My Car is Chugging and Losing Power

Car chugging, sputtering, losing power or stalling?

When you’re driving around town or cruising on the highway, the last thing you want is for your car to start acting strangely. One of the most common signs of trouble that can be difficult to detect is when your car starts to chug and lose power. The ultimate result of this symptom is a breakdown that leaves you stranded at the side of the road, or stuck in the middle of traffic.

There are a lot of things that can cause your car to chug and lose power.image - large auto parts and tools with shiny red car.

Dirty, old, worn out, clogged filters are a common cause of car sputtering and losing power.

Air Filter

A dirty air filter, especially one that hasn’t been changed in a long time, is like a strangle hold on the engine. If clean air cannot flow into and through the engine, the engine can exhibit erratic performance such as sputtering, chugging, and stalling. Clean air to the engine is important to keep it from overheating, which affects how hard other systems have to work. The radiator and cooling system will have much more work to do if the engine is running hotter than normal because of insufficient air flow. Additionally, a filthy air filter will cause dirt and grime to build up throughout the engine, which will impact its performance and lifespan.

Fuel Filter

A dirty fuel filter blocked by dirt, crud, and even water will cause the engine to chug. Dirty fuel going into the engine creates a buildup of contaminants affect fuel efficiency, engine timing, combustion processes, and overall engine performance. Fuel is what your car needs in order to operate. The filter serves as a the gatekeeper to make sure nothing foreign or harmful is going from the fuel tank to the engine. If the filter is already dirty and worn out, you are not only risking chugging and stalling, but buildup of contaminants that could potentially cause dangerous conditions, resulting in engine seizure or even a fire.

Related: What’s Wrong With My Fuel Pump?

A clogged or failing catalytic converter can cause all kinds of problems for the engine, including sputtering and stalling.

What is a catalytic converter?

image of catalytic converter

The catalytic converter is an important part of the vehicle’s exhaust system that works to convert three harmful pollutants into harmless gases.

  1. Hydrocarbons (in the form of unburned gas)
  2. Carbon Monoxide (created by the combustion of gasoline)
  3. Nitrogen oxide (created when the engine’s heat forces nitrogen in the air to combine with oxygen)

One of the most common signs of a failing catalytic converter is a reduction in engine performance. The catalytic converter is built into the exhaust system and can affect the overall performance of the engine should it be experiencing any issues. For instance, if your converter is clogged, it will restrict exhaust flow, whereas a cracked one will leak. This can cause dangerous gases to backup and choke the engine, leading to reduction in power, acceleration, and fuel economy, as well as engine chugging, sputtering, and stalling.

Related: Signs Your Catalytic Converter is Failing

Spark plugs that are worn out, not properly installed or tuned, or just not up to spec, will cause the engine to misfire, chug, and lose power.

A regularly scheduled tune up will help you avoid common problems caused by spark plugs.

Dirty or worn out spark plugs will not fire properly, which means they’re not igniting the fuel in each of the piston cylinders in a timely manner. This causes the engine to misfire. Dirty spark plugs can sometimes be cleaned, but should just be replaced as they are generally inexpensive. A good mechanic can ensure they are installed and calibrated correctly. This will ensure your engine is “firing on all cylinders” and not chugging and underperforming.

The fuel tank breather pipe or valve is often overlooked as a cause of engine chugging and loss of power.

Fuel Tank Breather Valve

Something many people don’t consider is the fuel tank breather pipe or valve. The gas tank has to “breathe” – let air in and out as fuel levels rise and fall as the car is driven, and even as it sits idle. In order to circulate air in and out, the gas tank has a vent that relieves vacuum (suction) and pressure buildup. As you fill the tank with gas, air is pushed out or replaced by the liquid, and must go somewhere – and that’s why there is a vent or breather valve. Alternately, as you drive the fuel gets pumped out of the tank to the engine, and air replaces the liquid as it leaves the tank. If these processes do not occur without the aid of a breather valve, there can be dangerous pressures or vacuums within the tank. A strong enough vacuum can cause the fuel tank to collapse or implode on itself. Conversely, excessive buildup of internal pressure will cause the tank to blow up or explode. When the breather valve malfunctions or becomes clogged, air cannot flow properly, hence affecting fuel flow, causing the engine to chug and lose power.

Fuel injectors are oftentimes the culprit in a sputtering engine that loses power.image of two brand new fuel injectors.

Ensure your fuel injectors are clean.

Having your car thoroughly checked and tuned as part of a regular maintenance schedule will ensure that the fuel injectors in the engine are clean and fully operational. If the fuel injectors are clogged or leaking, your car will have trouble accelerating. Fuel injector problems are usually accompanied by other problems, such as ignition issues and misfiring. Keep in mind that not all cars have fuel injection – much older cars have carburetors – but injectors need to be maintained, or replaced if they become worn or overly clogged. An injector’s needle and seat effectively crash into each other millions of times over the course of a fuel injector’s life. Carbon can build up on the caps and the fuel spray pattern might be corrupted. If your car is chugging and losing power, consider a fuel injector cleaning or replacement.

Related: What You Should Know About Fuel Injectors

As mentioned earlier, there are many potential causes of your car chugging and losing power.

Here are some other things to check or consider when diagnosing your engine’s power loss and sputtering issues.
  • Failing fuel pump.
  • Timing belt or chain problems. Related: Signs it is Time to Change Your Timing Belt
  • Bad ignition coil.
  • Mass airflow sensor malfunction.
  • Oxygen sensor failure.
  • Air conditioner draining engine power.
  • Overheated cooling system.
  • Turbocharger problems.

AAMCO Colorado Can Helpimage of girl smiling, sitting in driver seat, hand on steering wheel, looking at you over shoulder out window.

At AAMCO Colorado, we run a thorough Vehicle Courtesy Check to get at the root of the problem, make an accurate diagnosis, and confirm with you the work that needs to be done to fix it right and get you back on the road. If your car is chugging, sputtering, losing power or stalling, call or schedule an appointment at your nearest local AAMCO Colorado Total Car Care center. We’re here to help!

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