Q: high idle around 3000 rpm when i start car when cold for about a minute then drops to 700 rpm, then it idles up and down in park

asked by on

when I start the car, it idles at 3000rpm for a minute then drops to 700rpm, then it will idle up and down in park or at a stop light and sometimes it stalls. it also seems to accelerate on its own while driving at any speed. I replaced the tps and iacv and cleaned the throttle body and still have the same issues. cant find any vacuum leaks. throttle body plate is not bent and cable is good.

My car has 80000 miles.
My car has an automatic transmission.

Although you replaced the idle control valve (ICV), a faulty or blown fuse in other electronically controlled systems can cause the IAC motor to malfunction, leading to a higher than normal engine idle speed. Other possible causes of a high idle include vacuum leaks, EGR system malfunctions, malfunctioning oxygen sensors, dirty fuel injectors, fuel pump malfunction, faulty spark plugs, a faulty mass airflow sensor, a malfunctioning throttle and, rarely, a PCM/ECM malfunction. With regard to vacuum leaks, on a fuel injected engine a vacuum leak will cause a high engine idle as the engine’s oxygen sensor detect the extra oxygen entering the engine through the vacuum leak. The newly lean (too much air relative to fuel) status will result in the engine’s computer pumping in additional fuel, resulting in an abnormally high idle. A malfunctioning throttle system can cause both a high idle as well as an engine stall. A dirty air intake or cracked air intake tube is often the culprit. If you desire that this high/inconsistent idle problem be diagnosed by a certified Mechanic, dispatched by YourMechanic right to your location, please request an engine idle speed diagnostic - high idle and the responding certified mechanic will get this taken care of for you. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.

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. high idle around 3000 rpm when i start car when cold for about a minute then drops to 700 rpm, then it idles up and down in park

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: Why wont the fan start? Smoking near fan, cooling fan new but wont start. engine overheats.

Hey there. As you alluded, this is a sign of a bad cooling fan relay switch. The cooling fan relay switch comes on when the temperature reaches a certain level to help cool down the radiator. When this is faulty,...

Q: Loud clunk, smoking and leaking, car shakes

Hi there, thanks for writing in about your 2001 Hyundai Elantra. This sounds serious - like the engine broke a connecting rod, which punctured the oil pan, and dumped the oil. Checking your oil level with the engine dipstick will...

Q: Q: My vehicle won't start

Hello. I would recommend first disconnecting and cleaning the battery clamps and battery with baking soda and water. Once the terminals are clean then see if it will crank over. You may need to jump start the battery if it...

Related articles

P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...
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...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.