How Can You Start Your Car When It Is Warm? Here are some reasons and what to do.

It’s not uncommon to have trouble starting the car first thing in the morning, especially if the battery is dead and it’s cold outside.

What could possibly be the issue if your car has trouble starting when it is warm? After all, a warm engine shouldn’t be difficult to restart. Let’s begin with the most common causes:

A defective crankshaft, camshaft position sensor or crankshaft is the most frequent reason cars have trouble starting when it's warm. You could also have a blocked air filter or battery connector, vapor lock problem, or poor ground connection.

But, you don’t want to overlook the possibility of a bad starter or trouble with the fuel system either. 

All of the possibilities can be examined in depth, which will help you to determine why. Our article also provides some advice about what to do when the engine won’t start. 

It is difficult to start a car when it's warm

1. Defective Crankshaft or Camshaft Position Sensor

If the camshaft sensor or crankshaft position sensor fail, symptoms may be more obvious when the engine is hot. These sensors monitor the position of the rotating part and send the data to the ECU.

This information is used by the ECU to control the ignition of the spark plugs. Intermittent trouble may occur when there's a fault or miscommunication. This is especially true when the engine heats up. That’s when the internal circuitry expands, leading to more problems. However, once the engine is cool down it might start running normally again. 

Other symptoms may indicate that your position sensor has gone out of calibration. Sometimes, you may notice a flashing Check Engine Light or excessive vibrations. 

Related: 6 Signs That Your Crankshaft Position Sensor Is Not Working

2. Filter Clogged

As part of routine maintenance, the filter needs to be replaced. Many people neglect to change the air filter until it becomes blocked and full of debris. 

If the filter is maintained in a good state, the filters prevent dirt, dust, and other contaminants from entering the motor. The filter can become clogged with these particles, which will cause an obstruction. When the right amount of air can’t get into the combustion chamber, you will notice reduced engine performance resulting in decreased acceleration, misfiring and poor fuel economy.

Related: 6 Signs Your Filter is Dirty

3. Vapor Lock

You will have a vaporlock if the fuel evaporates prior to entering the combustion chamber. When the fuel begins to boil when it enters the fuel injection system, this is called a vapor lock.

The vapor is mixed with liquid, reducing the flow in the engine. This condition is more likely in hot weather. Additionally, the fuel lines are located near to the hot engine making it easier for vapor locks.

A vapor lock can cause problems with the engine starting. You may also experience stalling and a loss of power. For a quick fix to vapor locks, try placing a bag of ice in the fuel lines. 

4. Failure of Battery Connection

The battery may move in the holder as the car vibrates. The connections can become loose over time. The connection can be further reduced by corrosion.

Some cases can be more severe when the engine's temperature is high. You might have difficulty starting your engine, and you may also experience problems with electrical accessories. 

5. Bad Engine Ground Connection

Ground connections are essential to make sure the engine is running as intended. Circuit resistance can increase if the ground connection is loosening or corroded.

When this occurs, the start system and other components will also be affected. It is possible that you will notice unusual behavior in the electric components or transmission problems. A voltage drop test will be necessary to determine the cause of the problem. 

Similar: Six Signs That You Are Using Bad Ground Strap

6. Defective Starter

There is an engine inside the starter that wears down. A failing starter can result when the engine heats up. 

The starter motor contains a slip-ring commutator, carbon brushes and a carbon brush that sends current to the windings. As the parts become worn out, the motor's resistance will increase, making it more difficult to send current to the windings. 

The motor may buzz when it fails or make a clicking sound. You can determine whether the starter is failing by performing a voltage drop test. 

RELATED : 5 Signs That You're a Bad Starter

7. Questions about the fuel system

When the right amount of fuel can’t get into the combustion chamber, it can be caused by any number of fuel system issues. This could indicate a bigger problem, like a bad fuel regulator or leaky fuel injector. You also don’t want to overlook the possibility of a bad fuel pressure dampener.

These parts can appear normal, until your engine has warmed up. The fuel lines are heated and symptoms become more severe. 

What to Do When Car Won’t Start When it’s Warm

If you start to notice performance problems, it is time for you to investigate the issue. Open the hood to inspect the connections between the batteries. It is the easiest problem to fix, and it's a good idea to begin here.

You can scan your code scanner and find out why the Check Engine Light is on. Plus, if you think the fuel injectors might be clogged, it doesn’t hurt to try a fuel injection cleaner first. This is a cheaper alternative to replacing injectors. 

You have overheated your car. Now what?

If your car overheated and now doesn’t start, the problems could be more severe than what we outlined. The engine block and the cylinder heads warp when the motor heats up. This can lead to possible valve and compression damage and possibly a lack of compression.

Coolant levels can drop or leak, which is usually what causes overheating. Overheating can occur if coolant levels are low or leak, when the radiator is blocked, and if there's a problem with the water pump. Temperatures can rise due to a faulty thermostat or defective drive belt. 

It is essential to repair the damage done by the engine when it overheated. Also, fix the root cause of the issue. The extent of the damage may make this a more expensive repair.