Q: I have a 2006 BMW 525i rough idle

asked by on

I started my car up this morning and it started vibrating really hard. When it idles it goes really rough and my rpm is fluttering up and down.

My car has 70000 miles.
My car has an automatic transmission.

What you are describing sounds like a dirty or failing idle air control valve. The idle air control valve monitors the air intake as it is mixed with fuel prior to being injected into the engine at low speeds and at idle. This valve is controlled by the vehicle’s computer and will adjust idle speed based upon other measurements such as engine temperature, intake air temperature and electrical system load or voltage. This is also an important function when starting the motor as it allows the motor to run and idle on it’s own once the motor fires. When you accelerate, the engine RPM increases, and as you let off the gas, the RPM slowly returns to the normal idling speed with the help of the idle air control valve making the transition from a higher RPM back down to idle speed while adjusting the air/fuel ratio constantly to allow this to happen smoothly. When the engine RPM drops below the normal range of about 750-800 RPM, this often times will cause the engine to stall indicating a dirty or faulty idle air control valve. I would recommend having an expert from YourMechanic come to your location to diagnose and inspect your vehicle.

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. I have a 2006 BMW 525i rough idle

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 much does it cost for a tune-up on a 2006 BMW 330i?

Billing question sent to CS for the cost to perform a tune - up on a 2006 BMW 330i.

Q: Changed catalytic converter, no lights on dashboard, but codes for catalytic converter & O2 sensor still remain

Hello. If you have changed these parts and if the check engine light is not on but the codes remain then you should drive the vehicle for a while. it can take about 500 miles for them to clear. If...

Q: How much to replace 2011 bmw e90 eccentric shaft sensor?

Hi Shawn. Thanks for contacting us tonight. I've forwarded your question to our sales and service department to determine whether we have a mobile mechanic in your area that is able to complete this service for you. If we can...

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...
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...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.