You just started your car and as it idles in the driveway, the engine shakes and rumbles. Something doesn't feel right, but what's the problem? Basically, this common symptom you experience is a "hard inactivity."
A rough idle can be an indicator of several problems, and there are several ways to determine if your idle is bad. A car that has idling problems will show several symptoms, including:
- Jumps or shakes when idling
- Inconsistent/jumpy speeds
- Jumping/shaking noises
- Idle speed lower than 600 rpm
Do you suspect that your car is idling? You're probably wondering what could be causing this problem. The truth is that there are many different reasons, some more serious than others. But ultimately, if your car shudders at idle, feels bouncy, or is revving inconsistently, take your car to a mechanic for a closer look.
My car shutters when I turn it on
When your car is in park or your foot is on the brake, it idles at a constant speed. This rotational speed allows the motor to generate enough power to operate vital components without shutting down.
The idle speed should feel consistent without jumping or sliding. In most modern cars, an idle speed of 600 to 1000 rpm is average. However, if your car is idling hard, it will not feel smooth. For example, the revs will jump up and down, or they will drop below 600 rpm (or what is typical for your vehicle).
Rough idling is easy to detect when you start your car and can depend on the engine temperature when you start your car. For example, a hard idle on a cold start can be caused by different causes than a vehicle that only idles hard when the engine is warm.
In other words, pay attention to when your car vibrates while idling and to any noises. This can help your mechanic identify the problem.
Possible reasons why the car is difficult to idle
A long list of systems, components and electronics can cause harsh idle time. That makes diagnosing the cause a challenge, especially if you're not sure where to look. Therefore, it is recommended to consult an experienced mechanic if your car is idling.
Ultimately, everything from the ignition and fuel injection systems to the valves and pistons can cause hard idling. Some of the most common components are:
- Dirty/defective fuel injectors– Fuel injection systems play an important role in starting your vehicle. The system injects fuel and air into the cylinders. If the injectors are clogged or chewed, this will not provide the proper mixture of fuel and air, resulting in rough idling or slow acceleration.
What to look for:Rough, inconsistent starts, jumpy idling and lack of power when accelerating.
- Wrong idle speed– Most cars have a correct idle speed, usually between 600 and 1000 rpm.Idling carspeed may change due to wear and tear. Fortunately, an appropriate adjustment can restore the correct idle speed.
What to look for:The idle speed usually drops below 600 rpm or whatever is typical for your vehicle. The idle speed feels slower than normal.
- Defective fuel pump– The fuel pump sends gasoline from the tank to the injection system. Over time, the pump may fail due to wear or become clogged. This causes the engine not to get enough fuel.
What to look for:A bad fuel pump can cause problems with starting the vehicle, rough idling and stalling.
- Clogged fuel filter– The fuel filter filters the pollution from gasoline. Over time, it can become clogged, slowing the flow of fuel. On the other hand, the engine is not getting enough fuel.
What to look for:In addition to hard idling, random misfires, starting problems, and a car that won't start are common symptoms.
- Defective engine temperature sensor– Cars require different fuel mixtures depending on the temperature of the engine. A cold start requires e.g. a richer mixture. When the temperature sensor fails, the fuel injection system thinks the car is warmer than it is, which can lead to the wrong mixture being used.
What to look for:A bad temperature sensor will result in hard idling during a cold start. When it is warm, the problem may be less noticeable.
- Defective airflow sensor– Like the temperature sensor, the airflow sensor helps your car know how much fuel to use based on the amount of air in the engine. When this sensor fails, the vehicle's computer cannot properly calibrate the correct fuel-air mixture.
What to look for:Rough idling is one of the first symptoms to appear, followed by sputtering when accelerating or even stalling as the problem worsens.
- Vacuum leak– Your car sucks in a lot of air, and this is possible thanks to a vacuum in the intake manifold. A leak in this system will harm performance because your vehicle will not be able to regulate the proper air-fuel mixture.
What to look for:Rough idling, slow acceleration, sputtering or lack of power when accelerating are all symptoms of a vacuum system leak.
- EGR valve defective- ThatEGR valveis responsible for recirculating the exhaust gases back into the combustion system. Over time, this valve can become stuck open or closed, and performance problems, including hard idling, are the most common systems.
What to look for:In addition to rough idling, poor fuel economy, knocking noises and slow acceleration may also be present.
- Defective spark plugs– The spark plugs create the spark that ignites the fuel in the engine. Defective spark plugs therefore have difficulty igniting the fuel, causing irregular idling and difficulty starting.
What to look for:Your car may have difficulty turning and will drive fast if that is the case.
When is it time to go to a mechanic?
Hard idling can be annoying, but it shouldn't be ignored. This is often one of the first symptoms of a deeper problem. So when should you take it for diagnostics?
If the car runs fairly consistently, it's time to take it to the mechanic. If you notice other symptoms besides hard idling, you may have more serious problems. Some related symptoms to look out for include:
- Slow acceleration
- Reduced fuel consumption
- Sputtering or lack of strength
- Difficulty starting your car
- The engine stalls
In short, hard idling is often a sign that something is wrong with your car. If you have experienced this symptom more than once, in most cases it is best to have your car inspected to find the underlying problem.
Contact us for Towson car maintenance and repair
If you notice that your car is difficult to idle, it is important not to ignore the problem as it could be a sign of underlying problems. At Hollenshade's Auto Service in Towson, MD, we specialize in providing comprehensive auto repair services and are here to help you solve your idling problems.
When you notice that your car is idling hard, it is an indication that something is wrong with the engine's performance. It can be caused by several factors, such as a faulty spark plug, a clogged fuel injector, a vacuum leak, or even engine timing or compression problems. Our team of skilled technicians is experienced in diagnosing and repairing these types of problems, keeping your vehicle running smoothly and efficiently.
During your visit to our service center, our experienced technicians will perform a thorough inspection of your vehicle, focusing on the engine components and related systems. Using advanced diagnostic tools and their extensive knowledge, they can identify the cause of the idling problem. Once the problem has been located, we will provide you with a clear explanation of the necessary repairs and an estimate of the costs.
If your car is idling hard in Towson, MD, don't hesitate to contact Hollenshade's Auto Service by calling410-828-5750.Our dedicated team is ready to help you and implement it completelycar repairsyou are missing.Book an appointment todayby phone or online, and let us help you get your vehicle running smoothly again.
