What do spark plugs do?
Spark plugs convert electric current from the ignition coil into a spark that ignites the fuel and air mix inside the car engine. This combustion is what powers the engine and moves the car. Spark plugs are located in the cylinder head and are connected via external leads attached to the engine.
How often should spark plugs need replacing?
Most manufacturers recommend that spark plugs should be replaced at around every 30k miles; this is only a guideline, as the quality of the component, engine performance and driving habits can affect spark plug lifespan significantly.
The law, vehicle regulations and your MOT
Old or damaged spark plugs can affect engine performance areas that cause an MOT failure, for example, in emissions testing. Poor performing spark plugs or filters that clog up can affect the gasses that are delivered from your exhaust; replacing these faulty parts can often rectify the problem.
What causes spark plugs to stop working correctly?
Spark plugs can wear out over time, at which point they should be replaced to ensure the correct combustion of fuel. There is also a chance of potential carbon build up on the electrodes; this is known as carbon fouling and will affect the correct operation of the spark plugs. Oil can build up on the spark plugs too, which can be rectified with a simple cleaning.
Spark plugs can occasionally melt due to excessive engine temperatures. This isn’t usually a spark plug fault, but that of the engine or fuel system.
Symptoms of malfunctioning spark plugs
Starting your engine is problematic
If your car struggles or fails to start, it could be down to faulty spark plugs.
Engine cut out or misfiring
If your engine cuts out after starting or during its usual operation, if it fails to run smoothly or it vibrates excessively under normal use, then your spark plugs could be due to worn out spark plugs.
The dashboard engine warning light is illuminated
Any dashboard warning light is due to a sensor detecting fault or incorrect operation of a related component. An engine warning light could relate to a faulty spark plug.
Fuel consumption is higher than normal
Faulty spark plugs can cause your engine to burn fuel in an erratic manner, affecting both vehicle performance and fuel consumption. If you notice a change in your fuel consumption, it could be a spark plug problem.
BMW AG is a German automobile and motorcycle manufacturer that was established over 100 years ago in March 1916. They also own Mini and Rolls Royce, after taking over the two British marques in 2000 and 1998 respectively.
How popular is BMW in the United Kingdom?
BMW makes luxury vehicles and is possibly most famous for its sports saloon models. In 2018, BMW had 1.9m vehicles on the roads in the UK, a number that has been steadily increasing each year for the past decade.
As one of the ‘big 3’ German marques, along with Audi and Mercedes, BMW carries a strong reputation for making high-quality stylish vehicles, and have captured a large section of the UK market.
Luxury family and business models for every driver
Probably most popular for the 3 Series and 5 Series saloon models, BMW has got every possible angle covered for the more discerning drivers.
The full range includes everything from the 1 Series city car to the full-size saloons and sports coupes of the 7 and 8 Series models.
To provide everything you’d ever need for family motoring there’s a seven-seat MPV, their range of X model SUVs, and since 2014, the introduction of their plug-in electric i models. Top it all off with their M model high-performance supercars, the Z4 convertible and the i8 Roadster—and you’ve got the full package.
BMW: High performance on and off the track
BMW has a successful history in a range of motorsports.
They have been significant performers in touring car racing and rally driving, enjoyed success in Formula One with the BMW Sauber team, and BMW cars have been regular competitors and winners at Le Mans since the race’s early years.
BMW’s reliability and reputation
BMW ranked 16th place out of 30 car brands in the What Car? Reliability Survey in 2018. BMW hasn’t always had the best reputation for reliability but to rank alongside marques such as Honda, Volkswagen and Fiat they’re holding their own alongside plenty of the other big names.
Recent BMW recalls and reliability issues
Various recalls have been made on BMW models throughout their motoring history. The following are a list of the most recent in the UK and Europe.
22/03/2019 – BMW X5 (2018)
Incorrect tightening torque of left front seat fixing bolts
22/03/2019 – BMW X5, 5 Series (2000–2003)
Potential rupture of driver front airbag inflator
04/03/2019 – BMW X1 (2018–2019)
Rear lights may be fixed with incorrect securing units
01/03/2019 – BMW X5, X6, 7 Series, 6 Series and 5 Series (2009–2011)
Auxiliary water pump’s electronics could lead to a short circuit
01/02/2019 – BMW X5 and X6 (2007–2010)
The idler pulley bolt could become loosened
21/01/2019 – BMW M3, M4 and M4 convertible (2016)
The flange of the propshaft may become detached
27/12/2018 – BMW X6 (2014–2015)
EGR module cooler could leak
27/12/2018 – BMW 4 Series (2013–2015)
Exhaust gas recirculation module cooler could leak
All recall information sourced from gov.co.uk data.