BMW Rough Idling
Your BMW is usually very reliable. Known for sporty credentials, BMWs have been serving car lovers for decades. Each BMW is a superior driving machine with high-quality craftsmanship and driving ability.
At some point, your BMW may run into stalling issues or rough idling – which is a cause for concern for any car owner.
If you’re experiencing this issue currently, our team of BMW experts are on hand to assist you. If you need a service, inspection, diagnosis or repair, Roade Main Garage’s team are BMW specialists with decades of experience.
This blog will dive deeper into the causes and possible solutions to rough idling and stalling in BMWs.
Keep reading to find out more!
What is Rough Idling? Why is it a Concern?
A rough idling BMW vibrates and does not sound healthy. Usually, your engine will stay at a constant RPM when idle and stationary. Your dashboard will display engine RPM and normally idle speed is between 600 and 1000 rpm.
You’re experiencing a rough idling car when it:
- Drops below 600 or rises above 1000 rpm.
- There is an increase in vibration and shaking.
- If you hear loud noises such as bangs and pops when the engine stalls or backfires.
If you experience any of these symptoms, it’s best to visit a BMW specialist workshop for diagnosis. Our team at Roade Main Garage are experts in BMW cars and can fix your rough idling car in no time. If you visit us right away, we might be able to fix it on the same day. If you ignore it, it could get worse, causing expensive repairs later on.
The Most Common Reasons For Poor BMW Engine Idling
Poor idling ultimately depends on your BMW model, model year and engine and is caused by several factors. Here are the most common causes for rough idling in your BMW:
- Vacuum Leak
An increased airflow is a result of a leaking vacuum hose. Usually, vacuum hoses allow for a tight seal in the combustion chamber of the engine as it operates. This ensures the air-fuel mixture is in the correct ratio and results in a proper burn to produce power. The rubber material which makes up the hose can break down over time and leak.
Listen out for a hissing noise when your engine is on, and your vehicle is parked up. If a leaky vacuum hose is found, it could be the cause of rough idling.
- Blocked Air Filter
Your engine air filter prevents unwanted material from entering the combustion chamber and mixing with the fuel. As dirt, debris and other contaminants can cause blockages to the air filter and can block airflow.Â
The air filter is a serviceable part of your BMW and should be replaced at every interval.
- Spark Plug or Ignition Coil Damage
Spark plugs can get covered in carbon for various reasons and the more build-up, the less effective they become. A defective spark plug causes your engine to idle poorly.
Spark plugs are used to ignite the air-fuel mixture in the engine to produce power. If you notice no carbon build-up on your spark plugs, it could be your ignition coil at fault.
Reach out to our expert team if you need your spark plugs or ignition coils replaced. Our team of trained professionals have the right knowledge and tools to replace your spark plugs and identify rough idling issues.
- Problems With Fuel Injectors
A clogged or faulty fuel injector means that fuel flow will be limited, causing rough idling. As fuel injectors are so carefully engineered to deliver the precise amount of fuel, your engine will not run properly if there is any disruption to the fuel flow.
Your fuel filter could be the culprit and replacing this first may be the solution to poor idling. Also, injector cleaning products are available, they mix with the fuel and help to clean the injectors as the fuel passes through.Â
However, if these solutions don’t work, it may mean your injectors need replacing. We recommend this job is only performed by a trained professional.
- Fuel Pump Issue
Fuel pumps deliver fuel from the fuel tank, up through the filter and into the rails and injectors. If the fuel pump is not operating as it should, it may reduce the flow of fuel to the injectors and cause rough idling.
Replace the fuel pump if the issue persists, you can also use a fuel system cleaner.
- Broken O2 Sensor
Your O2 sensor helps work out how much oxygen is flowing into and out of the engine. Your BMW ECU (Engine Control Unit) changes the amount of fuel injected based on the readings from the O2 sensor.
The O2 sensors are located on the exhaust system under the car. They can be inspected upon removal and if they are visibly damaged, they need to be replaced. This task should only be performed by a BMW specialist technician.
- Throttle Position Switch (TPS) Fault
Your throttle body inside your engine bay has a throttle position switch. This switch is read by the ECU to determine the throttle position and adjusts elements like ignition timing and air-fuel mix to ensure your engine is running smoothly. A faulty TPS could cause a misalignment in the calculations and therefore rough engine idling.
With a team of BMW experts on hand to assist, Roade Main Garage can work out if the cause of your rough idling issue is your TPS and get your car back running smoothly in no time.Â
Roade Main Garage is your Local BMW Expert
There are a lot of factors that make up a smooth-running engine. To ensure proper spark, your spark plugs, and ignition coils are responsible and to ensure there is enough fuel, your fuel injectors, filter, and pump need to be fully working.
To avoid any uncertainty and potentially making the problem worse, we recommend reaching out to our team of BMW experts at Roade Main Garage.
We work out what is causing your BMW to idle poorly and can get your car running smoothly once more. Contact us today for expert BMW diagnostics, servicing, and repair.
