Q: Misfiring

asked by on September 30, 2016

I am driving bmw 323i E90 2006 with 196000km. When I'm starting the engine sometimes idling is so bad you find the whole car vibrating then when you put it on a drive gear it does move but not smoothly you can hear the sound even from the outside and the smell of petrol as well too sometimes when you come to a stop engine goes off or if it's on you find the Rev counting going up and down just above 1 but sometimes it can go smoothly as if nothing is wrong. So my question is what causes it to do that? And how can I solve the problem

Smell in the car Inspection $94.99 - $114.99 Get a Quote
Engine is misfiring Inspection $94.99 - $114.99 Get a Quote

This is often times related to what is called an idle air control valve which controls the air/fuel mixture at idle speed. When this is not working properly, this can cause the car to run either too rich (too much fuel - maybe causing the fuel smell) or too lean which means not enough fuel.

Either scenario can cause the car to run very rough like you have noticed. I would recommend having a certified expert, such as one from YourMechanic, take a look at the car to diagnose the misfire firsthand and help you fix it accordingly.

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


Experienced Mechanic?

Earn up to $70/hr

What others are asking

How do you activate or deactivate the Belt-Minder® system?
Your car’s Belt-Minder® system provides important alerts that increase your safety by reminding you about buckling up. However, there may be times that you need to deactivate (and then reactivate) the system. Here’s how: Make sure the ignition is off....
What does it mean if the Electronic Power Steering indicator comes on in the dash?
Your car is equipped with an electronic power steering system (EPS). This is very different from a conventional hydraulic system. If the Electronic Power Steering indicator in the dash comes on, there’s something wrong with the system. Here’s what you...
What does the engine oil pressure Warning Light mean?
The engine oil pressure Warning Light is located on your instrument panel. This light illuminates when there is an issue with oil flow through your engine. Often this problem is caused by low oil levels. Tip Like all warning lights,...
Motor making a weird noise
Hi. Unfortunately, I doubt this is a sensor problem. The transmission control module (TCM) uses input from the vehicle speed sensor (VSS) to regulate line pressure for shift timing and for torque converter clutch (TCC) application. A failed VSS can...
How much horsepower does my car have, and what is the correct tire pressure?
Hi there. According to the factory, your 2009 Jeep Wrangler with the 3.8L V-6 engine has 202 horsepower. The recommended tire pressure for your vehicle, assuming it's a Rubicon edition, would be 37 lbs of pressure on all four tires....
Oil is leaking onto the spark plugs
Oil on the spark plugs can come from a failed seal, or it can come from a failed valve cover gasket (https://www.yourmechanic.com/services/valve-cover-gasket-replacement). The spark plug well seals you are referring to can be changed. It is a slightly lengthy process...
My car will not start and the message says "theft". 2004 Pontiac Grand Prix
Hello. It sounds like you have an issue with the anti theft system malfunctioning. This commonly occurs on this vehicle. Most of the time this is caused by a failure in the key sensor in the ignition key cylinder. It...
Rear right tire wont turn
Hi There, You may have one of a couple of different issues going on here. You may possibly have a stuck brake caliper not allowing the wheel to turn or potentially a seized wheel bearing. Generally a wheel bearing will...
When I press the accelerator, there is a loud vibration coming from my engine which I can feel throughout the car.
This may be a sign of a clogged catalytic converter. The catalytic converter converts toxic exhaust gases into less harmful pollutants that are suitable to be expelled into the atmosphere. When the catalytic converter is clogged, this causes these gases...

Related articles

A Buyer’s Guide to the 2012 BMW Z4
BMW’s BMW’s entry in the hardtop roadster segment, the Z4 delivers the ideal combination of performance, looks, and standard comfort features. This two seater is not only classically stylish and heavy on extras that aren’t, well, extra, it’s also the...
How to Find Odors in a Car
Different problems can cause bad odors in a car. Inspect the inside and outside of the car, then take the necessary cleaning or repair procedures.
Top 10 Bad Car Symptoms You Should Never Ignore
Ignoring car problems costs more than fixing them right away. Never ignore if your car has rough shifting, a shaky steering wheel, or is smoking.