Car Stalls or Idles Roughly

Car Stalls or Idles Roughly: Rough idle or stalling at stoplights usually means the engine isn't getting clean, metered air/fuel at low RPM — dirty throttle bo

Fix soon

Drive gently and get it diagnosed within days.

What it means

Rough idle or stalling at stoplights usually means the engine isn't getting clean, metered air/fuel at low RPM — dirty throttle body, vacuum leak, or a failing idle control valve.

Most likely causes, ranked

  1. Dirty throttle body

    Carbon restricting idle airflow.

  2. Vacuum leak

    Unmetered air at idle.

  3. Failing idle air control valve

    Can't hold steady idle.

  4. Worn spark plugs

    Weak spark at low RPM.

  5. Clogged fuel filter

    Fuel starvation at idle.

Typical repair cost

Typically $10–$500

Throttle body cleaning $50–$150; IAC valve typically $150–$400. Estimates vary by vehicle. Costs are estimates and vary by vehicle, location, and shop.

Get an AI diagnosis nowDescribe your symptom or enter your code — free

Common questions

Why does my car stalls or idles roughly?

Rough idle or stalling at stoplights usually means the engine isn't getting clean, metered air/fuel at low RPM — dirty throttle body, vacuum leak, or a failing idle control valve.

Is it safe to drive when my car stalls or idles roughly?

Stalling in traffic is a safety issue — you can lose power steering/brakes at the worst moment. Get it diagnosed soon; avoid heavy traffic until fixed.

How much does it cost to fix?

Typically $10–$500. Throttle body cleaning $50–$150; IAC valve typically $150–$400. Estimates vary by vehicle.

Related