Car trouble · Engine & check-engine light

My car hesitates when I accelerate

You press the gas and the car stumbles, lags or bogs down before it picks up speed.

Get to it this week

A starting point, not a diagnosis. Most parts stores read check-engine codes and test batteries for free.

Likely causes — tick the parts you want

  1. Worn spark plugs or a weak ignition coil

    most likely · Doable with tools and a free afternoon

    How to check: If the stumble is worst under hard acceleration or going uphill, ignition is a common cause. Have the code read if the check-engine light is on.

  2. A dirty mass airflow sensor

    possible · Most people can do this

    How to check: Look at the engine air filter. If it is very dirty or was left loose, dirt may have coated the airflow sensor in the intake tube right after it.

  3. A weak fuel pump or clogged fuel filter

    less likely · A mechanic’s job

    How to check: If the hesitation gets worse on hills, at highway speed, or when the tank is low, fuel delivery may be the problem.

  4. A transmission problem

    less likely · A mechanic’s job

    How to check: If the engine revs up but the car does not speed up to match, or shifts feel late and harsh, have the transmission checked.

Your car — the counter needs this

If the counter doesn’t have a part, your shopper asks them to order it under your name and messages you the order number. When it comes in, send someone to collect it.

Not quite it?

My check engine light is flashingMy check engine light is onMy oil light is onMy engine idles rough or shakesI smell burning oilMy car is getting worse gas mileage
My car hesitates when I accelerate — likely causes and the parts · DriverRuns