A Dacia Logan that refuses to start is often due to a loose plug behind the ignition switch, a faulty battery charge sensor or frozen moisture in the intercooler hose in cold weather. These causes are recognisable. They can be solved with simple actions. Read on and discover how you can fix these starting problems yourself.
Starting problems occur regularly with the Dacia Logan, especially with the 1.4 MPI and 1.6 MPI engines. Owners report that their car struggles to fire up particularly in the winter months. Temperatures below 5 degrees Celsius make this problem worse, with the engine cranking slowly or not responding at all.
The causes of these starting problems are often simple. A loose electrical connection, a sensor and moisture that freezes in the intake air system all cause hassle when starting. The sensor sends incorrect information. The good thing: in most cases these problems can be solved easily without major expense.
Why won’t my Dacia Logan start because of a loose plug
Behind the ignition switch of the Dacia Logan there is an electrical connection that sends the signal from your key to the starter motor. This plug can work loose due to vibrations while driving. When the connection is not optimal, the starter motor does not receive a signal to crank the engine.
This problem often shows up unpredictably. One time your car starts without any issues, the next time nothing at all happens when you turn the key. Owners describe that the dashboard sometimes lights up, but that the engine itself does not respond.
Fortunately the solution is simple. Remove the dashboard. You can now check the plug behind the ignition switch and press the connection firmly into place. Pay attention to the cable connections and check whether any corrosion is visible on the contact points. With older Logans from the 2004–2012 period this risk is higher because of poor sealing against moisture.
How do I fix cold starting problems with the Dacia Logan
Cold-start problems at low temperatures are often caused by frozen moisture in the intercooler hose. The intercooler cools the intake air before it reaches the engine. At temperatures below zero, moisture in this hose can freeze. The airflow becomes blocked.
When the engine does not get enough air, the fuel–air mixture cannot ignite properly. As a result your car refuses to start. Your car may also fire up only with great difficulty and a lot of hesitation. After several starting attempts the engine may eventually start, but it will run roughly and irregularly until the ice has melted.
You can prevent this problem by regularly checking the intercooler hose for small cracks and condensation. In winter it can help to park the car in a garage or use an engine pre-heating system. Carry out these practical steps:
- Check that the intercooler hose is properly secured and shows no leaks
- Replace old or damaged hoses before winter starts
- Drain excess moisture from the cooling system
- Warm the engine up gently instead of driving off immediately
What to do about a faulty battery charge sensor
The battery charge sensor measures how much current the battery is receiving. The sensor also measures how much current the battery is delivering. The sensor sends this information to the engine management computer. The computer then controls the alternator. A faulty sensor sends incorrect information, so the battery is not charged sufficiently.
This leads to a problem with the battery. The battery becomes weaker and weaker, even after longer journeys. At a certain point the battery no longer has enough power to turn the starter motor. You recognise this problem from a battery warning light on the dashboard. You may also notice that after a short stop the car will no longer start.
Many Dacia Logan owners report this problem after 40,000 to 50,000 kilometres. The sensor itself is often not expensive. Identifying this issue sometimes takes some detective work. An OBD scanner can read out fault codes. These codes indicate whether the charge sensor is defective.
First test the battery voltage with a multimeter. A healthy battery shows at least 12.6 volts with the engine switched off and around 14 volts when the engine is running. If the voltage stays below these values, the charge sensor or the alternator itself may be the problem. Replace the sensor if the diagnosis points to it, and then check again whether the battery is charging correctly.
Additional causes of starting problems
Besides the three common causes there are other factors. These factors can also cause starting problems with the Dacia Logan. A weak battery is often the main culprit, especially in winter. Batteries lose part of their capacity at low temperatures, which means there is not enough power available to start the engine.
Worn glow plugs also play a role with diesel versions. These plugs preheat the combustion chamber so the cold diesel engine can start more easily. When glow plugs are not doing their job properly, you will especially notice it at temperatures below 5 degrees Celsius.
Fuel problems are also common. A dirty fuel filter causes problems. The flow of fuel to the engine is reduced. As a result the engine gets too little fuel to start. This problem gradually gets worse. It first shows up as hard starting, especially after a cold night.
The TDC sensor is another weak spot. This sensor is also called the crankshaft position sensor. This sensor sends information about when the pistons are in the correct position for ignition. If it fails, an engine warning light usually appears and the engine refuses to start. A diagnostic computer can quickly show whether this sensor is defective.
‘ Acting early saves you time, money and frustration. ’
Preventive maintenance avoids starting misery
Regular maintenance prevents starting problems. That way you keep your car reliable. Have the battery tested every year, especially before winter. Replace the battery preventively after 4 to 5 years. Do this even if the battery still seems to work. A weak battery causes most winter starting problems.
Replace fuel filters annually. You can also follow the manufacturer’s service schedule. This is extra important when you regularly fill up at cheap petrol stations, where the fuel quality is sometimes lower. A clean filter ensures optimum fuel supply.
Check electrical connections regularly for corrosion and loose contacts. This applies especially to older Logans, which are more sensitive to moisture problems. A little contact spray ensures reliable electrical connections. It can work wonders.
Pay attention to the signals your car gives you. These can be signs of developing problems. Rough idling, hesitation when accelerating or an engine warning light are indications that something is not right. Do not wait until these issues develop into a complete refusal to start. Acting early saves you time, money and frustration.
When should you go to a garage
Some starting problems you can solve yourself. Other problems require professional help. If you cannot find the cause, or if you have no experience with automotive electrics, it is wise to visit a garage. A wrong diagnosis can lead to unnecessary spending on parts that are not defective.
If you are dealing with repeated starting problems without a clear cause, professional diagnostics are now essential. Modern diagnostic equipment reads fault codes from the engine management system. The equipment often points directly to the defective component. This saves a lot of searching and prevents incorrect repairs.
If the engine does not start, make sure you do not try to crank it too often. Repeated starting attempts put extra strain on the starter motor. The battery and fuel pump are also put under extra load. This can lead to new problems on top of the existing starting issue. It is better to have the car towed to a garage than to make the situation worse.
Real-world experiences from Logan owners
Many owners report that starting problems with the Dacia Logan can be resolved well. Relatively simple actions are enough. The basic design of the car often makes repairs cheaper. Repairs are more expensive on more complex models. Parts are widely available and not expensive.
Owners of MPI engines report cold-start problems after 40,000 kilometres. This is fairly common. Replace the spark plugs or glow plugs where applicable. Also test the battery. This usually solves the problem. Forums indicate that idling is rough after starting. The engine runs irregularly after it fires up. This is normal at low temperatures and disappears as soon as the engine reaches operating temperature.
Positive experiences mainly concern the low maintenance costs. The Dacia Logan is built using proven technology. The car has no unnecessary complexity. This makes the car attractive for budget-conscious drivers. These drivers want a reliable car without high dealer costs.
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Find out more about your Dacia Logan
On the Carnews website you will find much more information about common car problems and maintenance tips. You will also find practical advice for different car brands and models. Whether you are dealing with electrical faults or engine problems, or simply want to know how to keep your car in top condition, there is always an article that will help you further. Discover more handy tips and facts about cars and become a smarter car owner.
Frequently asked questions
Common causes of starting problems with the Dacia Logan are weak or worn batteries, particularly noticeable at low temperatures, and faulty or worn spark plugs or glow plugs on the petrol and diesel versions. Contaminated or clogged fuel filters and problems with the fuel pump (loss of pressure, metal wear) also occur frequently, especially on older model years. In addition, faults in the crankshaft sensor (TDC sensor) and other engine sensors regularly lead to poor starting or a failure to start. With older Logans, corrosion and moisture problems in the electrics also play a role, which can cause intermittent starting problems.
Start with the basics: check whether the battery is in good condition (bright headlights while starting, if possible measure voltage: around 12.6 V with engine off, ±14 V with engine running) and listen to whether the starter motor turns over smoothly. If the engine turns over but does not fire up, then check whether you can hear the fuel system building pressure (the buzz of the pump when the ignition is switched on) and replace any old or clogged fuel filter. With cold-start problems (especially on diesel engines), have a garage or yourself test the glow plugs with a multimeter and replace worn ones. Finally, use an OBD reader to read fault codes (crankshaft sensor, ignition coil, pump) so you know more precisely which component is causing the starting problem.
First check whether the battery is in order: see whether the lights shine brightly and the terminals are clean and firmly attached. Try starting once with all other consumers (radio, blower, lights) switched off and listen to whether the starter motor turns normally. Look in the engine bay for loose plugs, clearly visible leaks or damaged cables. If the car still starts poorly or not at all, stop repeatedly trying to crank it and have a garage investigate further.
Yes, you can limit starting problems by carrying out regular preventive maintenance, such as timely replacement of oil, filters, timing belt and water pump. Before winter, have the battery, glow plugs and the charging and starting system tested and replace worn components immediately. Replace or clean fuel filters regularly and, preferably, use quality fuel to prevent blockages in the fuel system. If you have recurring starting problems, have an OBD diagnosis carried out to detect sensor or fuel pump faults at an early stage.
With a battery problem you usually only hear a click or very slow, weak cranking attempts, the dashboard lights and radio sometimes go off or dim strongly and the battery often has a low voltage (well below about 12 V with engine off, or no 14 V with the engine running). With a starter motor problem the lights usually remain bright, but you either hear nothing at all (no click), or only a loud click from the starter relay without the engine turning over. In addition, a worn starter motor may sometimes suddenly engage after repeated attempts, often accompanied by grinding or rattling noises. A proper battery test (measuring voltage under load) will first rule out the battery; if the problem remains while the battery is good, then the starter motor or the starter relay is the likely culprit.