Skip the auto shop - Our mechanics make house calls

Q: engine is shaking - 2006 BMW 325i

asked by on

engine is shaking from time to time , with RPM up and down with less power for the car when its shaking. i replaced the coils and the spark plugs with no success , what should be the issue ? , i think it's an air issue...what you think ?

My car has 135000 miles.
My car has an automatic transmission.

A: Hello. This may be a sign of a failing idle...

Hello. This may be a sign of a failing idle air control valve. The idle air control valve is located on or near your intake manifold that monitors the air intake as it is mixed with fuel prior to being injected into the engine. This valve is controlled by the vehicle’s computer which will adjust idle speed based upon other measurements such as engine temperature, intake air temperature and electrical system load or voltage.

When you accelerate, the engine RPM increases, and as you let off the gas, the RPM slowly returns to the normal idling speed. However, when the engine RPM drops below the normal range of 800 RPM (for most cars), it is more than likely that you are dealing with an IAC valve problem. In cases where this valve is clogged or is failing, your vehicle will stall instead of slowing to an idle after the release of the throttle. A certified professional from YourMechanic can come to your location to diagnose the shaking issue and proceed with proper repairs.

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

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: Loud grinding noise coming from engine

Hello. If there is a loud noise like that coming from the engine accompanied by a misfire and fuel from the exhaust, then you may have a valve timing problem. It may be a failure in the timing chain. I...

Q: Why does my car vibrate so much when I am at a complete stop

There are many possible causes for this symptom; there could be a vacuum leak, or the car may simply need a tune-up. It would probably be best to have a certified mechanic take a look at the car and perform...

Q: I have a Lexus RX 350 (2008). This morning it suddenly showed the engine light indicator and started vibrating.

The burning smell and vibrations could have been caused by the engine misfiring and making the exhaust come through the intake or there is an electrical issue that is burning on the exhaust system. I recommend seeking out a professional,...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
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...
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.