Why the car doesn’t start the first time when it’s cold: a complete analysis of the reasons and solutions

Winter or just a cool morning, you get into the car, turn the key, and the engine refuses to start the first time. You have to turn the starter 2-3 times, sometimes longer, before the engine finally “catch” and start working. The situation is familiar to many car owners, but not everyone knows what exactly causes such a failure. In this article we will look at all possible reasonsreasons why a car doesn’t start well when it’s cold - from the trivial (dead battery) to the hidden (temperature sensor malfunction).

It is important to understand: a problem with a cold start is not just an inconvenience, but a signal of possible problems. If ignored for too long, it can lead to serious engine damage, increased fuel consumption or even complete failure of the ignition system at the most inopportune moment. We will not limit ourselves to general phrases, but will give specific diagnostic instructions each unit, which you can use yourself - without visiting a service station.

The article will be useful to owners as budget VAZ 2110/2114, and more modern foreign cars like Toyota Corolla or Hyundai Solaris. Many reasons are universal, but we will also point out the nuances characteristic of different types of engines (carburetor, injection, diesel). If you are ready to understand the problem thoroughly, let's get started.

1. A dead or faulty battery is the first suspect.

Let's start with the most obvious: battery It loses capacity in the cold, and even if it copes with starting in the summer, in winter its power may not be enough. Signs of a problem:

• 🔋 The starter spins sluggishly, with “effort,” rather than vigorously and confidently.
• 💡 The dashboard dims or flickers when you try to start the car.
• 🔊 The relay clicks are heard, but the starter does not work.

How to check? Take multimeter and measure the voltage at the battery terminals with the engine off:

• 🔴 12.6–12.7 V — the battery is fully charged.
• 🟡 12.0–12.5 V - partial discharge, recharging required.
• 🔴 below 12.0 V — deep discharge, you can’t drive.

If the voltage drops below 10.5 V when trying to start - battery to be replaced. Also check leakage current: turn off all consumers (radio, alarm), remove the negative terminal and connect an ammeter between the terminal and the wire. Norm - up to 50 mA. If more, look for “gluttonous” equipment or a short circuit.

⚠️ Attention: Do not try to “light” a donor car if your battery is frozen (swelling or ice is visible on it). This may lead to battery explosion!

2. Starter problems: wear or mechanical failure

If the battery is ok but the starter turns tight or with jerks, the problem may be in itself. In cold weather, the lubricant inside the starter thickens, and worn parts (for example, bendix or brushes) work even worse. Typical symptoms:

• 🔧 The starter “sticks” and makes a grinding or squealing noise.
• 🔄 After a successful launch, extraneous noise is heard (bearings).
• 🔌 When you turn the key, a single click is heard, but the starter does not turn (faulty solenoid relay).

How to diagnose? Try to push start the car (for manual transmission). If the engine starts, the problem is definitely in the starter or its power supply circuit. Also check:

1. Contacts on the solenoid relay - they may oxidize.
2. Wiring from the ignition switch to the starter (especially ground wire).
3. Condition of teeth on the flywheel and bendix - if they are worn out, the starter will “skip”.

⚠️ Attention: If the starter “sticks” when starting, do not turn it for more than 5 seconds in a row - this can burn the winding or discharge the battery!

3. Malfunctions in the ignition system: spark plugs, coils, wires

If the engine “starts” but does not start the first time or runs intermittently after starting, the ignition system is to blame. In cold weather, problems appear more pronounced due to:

• 🕯️ Oily or worn spark plugs - carbon deposits or cracks in the insulator lead to a “breakdown” of the spark.
• 🔥 Faulty ignition coils — in the cold, the resistance of the windings changes and the spark becomes weaker.
• 🔌 Damaged high voltage wires - microcracks in insulation and current leakage.

How to check?

1. Spark plugs: Unscrew them and inspect them. Normal electrode color - light brown. Black soot is a sign of a rich mixture, white soot is a sign of a poor mixture. Also check the clearance (for most injection engines - 1.0–1.3 mm).
2. Ignition coils: Swap them. If the problem “moves” to another cylinder, the coil is faulty. For accurate diagnostics, measure the resistance of the windings (for values, see the manual of your model).
3. Wires: Check them in the dark - if “sparking” is visible, the wires must be replaced.

On diesel engines they play a similar role glow plugs. If they don't work, a cold engine simply won't start. Check them out ohmmeter - resistance must be within 0.5–6.0 Ohm (depending on the model).

How to clean spark plugs at home?

To clean carbon deposits from spark plugs, you can use an ultrasonic bath (if available) or a mechanical method: carefully clean the electrodes with fine sandpaper (1000–1200 grit) or a wire brush. After cleaning, rinse the spark plugs in gasoline and dry. Do not use abrasive pastes or hard brushes - they will damage the insulator!

4. Fuel system: from filters to injectors

If the engine does not start the first time, but the starter turns vigorously and there is a spark, the problem may be fuel supply. In cold weather, the fuel mixture should be enriched, but if the system does not work correctly, its composition is disrupted. Let's look at the key nodes:

Component	Symptoms of a problem	How to check
Fuel filter	The engine starts only after a long rotation of the starter, jerking when driving.	Inspect the filter for contamination. On injection cars it is usually located under the bottom or in the engine compartment.
Gasoline pump	When you turn the key, you cannot hear the buzzing of the pump (on injection cars).	Check the pressure in the fuel rail (normal: 2.5–4.0 bar depending on model).
Injectors	The engine “troubles” after starting, increased fuel consumption.	Test them on a stand or wash them with a special liquid (for example, Wynn’s).
Coolant temperature sensor (DTOZH)	The radiator fan runs constantly or the engine overheats.	Measure the sensor resistance at different temperatures (compare with reference values).

On carburetor engines (VAZ 2106/2107) is often to blame accelerator pump - it should inject additional fuel during a cold start. If the stream is weak or absent, check its diaphragm and valves.

5. Sensors and electronics: the hidden culprits of poor starting

Modern injection engines are controlled ECU (electronic control unit), which relies on sensor readings. If at least one of them is lying, the unit will prepare the wrong fuel mixture. Main "suspects":

• 🌡️ Coolant temperature sensor (DTOZH) - if it shows incorrect data, the ECU will not enrich the mixture for a cold start.
• 🌀 Mass air flow sensor (MAF) - if it malfunctions, the engine may “choke” or not start.
• 🔧 Crankshaft position sensor (CPS) - if it malfunctions, the spark will not be supplied at the right time.
• 💨 Absolute pressure sensor (MAP sensor) - affects the composition of the mixture.

How to diagnose?

1. Connect diagnostic scanner (for example, ELM327) and check the error codes. Type errors P0115–P0119 indicate problems with DTOZH, P0100–P0104 - with DMRV.
2. Check the resistance of the sensors (for example, for DTOZh on VAZ 2110 at 20°C it must be 3.5–4.5 kOhm).
3. Inspect the sensor connectors for oxidation or broken wires.

Plays a similar role on diesel engines. fuel temperature sensor. If he is lying, the control unit will not be able to properly heat the diesel fuel in cold weather.

6. Problems with compression and mechanical parts of the engine

If all the previous systems are in order, but the engine still does not start the first time when cold, the problem may lie in mechanical condition of the engine. Low compression, worn piston rings or worn valves mean the fuel mixture does not compress properly and has difficulty igniting.

How to check compression?

1. Remove all spark plugs.
2. Paste compression gauge into the hole of the first cylinder.
3. Ask an assistant to turn the starter (at least 5-7 turns).
4. Record the readings and repeat for the remaining cylinders.

Engine type	Normal compression	Permissible difference between cylinders
Gasoline (carburetor/injector)	11–14 bar	No more 1 bar
Diesel	25–32 bar	No more 3–4 bar

If the compression is below normal, this may indicate:

• 🔧 Wear piston rings or cylinders (needs diagnostics during disassembly).
• 🔥 Burnout valves or their incorrect adjustment (on engines with manual clearance adjustment).
• 💥Damage cylinder head gaskets (check the oil for emulsion).

⚠️ Attention: If the compression in the cylinders is close to zero, do not try to start the engine - this may lead to water hammer (for example, if coolant has entered the cylinder)!

7. The influence of fuel and additives: myths and reality

Many car owners attribute poor cold starts to fuel quality. Indeed, in winter, gas stations often sell “bodyaga” with a high content of water or impurities that freeze in the fuel system. But there are other nuances:

• ⛽ Summer diesel fuel in the cold it waxes and clogs the filters. Use winter diesel fuel (with additives) or anti-gel.
• 💧 Condensation in the gas tank - water settles at the bottom and can freeze, blocking the fuel line.
• 🧪 Octane number of gasoline - if it is lower than recommended (for example, 92 instead of 95), this may impair startup.

How to fight?

• 🔹 Add to fuel drying additives (for example, Hi-Gear HG3418) once every 3–5 refills.
• 🔹 On diesel engines use antigel (for example, Liqui Moly Diesel Fliess-Fit) at temperatures below -10°C.
• 🔹 Try to refuel at proven gas stations (for example, Lukoil, Gazpromneft).

If you suspect that there is water in the tank, you can try to remove it with alcohol (ethyl or isopropyl, 200–300 ml per full tank). The alcohol mixes with water and burns along with the fuel.

FAQ: Frequently asked questions about poor cold starting

❓ Why does the car start only after several attempts, and then it works fine?

This is a typical sign temperature sensor malfunction (DTOZH) or air leak in the fuel system. The ECU incorrectly detects the engine temperature and prepares the mixture too lean for starting. After warming up, the problem disappears, as the mixture is adjusted according to other parameters.

❓ Could poor starting be related to the alarm or immobilizer?

Yes! If the immobilizer does not recognize the key or there are problems with chip, The ECU may block starting. Try starting the car with the second key. Also check fuses (especially those responsible for the immobilizer and ECU). On some cars (for example, Reno Logan) the problem is solved by flashing the immobilizer.

❓ Why doesn’t the diesel engine start when cold, although the glow plugs are working properly?

On diesel engines, in addition to glow plugs, the following are important: compression (must be no lower 25 bar), fuel pump condition (fuel pump) and quality of diesel fuel. If compression is low, the fuel does not heat up to the desired temperature when compressed. Also check fuel shut-off valve on the injection pump - it can jam in the cold.

❓ How does oil affect a cold start?

Oil that is too thick (e.g. 15W-40 instead of 5W-30) in cold weather makes it difficult to crank the crankshaft with the starter. Use oil with the correct viscosity for your climate. Also check oil filter - if it is clogged, oil does not flow to the rubbing parts, which increases resistance during startup.

❓ Is it possible to “train” a car to start better when it’s cold?

Yes, some tips:

• 🔹 Use preheater (for example, Webasto or Defa).
• 🔹 Install high capacity battery (for example, 70–75 Ah instead of standard 60 Ah).
• 🔹Rinse before winter injectors and replace fuel filter.
• 🔹 If you have a manual transmission, squeeze the clutch when starting - this will reduce the load on the starter.