Q: Rough idle when A/C on

asked by on

Lately I've noticed my 2004 infiniti fx45 idles rough when the a/c is running and I'm idling at a light; to the point where it feels it may shut off. When a/c is off car runs strong or when I'm driving with a/c on it runs great. It only has issues when I'm in idle. Any idea of what the issue could be?

My car has 214000 miles.
My car has an automatic transmission.

Your engine throttle body and idle air control may be clogged with carbon and engine is idling too low with A/C on causing the rough idle. Have the idle control valve and throttle cleaned out. You may also have the injection system cleaned and the combustion system cleaned to reduce carbon buildup on the back of the valves. If you want to have this looked at, a certified professional from YourMechanic can come to your car’s location to diagnose your rough idling issue and let you know what needs repair.

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. Rough idle when A/C on

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 have a code P0171 and needs repairs.

Hi there. The code P0171 is caused by the engine getting too hot and not having enough fuel to burn. Check the fuel injectors, fuel pressure, and the fuel pump to see if they are working properly. Since the vehicle...

Q: Oil leak and hissing noise

You will need to check out all of the plastic oil feed lines on the center area of the motor to see if one is broke. This will pump out the oil. Make sure not to let the oil get...

Q: Engine shakes, shuts off 1992 Volvo 740

Hey there, thanks for writing in about your 1992 Volvo 740. There are many things that can cause a shake like a worn ignition system or broken engine mounts. Being a '92, there is not an OBD-II connector, but our...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
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...