The glory of a car is its ability to maintain optimal power while hitting the road. Cars are designed to run optimally when cold, warm, and hot. However, we have seen situations where cars lose power while driving. Several factors can cause poor acceleration after the car warms up.
The major reasons cars lose power when warm or hot are failing or weak fuel pump, clogged fuel filter, fuel injector issues, clogged catalytic converter, turbocharger issues, overheated cooling systems, diesel particulate filter, timing chain or belt problems, and backfiring exhaust.
In this article, I’ll explain how these issues will cause your car to lose power when warm. You’ll also learn what to do when your car starts losing power when warm and what temperature is too hot for your vehicle.
Why Does my car Lose Power When It Gets Warm?
If your car is losing power when warm, it could be due to issues like a weak fuel pump, clogged fuel filter, fuel injector issues, overheated cooling system, clogged catalytic converter, or turbocharger issues.
Clogged fuel filter
The fuel filter filters the fuel going into the engine, preventing dirt and other contaminants from clogging the fuel injectors. Over time, they become blocked from the pollutants they filter. When this happens, it won’t allow adequate fuel flow to the engine.
If you press down the accelerator and it doesn’t respond as it should, it could mean you have issues with the fuel filter. However, fuel filter issues happen when the engine is cold, warm, and hot. If the car only loses power when warm or hot, it could be one or more of the following causes.
Weak fuel pump
The fuel pump is an essential fuel system component. It exports fuel from the gas tank to the engine for optimal combustion. However, the fuel entering the engine has to be the right amount needed by the engine.
The fuel pump is always functioning as far as the engine is running. As a result, it becomes weak over time and eventually stops pumping fuel. When the gas pump starts failing, it won’t export the right amount of gas to the engine when warm or hot. This will, however, make the engine lose power since it is not receiving the necessary amount of gas for the proper combustion process.
Sometimes, a weak fuel pump can cause your car to stop when hot and won’t start until it gets cold. If you are asking, why does my car shut off when it gets hot? You have a bad fuel pump that needs replacement.
Fuel injector issues
Like the fuel pump, the engine will struggle to achieve high revs if the fuel injectors are leaking or defective. If the injector is the culprit, you’ll perceive a gas smell and have the engine misfiring.
Overheated cooling system
Car manufacturers design the cooling system to keep the engine at an average operating temperature. If you overload the cooling system at a very high ambient temperature, the components will work harder to cool the engine. As a result, the cooling system will use more engine power, reducing the engine performance.
An overheating cooling system in cold climates points to a more severe issue, and you need to track and rectify the culprit as soon as possible to prevent engine heating.
A car that loses power after driving a while in extremely high ambient temperatures is usually easy and inexpensive to fix at the early stage.
Timing chain or belt problems
Let’s get this clear; timing chain and belt problems are uncommon. But if the belt is weak, too retarded, or too advanced, it can cause the engine valves to open and close at the wrong time. As a result, the engine will lose power when warm or hot. If this is the case, you’ll hear a rattling noise from the engine.
Clogged diesel particulate filter
The diesel particulate filter (DPF) is engineered to filter exhaust pollutant particles or diesel particulate matter.
The DPF filter could get clogged over time if you own a diesel car. If this happens, the car computer could trigger the limp mode to prevent the vehicle from further damage. The limp mode will cause the car to lose power and switch off several system components. If your diesel engine loses power when hot, you likely have a clogged DPF.
Weak or failing fuel pressure regulator
The fuel regulator is an essential fuel system component that regulates the amount of fuel that enters the engine. A lousy regulator will start malfunctioning when it gets hot before it finally hits the rock. A lousy regulator will cause misfires, black exhaust smoke, and loss of engine power.
Gaps on valves
Your engine valves are essential components that also help in allowing how much air-fuel mixture goes into the engine. Small gaps in the valves will offset the air-fuel ratio needed for optimal combustion, causing rough idle, misfire, and loss of engine power.
Bad valves will cause popping noise and excessive smoke from the tailpipe when accelerating your car.
Primarily, turbochargers or turbo systems increase engine horsepower and enhance fuel economy. But if the turbo system fails, it may cause bad gas mileage and loss of engine power, especially when accelerating the vehicle.
Malfunctioning MAF sensor
The mass air flow sensor is responsible for measuring the amount of air entering the engine and forwarding the readings to the powertrain control module (PCM). If it becomes weak, it’ll start malfunctioning and cause the engine to lose power when it gets warm.
Lousy mass air flow sensors will cause issues like rough idling, bad gas mileage, hard starting, and engine hesitation.
Clogged catalytic converter
If you notice your car is losing power, it could be a symptom of a blocked catalytic converter. So, if you are wondering why does my car lose power when I accelerate, you likely have a clogged catalytic converter.
The catalytic converter converts the harmful gas emitting from the combustion chamber into less toxic gas before releasing them into the atmosphere. If the catalytic converter gets clogged, it prevents the exhaust gas from exiting the system through the tailpipe. The engine will lose power since the exhaust gas is not leaving the vehicle as it should.
Backfiring happens due to an improper air-fuel ratio in the combustion chamber. It is the loud pop or bang you hear when firing the engine. Backfiring causes loss of engine power and fire from the tailpipe, as the case may be.
Engine backfires due to several issues like weak fuel pumps, carburetor issues, and internal or external fuel leaks.
Malfunctioning ignition coils
Lastly, if you’re wondering why does my car turn off when it warms up? You likely have lousy ignition coils.
Ignition coils are prone to heat cycling or erratic functioning when they start going bad due to temperature fluctuations in the engine bay. This causes them to turn off when hot, and you can only start the car after letting it cool for 30 to 45 minutes.
What to do if my car Loses Power When it gets Warm
As you have seen, several factors can cause your car engine to lose power when it gets warm. Hence, there are several possible solutions to the problem.
Check the fuel system.
The fuel system comprises the pump, filter, injectors, regulators, and other essential components. Check these components and ensure they are all working as they should.
If you suspect the gas filter, bring it out and clean it properly and see if that will address the issue. Check the injectors for leaks and unplug the sockets to ensure they function correctly.
Check the fuel pump. The pump is likely the culprit if the car shuts down when hot and won’t start unless you let it rest for a while. Check the fuel pressure while the vehicle is hot and see if the pump can break the fuel vacuum. If it doesn’t, it has low pressure and needs to be replaced.
Inspect the ignition system.
Inspect the spark plugs and the ignition coils and replace them as needed. Pay more attention to the ignition coils because they are likely the cause.
Inspect the engine sensors.
Car sensors like the temperature coolant sensor and the mass air flow sensor can cause loss of engine power when warm. Locate and inspect them and ensure they are working correctly. While a lousy MAF sensor is likely the root cause, carefully diagnose the coolant temperature sensor and ensure it works as it should.
Check the cooling system.
Check your cooling system components and ensure they are all functioning correctly. Remember, if you’re asking why is my car overheating and losing power? The answer is a cooling system issue.
Consult a mechanic
If you have checked all these components and the car keeps losing power when the engine gets warm, consult a certified mechanic to run a proper diagnosis. After the diagnosis, the mechanic will advise you on what to do or rectify the problem.
Do cars lose power in hot weather?
If you pay attention to everything, you’ll notice your car loses power more in the summer than in the winter.
Hot weather increases ambient temperature, which affects the engine’s ability to cool down efficiently. As a result, the engine will not cool down effectively in hot weather as it does in cold weather, leading to a loss of power.
Electronic components like car sensors, ignition coils, and the powertrain control module can become overheated in hot weather conditions. And when this happens, they will not function as they should, causing reduced engine performance.
What temperature is too hot for a car?
Automakers design car engines to run between 195 to 220 degrees. Anything higher than this increases the chances of engine overheating, which could lead to catastrophic engine damage.
However, you can run your vehicle for 220 to 250 without overheating the engine as long as the engine coolant doesn’t boil.
I have provided the answer to the question, why does my car lose power when it gets warm, and explain what to do in such a situation. If the engine shuts down and refuses to start unless you allow it to cool down, you’re dealing with a lousy fuel pump that needs replacement. All you need to do is replace the pump and filter.
If the coolant gauge travels to the red zone when the car starts losing power, you have a cooling system issue that needs urgent attention.
However, if it is a regular loss of engine power, check the other components I mentioned earlier. Contact your mechanic if you don’t trust your gut or can’t rectify the problem.