often the culprits are:

    • ⚡ Oxidized or loose contacts - at the terminals of the battery, starter or ground.
    • 🔌 Blown fuses - check the fuse box (usually F10 or F20 are responsible for the starter).
    • 📶 Faulty starter relay - may not turn on or “stick”.
    • 🔒 Immobilizer or alarm — the launch is blocked due to a failure.
    • 🖥️ ECU (electronic control unit) - if the “brains” do not give the command to launch.

    Step-by-step diagnostics:

    1. Check mass:
      • Loosen the negative terminal of the battery and clean the contact.
      • Check the ground wire coming from the battery to the body or engine.
    2. Ring the starter circuit:
      • When you turn the key, 12 V should be supplied to the starter.
      • If there is no voltage, the problem is in the relay, ignition switch or wires.
  • Check the immobilizer:
    • If the dashboard flashes key icon — the immobilizer does not recognize the chip.
    • Try starting the engine with the second key.

    Typical electrical symptoms:

    SymptomProbable CauseSolution
    The relay clicks, but the starter does not turnOpen circuit or faulty relayRing the wires, replace the relay
    Crackling noise + dim instrument lightsBad ground or discharged batteryClean contacts, charge battery
    The starter turns, but the engine does not catchECU or sensor malfunctionDiagnostics with a scanner (for example, ELM327)
    ⚠️ Attention: If after checking all components the problem remains and errors are displayed on the dashboard (for example, Check Engine) — connect the diagnostic scanner. Codes P0335 (crankshaft position sensor) or P1600 (ECU circuit break) will indicate a specific malfunction.

    6. Effect of cold and thick oil on starting

    In cold weather, even a serviceable engine may crackle and not start due to thickened oil or weak battery. At −20°C and below, the oil viscosity increases 2–3 times, and the starter does not have enough strength to turn the crankshaft.

    What to do if the car does not start in the cold:

    • 🔥 Warm up the engine — use an autonomous pre-heater (for example, Webasto) or a hairdryer (if the car is in the garage).
    • 🛢️ Fill with winter oil - for example, 0W-40 or 5W-30 (if now 10W-40 or thicker).
    • 🔋 Use a jump charger - it will give the starter additional current.
    • 🔌 Disable unnecessary consumers — headlights, stove, radio to save battery energy.

    How to avoid problems in winter:

    • 🔋 Remove the battery at night and keep it warm.
    • 🛢️ Change the oil and oil filter before winter.
    • ⚡ Check the generator - it should produce 13.8–14.4 V at idle.

    If the car has been sitting in the cold for several days and the oil is thick, do not turn the starter for more than 5-7 seconds at a time. Allow the battery to rest for 30 seconds between attempts, otherwise it may die.

    💡

    Thick oil is one of the main reasons for the “morning” crackling of the starter in winter. If the engine does not start after 3-4 attempts, do not torture the battery: heat the oil or use a “quick start” (starting aerosol).

    7. Diesel engine: diagnostic features

    If a crackling noise occurs on startup diesel engine, the reasons may be specific:

    • 🔥 Faulty glow plugs — without them, a cold diesel engine will not start.
    • ⛽ Frozen fuel — summer diesel fuel is waxed at −10°C.
    • 🛢️ Air in the fuel system — the diesel engine became airy after replacing the filter.
    • 🔧 Worn fuel injection pump (fuel pump) - does not create the required pressure.

    How to diagnose:

    1. Check the glow plugs:
      • After turning the key, you should hear the relay click (after 5–10 seconds).
      • If there is no click, check the fuse or spark plug relay.
    2. Rate the fuel:
      • If the diesel fuel is cloudy or has flakes, it contains paraffin.
      • Add antigel (eg Liqui Moly Diesel Fliess-Fit).
  • Ring the fuel shut-off valve (on the fuel injection pump):
    • If it does not receive 12 V, the problem is in the ECU or wiring.

    What to do if the diesel engine does not start:

    • 🔥 Warm up the fuel filter and pipes with a hairdryer (do not overheat!).
    • 🛢️ Bleed the fuel system (many diesel engines have a manual pump).
    • 🔋 Use trigger devices (eg. Berry Start 45).
    ⚠️ Attention: Never pour gasoline or kerosene into a diesel engine to “defrost” it! This destroys the fuel equipment. Use only specialized anti-gels.

    FAQ: Frequently asked questions about startup noise

    ❓ Why does the starter crack but not turn the engine?

    This happens when Bendix can't engage the flywheel due to tooth wear or when starter lacks power (discharged battery, bad ground). Could also be to blame solenoid relay, which does not fully extend the bendix.

    ❓ Is it possible to drive if the engine starts the second or third time?

    No! If the problem recurs, each wear-and-tear start accelerates the breakdown of the starter or flywheel. For example, a worn bendix may collapse and block the flywheel, which will lead to expensive repairs (replacing the flywheel + starter + removing the gearbox).

    ❓ How to distinguish a starter crack from a flywheel crack?

    Starter crackling - frequent, metallic, coming from the starter. Flywheel cracking - more dull, grinding, heard from the side of the checkpoint. If you listen closely, you can hear the Bendix “slipping” along the teeth of the crown.

    ❓ Why does crackling appear only when it’s cold?

    In 90% of cases it is to blame thick oil (it’s hard for the starter to turn) or dead battery (in cold weather the battery capacity drops). Also, in cold weather, problems with solenoid relay or Bendix, as the metal contracts and contacts deteriorate.

    ❓ How much does the repair cost?

    The cost depends on the reason:

    • 🔋 Battery replacement — 3000–8000 ₽.
    • 🔧 Starter repair (Bendix/retractor) - 1500–4000 ₽.
    • 🛠️ Flywheel replacement — 8,000–20,000 ₽ (including labor).
    • ⚡ Electrical diagnostics — 500–1500 ₽.

    If the problem is ECU or immobilizer, repairs can cost 5,000–15,000 rubles.