Q: I have a question about rough idle

asked by on December 14, 2016

I have been having some starting issues and rough idle for about two months. I've noticed when I start the vehicle I have to crank for at least 2.5 sec. It used to start right up. Now when it's idling in drive at a stop light the truck is vibrating. But the rpms are fine. I've tried replacing the battery with a new one. Same issue. Maybe my fuel injectors need cleaning? I've had a tune up just this year. The vibration isn't big but noticeable. The engine and transmission are still going strong. Maybe the throttle body is dirty?

My car has 264000 miles.
My car has an automatic transmission.

Car idle is rough Inspection $79.99 - $89.99 Get a Quote

A rough idle may be caused by many different things such as low fuel pressure, low voltage to the fuel injectors, dirty fuel injectors, a vacuum leak, a faulty Oxygen sensor or a dirty or failing idle air control valve. Any of these possibilities relate to fuel delivery issues that will disrupt the normally balanced air/fuel mixture that would otherwise allow the motor to run smoothly. I would recommend having an expert from YourMechanic cometo your location to diagnose your rough idle problem.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

What others are asking

Hard to steer.

These vehicles have hydraulic power steering systems. If any fluid is leaking from the system it can cause the system not to function properly. The basic parts of the system include the power steering pump, lines, rack and pinion, and...

Car shut off while driving

Hi There, What you are describing sounds like a weak or dead battery. The clicking noise when trying to start the car is a common indicator that the battery does not have enough power to turn the engine over. You...

Brakes and gas pedal 1979 GMC C1500

Hello - I would first check the throttle return spring at the carburetor - to make sure it's still there, and connected properly so that the throttle default position is "closed". Then check to see if the linkage back to...

Car squeaking.

Without hearing the noise it will be difficult to give you an accurate recommendation. Rubber bushings and moving suspension components can cause these type of noises. Also rubber seals where body panels come together such as doors to body can...

My vehicle won't start

Hello. I would recommend first disconnecting and cleaning the battery clamps and battery with baking soda and water. Once the terminals are clean then see if it will crank over. You may need to jump start the battery if it...

Truck won't start after warming up

You need to check the purge valve to see if it is leaking vapor into the intake when at idle and when the engine is off. If it does then it may be bad and needs to be replaced. Check...

Coolant leak

Hi! Commonly, a coolant leak on your particular vehicle will be from a thermostat, bad hose connection, or a cracked radiator. I suggest pressure testing the cooling system to help highlight the area that may be leaking. If a Check...

Car has been reving in park/idle at around 1000-3000 rpms

Code P0123 relates to the throttle position sensor. The throttle position sensor (TPS) is a sensor used to monitor the throttle position of the throttle plate inside the throttle body in relation to your foot position on the gas pedal....

Car won't start - 2012 Land Rover LR4

Hey there. Land Rover has a TSB out for a keyless module that may malfunction. Of the "Smart Key Not Found" message that will occur on the dash. This repair would require the module to be replaced and programmed at...

Related articles

How Does an Engine Idle High and Low?
A common problem that car owners experience is high or low engine idle. A damaged intake gasket, cold air intake, or PCV valve can cause idle issues.
How Does an Engine Idle High and Low?
A common problem that car owners experience is high or low engine idle. A damaged intake gasket, cold air intake, or PCV valve can cause idle issues.
How Long Does a Top Dead Center (TDC) Sensor Last?
The The top dead center (TDC) sensor is the point from which the firing order is determined and the ignition system measurements are taken. The measurements are normally defined as before top dead center and after top dead center. The...