Q: My car idles kinda rough, and it stalls when I come to complete stop and stalls when I let it run.

asked by on

What i want to know is what could cause this problem.? My car idles rough and stalls when i let it run, or stalls when i come to a complete stop. Could this be an alternator issue? Or a throttle position sensor issue? I tried looking it up but can't come across anything. Or could it be injectors? Please I want to get it fixed but don't know what the issue is. Any advice would be awesome thanks.

My car has 240000 miles.
My car has an automatic transmission.

Failures in the charging circuit (alternator, etc.) do not typically cause a rough idle. A faulty throttle position sensor and/or clogged fuel injectors can cause the engine to run roughly but those are just two among many, many potential causes of a rough running engine. What will help you is a rough idle diagnostic during which the individual cylinder firing patterns can be evaluated on a scope. Those firing patterns will allow the mechanic to see if perhaps there is "a" or a couple bad cylinders and also whether the engine is experiencing a fuel system versus ignition system problem and in which cylinders. On an engine with so many miles, 240,000 in your case, compression should be tested in each cylinder as wear in the engine could potentially cause enough imbalance, from cylinder to cylinder, to cause the engine to run roughly. You have to keep in mind that typically there will be multiple issues with an old engine, for example you could have dirty fuel injectors, a sticky EGR valve and fouled plugs due to the inevitable leakage from old valve stem oil seals, or any of a number of other combinations. The best thing to do, to see if you can get additional service life out of the engine, and you likely can, is to methodically and carefully go through the list of possibilities. YourMechanic certified technicians specialize in just that so if you set up a diagnostic, a technician will get to the bottom of this for you and give you repair options so that the engine can be restored to reasonable operating condition.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. My car idles kinda rough, and it stalls when I come to complete stop and stalls when I let it run.

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

Get a quote

What others are asking

Q: I need to know how to remove the, axle nut/hub on drivers side? After the tip of screwdriver broke off trying to take it off.

I am not sure where you broke off the screwdriver but the nut is tightened over 200 ft lbs of torque and you may need to use an impact tool to get it off. If you need assistance then have...

Q: Why does my temperature gauge go into the red when using the heater in my 1992 Chevrolet Lumina

Hello. There area lot of things that can cause this. The first thing I would check is the thermostat. If the thermostat is not opening right then this will occur. If the thermostat is fine then it may have a...

Q: Car overheating, battery light on, and can't steer my wheel properly. 2001 Pontiac Grand Am

Hi there - your symptoms could indicate a failure of the serpentine belt - aka accessory belt - which drives the alternator, power steering and water pump. If the power steering pump seized or caused excessive drag on the belt,...

Related articles

Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.