The car does not start and crackles when you turn the key: causes and repair methods

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A dry, fractional crackling sound from under the hood when trying to start the engine most often indicates a critical discharge battery or physical wear and tear bendix starter. When the key is turned in the ignition switch, the voltage in the on-board network drops so much that the retractor relay cannot keep the gear engaged with the flywheel, causing a characteristic knocking noise. This symptom cannot be ignored, since repeated attempts to start the engine with a faulty starting system can completely “kill” the battery or damage the flywheel teeth. Understanding the nature of sound allows you to immediately weed out non-working options and focus on checking power contacts and state of charge.

Sometimes the situation is aggravated by oxidation of the terminals or poor ground contact, which creates a high contact resistance. The current simply does not reach the starter in full, causing the same symptoms as with a dead battery. It's important to quickly diagnose the source of the problem so you don't end up stuck in a parking lot at the wrong time. Further actions depend on whether you can determine what exactly is making the sound: the starter itself or the relay under the hood.

Diagnostics of the battery and electrical contacts

The first and most likely culprit is that the car won't start, is the current source. Even if the headlights are on and the alarm is working, there may not be enough starting current. When you turn the key, the starter draws hundreds of amps, and if the battery is (old) or undercharged, the voltage drops below 9 volts. At this point, the solenoid relay is activated, but immediately switches off due to lack of energy, after which the cycle repeats, creating a ratcheting effect.

It is necessary to visually inspect the battery terminals. White or greenish coating on the contacts is an oxide that interferes with normal current exchange. Even a tightly screwed terminal may not allow current to pass through the oxide layer. It is recommended to remove the terminals, clean them with fine sandpaper or a brush until they have a metallic shine and tighten them tightly. It is also worth checking the attachment of the ground wire to the body or engine, since its rotting is a common problem in old cars.

• 🔋 Check the voltage at the battery terminals with a multimeter: the norm for starting is at least 12.5 V.
• 🔧 Clean terminals and contacts from oxides, even if they look visually clean.
• ❄️ In cold weather, the battery loses up to 40% of its capacity, so a weak charge in the summer will crack in the winter.
• 🔌 Try to “light” from another car: if the engine starts easily, the problem is definitely in the battery.

⚠️ Attention: If, when trying to start, you smell a burning smell or see sparking in the terminal area, stop trying immediately. This is a sign of a short circuit or poor connection that can cause the wires to melt.

The condition of the battery itself should be taken into account. If it is more than 4-5 years old, the lead plates inside may have deteriorated or become sulfated. In this case, even a short-term charge from another car will only give a temporary effect. Electrolyte density - another important parameter for serviceable batteries, which can be checked with a hydrometer.

Malfunctions of the starter and retractor relay

If the battery is working properly and fully charged, but when you turn the key you hear a metallic crackling or clicking sound, the problem lies in the battery itself. starter. The solenoid relay is an electromagnet that pushes the bendix gear forward to engage the flywheel. If the contacts inside the relay are burnt or the coil is unstable, the gear will constantly “jump”, hitting the flywheel but not turning it.

Often the cause is wear on the starter motor brushes. Graphite brushes wear out over time and contact with the commutator becomes intermittent. The starter motor jerks, but does not develop the required speed. Sometimes it helps to gently tap the starter housing with the handle of a hammer (if you can get to it), which can temporarily restore contact between the brushes, allowing you to start the car to get to the service center.

The Bendix (overrunning clutch) can also be the cause of the noise. If its gear is worn or stuck in the extended position, it will rattle against the flywheel. In some cases, the Bendix gear simply slips without transmitting torque, which is accompanied by a squealing or crackling sound. Replacing the Bendix requires removing the starter and partially disassembling it.

How to distinguish a relay from a starter

Remove the starter and apply 12V to it directly. If it turns briskly, there is a problem in the wiring or relay. If it cracks, the unit itself is faulty.

• ⚙️ Burnt dimes of the retractor relay do not allow full current to pass through the windings.
• 🔨 A stuck bendix does not return to its original position after starting.
• 📉 Wear of starter bushings (sleeve bearings) leads to armature skew.
• 🔌 Break or short circuit in the windings of the armature or starter stator.

It is important to note that constant starter noise can cause the teeth on the engine flywheel to chip. If you ignore the problem, replacing the starter can turn into an expensive repair involving removing the transmission and replacing the flywheel. Therefore, at the first sign of incorrect operation of the starting device, careful troubleshooting node.

Mechanical engine and transmission problems

In rare cases, a crackling sound when trying to start is not associated with the electrics, but with the mechanical wedge of the engine. If the engine does not have enough oil or overheats, the crankshaft liners could get stuck. In this case, the starter is physically unable to turn the crankshaft, and you hear a heavy, strained crackling or knocking sound. Attempts to start such an engine will lead to damage to the starter or breakage of the timing chain/belt.

It is also worth checking whether the generator or pump is jammed. If the attachment belt breaks, these units may stop, but if the belt is intact and the unit is jammed, the starter will not be able to turn the crankshaft pulley. This can be diagnosed by removing the belt and attempting to turn the pulleys manually. If any of the units does not spin, the problem has been found.

For vehicles with a manual transmission, it is important to ensure that the clutch pedal is depressed. Although usually this will simply prevent the starter from turning the engine (protection), in some older models, if the clutch is not depressed, the starter will try to turn the gearbox shafts, which will create additional load and strange sounds if there is a malfunction in the transmission.

⚠️ Attention: Never try to start an engine with signs of a wedge (water hammer, lack of oil) using the “dragging” method or using a pusher. This is guaranteed to lead to a major overhaul of the engine.

The effect of low temperatures on engine starting

In winter, the problem of “cracking and won’t start” becomes a widespread phenomenon. Low temperatures increase the viscosity of engine oil, creating enormous resistance to rotation of the crankshaft. The starter requires significantly more energy to crank the engine. If the battery is not fully charged, it simply will not be able to overcome the resistance of the frozen oil, and the solenoid relay will begin to crackle.

In addition, in diesel engines in winter, paraffin in the fuel or water in the fuel filters often freezes. Although this does not directly cause the starter to crack, the engine may seize and stall, creating an intermittent running rhythm that can be confused with a starting problem. In gasoline engines, the spark plugs may be flooded with fuel due to a rich mixture during a cold start.

To make starting in cold weather easier, experienced drivers use the “blow-through” method. You need to turn on the high beam headlights for 10-15 seconds to “warm up” the battery through a chemical reaction, then turn off the lights and try to start the engine. Preheating the oil and antifreeze with a preheater also helps.

• ❄️ Use winter types of oils with low viscosity (for example, 5W-30 or 0W-20).
• 🔥 Keep the battery warm or use a thermal case for the battery.
• ⛽ Monitor the quality of the fuel and the presence of a water separator in the filter.
• 💡 Warming up the battery by turning on the light before starting increases the current output.

Symptoms and Solutions Comparison Chart

To quickly identify the problem, it is convenient to use a pivot table. It helps to compare the nature of the sound and accompanying signs in order to make the right decision about further actions. Do not attempt electrical treatments if the problem is mechanical, and vice versa.

Symptom	Probable Cause	Actions	Difficulty
Quiet clicks, the lights go out	The battery is discharged, the terminals are oxidized	Charging, cleaning, "lighting"	Low
Loud crash, light doesn't go out	Defective solenoid relay	Replacing a relay or starter	Average
Squealing and crackling	Worn bendix or flywheel crown	Bendix/flywheel replacement	High
Single click, silence	Open circuit, blown fuse	Checking wiring and fuses	Low

Algorithm of actions in case of startup failure

If you find yourself in a situation where your car won't start, act calmly. Panic and random twisting of the key will only worsen the battery drain. First, make sure it's safe by turning on your hazard lights. Then perform initial diagnostics based on the sound and response of the instruments on the panel.

Check if the lights on the instrument panel come on when the ignition is turned on. If they light up but go out when you try to turn the starter, look for a problem in the battery or contacts. If the lights are bright, but there is a crackling noise, check the starter. If there is silence, check the fuses and ignition switch.

If self-repair is impossible, and you need to start the car urgently, you can try to close the contacts of the solenoid relay with a screwdriver (being extremely careful not to short it to the body and get an electric shock). This will allow current to be supplied directly to the starter, bypassing the ignition switch and relay. If the starter spins briskly, the problem is in the electrical control circuit.

⚠️ Attention: Closing contacts with a screwdriver is dangerous due to sparking and the possibility of damaging the car’s electronics. Use this method only in emergencies and if you have the skills.

Frequently asked questions (FAQ)

Why does the starter crackle but not turn over even though the battery is new?

Even a new battery may be discharged or have a manufacturing defect. However, if everything is fine with the battery, the reason lies in poor ground contact, burnt contacts inside the solenoid relay, or wear on the brushes of the starter itself. It is also possible that the wires going to the starter may be broken.

Is it possible to drive if the starter sometimes cracks?

You can drive, but as long as the engine is already running. However, operating a car with a faulty starter is risky. At any moment you may not start. In addition, the cracking noise indicates that the bendix is ​​not engaging correctly, which leads to the destruction of the flywheel teeth, which is very expensive to repair.

How much does it cost to replace the solenoid relay?

The cost depends on the car model. The relay itself can cost from 1000 to 5000 rubles. However, on many modern cars the relay is not sold separately from the starter, and you have to buy the assembly. Replacement work also varies depending on the availability of the starter in the engine compartment.

How to extend the life of a starter?

Do not keep the key in the "start" position for more than 10-15 seconds. If the engine does not start, allow the starter to cool for a minute. Keep the battery contacts clean and charge the battery on time. Avoid getting water and dirt on the starter housing when washing the engine.

Does fuel quality affect startup noise?

Fuel quality does not directly cause starter noise (mechanical sound). However, poor fuel can cause the engine to seize and stall, creating a rough running sound. But if you hear just a metallic clang or dry crackling without flashes in the cylinders, the problem is in the mechanics or electrics of the start, and not in gasoline.