Rough idle and car dies

My car is having a rough idle at about 500 rpm and will even die at light. It turns back over but not easily. Serpentine belt does squeal from 1st to 2nd gear shift. Steering becomes hard if making u-turn or tight turn.

My car has 170000 miles.
My car has an automatic transmission.

Experienced mechanics share their insights in answering this question :
Hey there. This is a common sign of a dirty or failing idle air control valve. The idle air control valve monitors the air intake as it is mixed with fuel prior to being injected into the engine. This valve is controlled by the vehicle’s computer which will adjust idle speed based upon other measurements such as engine temperature, intake air temperature, and electrical system load or voltage. When you accelerate, the engine RPM increases, and as you let off the gas, the RPM slowly returns to the normal idling speed. However, when the engine RPM drops below the normal range of 750-800 RPM (for most cars), this may indicate a dirty or faulty idle air control valve. I would recommend having an expert from YourMechanic come to your location to diagnose and repair your idle air control valve as needed.

How to Identify and Fix Common car Problems ?

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Any unusual shaking or vibrating forces coming from the engine is cause for concern. It could be something as simple as old spark plugs producing an uneven power delivery, it could be something serious like worn or broken engine mounts, or it could be even more serious in the case of internal engine damage.
If the torque converter is broken, or if there is a low fluid level in the transmission, the converter will not do its job, and the car will be unable to maintain power at low speeds, which causes the engine to shut off. A defective TCS or torque converter solenoid can also cause this issue.
One of the main reasons why your vehicle could be vibrating at idle could be due to worn out spark plugs. When a vehicle`s spark plug is faulty, it can interfere with the air-fuel ratio leading to improperly firing cylinders, resulting in a misfire while idling. Replacing your spark plugs will solve this problem.
Dirty or Worn-Out Spark Plugs

Often, your car shakes when idle simply because it`s time to replace your spark plugs! When yours are dirty or worn out, they fail to fire in the right way. If this happens, they`re unable to ignite the fuel located within each of the piston cylinders on time.

If the vehicle randomly shuts off while driving or stationary, there is usually an issue with the engine. Typical patterns here are issues with the ignition system, mixture preparation or fuel. A known error here is that the vehicle was refueled with the wrong type of fuel.
Cars shouldn`t shut off while driving, but when they do, the most common culprits are: A bad crankshaft position sensor. Other sensor issues in the engine. A faulty fuel system.
How to fix it? Cleaning or replacing the fuel filter and adding a fuel injector cleaning treatment to the fuel tank should take care of clogged fuel injectors. If the rough idle persists, it`s time to take your car to an auto repair shop.
Spark Plugs

The spark plugs are an important part of your engine`s combustion. They ignite the air and gas mixture in the combustion chamber to fire up the engine and keep it running. Dirty, old, worn, or misplaced spark plugs can cause your engine to misfire – sputter – and even stall if the plugs are really bad.

Engine vibration can be a result of many different issues in your vehicle, but when it occurs at a low RPM it usually is the result of faulty spark plugs, poor fuel pressure, or even an engine misfire.
Fuses – If the car dies while idling but restarts, there`s a possibility that there might be an issue with the fuses of the car. It`s conceivable that one of the fuses has blown. Take each fuse from the box and hold it up to the light.
Malfunctioning spark plugs can make an engine stop for a while and resume its normal functioning. It can happen when you are driving. The engine can also sound rough when idle. The misfires affect the proper functioning of your car`s engine due to failing spark plugs that have no power to ignite the fuel-air mixture.
Stop/Start Technology automatically stops and starts the vehicle`s engine under certain conditions. By turning off the engine when not needed, Stop/Start Technology can help improve fuel efficiency, thereby reducing greenhouse gas emissions (compared to the same vehicle with Stop/Start Technology not in use).
A worn out or faulty spark plug is a leading cause why your car engine vibrates or shakes uncontrollably. A worn out spark plug can prevent the fuel-air mixture to not get properly ignited in the cylinders, thus leading to misfiring.
Any unusual shaking or vibrating forces coming from the engine is cause for concern. It could be something as simple as old spark plugs producing an uneven power delivery, it could be something serious like worn or broken engine mounts, or it could be even more serious in the case of internal engine damage.
Hello, Generally, shaking during acceleration relates to an issue of low transmission fluid or transmission fluid that needs to be changed. Every time a gear change is required, the car`s computer activates a transmission solenoid, which directs transmission fluid into the valve body to engage the correct gear.
Hello, Generally, shaking during acceleration relates to an issue of low transmission fluid or transmission fluid that needs to be changed. Every time a gear change is required, the car`s computer activates a transmission solenoid, which directs transmission fluid into the valve body to engage the correct gear.
Engine vibration can be a result of many different issues in your vehicle, but when it occurs at a low RPM it usually is the result of faulty spark plugs, poor fuel pressure, or even an engine misfire.
Hello, Generally, shaking during acceleration relates to an issue of low transmission fluid or transmission fluid that needs to be changed. Every time a gear change is required, the car`s computer activates a transmission solenoid, which directs transmission fluid into the valve body to engage the correct gear.
Shaking or vibration may be caused by many different things such as faulty spark plugs, poor fuel pressure or misfires. Other things such as a faulty idle air control valve may cause the engine idle to drop below the normal idling RPM which may also cause the motor to shake or vibrate more than normal.
So, what causes car shakes when parked? Worn-out or misaligned motor mounts, worn or misaligned belts, and issues with fuel intake are common causes. Also, faulty spark plugs, ignition coils, spark plug wiring, and an oxygen sensor can cause car shakes when parked.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

My car has a rough idle when I start my car, when I stop at a light my car turns off. Is it the purge sensor?
ANSWER : This may be a result of a dirty or failing idle air control valve. The idle air control valve reads the air intake as it is mixed with fuel prior to being injected into the engine at low speeds and at idle. Since this valve is controlled by the vehicle’s computer, it will adjust idle speed based upon other measurements such as engine temperature, intake air temperature and electrical system load or voltage. When you accelerate, the engine RPM increases, and as you let off the gas, the RPM slowly returns to the normal idling speed with the help of the idle air control valve making the transition from a higher RPM back down to idle speed. When the engine RPM drops below the normal range of about ~800 RPM, this often times will cause the engine to stall indicating a dirty or faulty idle air control valve. I would recommend having an expert from YourMechanic come to your location to diagnose and repair your idle air control valve.

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My car is idling very rough.
ANSWER : The idle air control valve is common for causing a rough idle in many cars, but it sounds like you have already corrected that. Another thing you may also want to check is the crankshaft position sensor. A crankshaft position sensor monitors the position or rotational speed of the crankshaft. This information is used by engine management systems to control the fuel injection or the ignition system timing and other engine parameters. When this is faulty or not working properly, this will cause problems with the ignition system and generating spark transmission to the spark plugs resulting in starting problems, rough idling and other performance issues. You may also want to check the fuel pressure as low fuel pressure can also cause rough or poor idling if the fuel pattern being sprayed from the injectors is not consistent. This can also happen in the case of having dirty fuel injectors which may also interrupt the spray pattern of the injectors. I would recommend having an expert from YourMechanic come to your location to diagnose and inspect your car.

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My car is idling rough and flooding out when first starting. What could be causing this?
ANSWER : This may be related to a dirty or failing idle air control valve. The idle air control valve reads the air intake as it is mixed with fuel prior to being injected into the engine at low speeds and at idle. This valve is controlled by the vehicle’s computer which will adjust idle speed based upon other measurements, such as engine temperature, intake air temperature, and electrical system load or voltage.

When you accelerate, the engine RPM increases, and, as you let off the gas, the RPM slowly returns to the normal idling speed. This is all controlled by the idle air control valve. When the engine RPM drops below the normal range of 750-800 RPM, this may indicate a dirty or faulty idle air control valve.

I would recommend having an expert, such as one from YourMechanic, come to your location to determine why the car is running rough and replace your idle air control valve if needed.

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Enourmous amount of gas in exhaust and extremely rough idle and car immediately dies after starting.
ANSWER : Hi there, thanks for writing in about your 1998 Nissan Maxima. You should not try and run your car until it is fixed, or a fire may result. Check to see if the fuel pressure regulator is leaking fuel into the intake vacuum line on top of it by disconnecting vacuum line and see if fuel is in it. Replace the regulator if it is and change out the oil and filter after cranking over the engine to get excess fuel out of the cylinders. If you want to have these issues verified, a certified technician from YourMechanic, can come to your home or office to diagnose the rough idling and stalling issues.

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My car started idleing rough, vibrations soon as start car, vibrations soon as I accelerate, vibrations, rough idle bad
ANSWER : This sound like you may be having an engine misfire. Have the system checked and scanned to see if codes are present for an engine misfire. If it is, then a mechanic can check to see if a coil or spark plug has failed. You may have oil leaks in the valve cover seals that has caused the ignition to short out in the spark plug holes. A repair of your valve cover gaskets may be necessary, along with the other components that I’ve mentioned. I’d recommend having the vehicle looked at by a qualified technician who will be able to diagnose these misfiring symptoms and fix it accordingly.

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The car idles rough and is shooting out codes p0017, p0016.
ANSWER : Hello. This is a common problem with the variable valve timing solenoid on this engine. I have changed quite a few of these due to failure. I always start by checking the codes and testing the solenoids and the connectors as some of the time the connectors fail and have poor connections. There have been a few times that I have seen these codes due to low oil or the wrong oil and from the camshaft actuators failing, but most of the time it is due to the solenoids. If you are planning on having this fixed, consider YourMechanic, as a certified mechanic can come to your home or office to diagnose and repair the rough idling issue for you.

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Got my rear main seal fixed, but my car keeps having a rough idle, cutting off & the Electronic Throttle Control Light is on.
ANSWER : It sounds like you may have a faulty electronic throttle control unit. The electronic throttle unit opens and closes the throttle blade based upon input from various engine control sensors, including the accelerator pedal. This unit also controls, among other things, the cruise control function as well. When this control unit fails, this may cause intermittent stalling issues and rough idle problems. This is usually repaired by removing and replacing the throtte control unit. I would suggest having an expert from YourMechanic come to your location to diagnose and inspect your vehicle at your earliest convenience.

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My car had a rough idle, and if I sit at a red light or let the car run in idle for a few minutes my check engine light starts to
ANSWER : A dead misfire on a single cylinder may be deeper than just a spark plug. If the compression for that cylinder is very low, the cylinder cannot fire. Low compression would be caused by worn piston rings. Also, if the fuel injector is leaking or not flowing enough fuel, this may cause a misfire as well if the injector is leaking bad enough. A fouled spark plug usually leads to a coil that is not functioning or lack of compression in that cylinder. If you would like to have this taken care of, a qualified professional from YourMechanic can come to your car’s location to diagnose the rough idle and help you move forward with repairs.

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