Skip the auto shop - Our mechanics make house calls

Q: Car runs rough until warm, and then runs fine.

asked by on

The car runs roughly upon startup. Once the engine warms up, the car idles normally.

I would have a technician inspect your rough idle. He will probably also check for codes on the computer. It may be the air temperature sensor malfunctioning if it idles rough only when it’s cold. You may be able to remove it and clean it or replace it. If that doesn’t fix it, it may need to be checked out by a technician.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!
  1. Home
  2. Questions
  3. Car runs rough until warm, and then runs fine.

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: How do I turn quiet start on or off?

When your car is started via the remote start button, the horn will honk to confirm that the vehicle has been started. When the quiet start feature is turned on, the horn will not honk, and the climate control fan...

Q: Idles and stalls again.

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...

Q: Rough running transmission

I hope you have not yet had the transmission replaced on your Fusion. Many of the problems you have described could be transmission related, but they could very well be symptoms of other components malfunctioning. If you have not yet...

Related articles

P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...