This guide explores the important aspects of spark plugs for BMW models, the cost of a replacement (2025), and the complexity of the process. You'll learn which leading manufacturers' spark plugs are compatible with different BMW models, how many plugs are required for specific engines, and the cost of replacing spark plugs based on the number of cylinders. You will also find out about the most important signs of spark plug failure and the recommended replacement intervals for various BMW models.
BMW spark plug replacement cost in the UK
In 2025, replacing the spark plugs in a BMW car should cost on average between £40 and £120 depending on the number of engine cylinders. In the table below, you will find detailed information on BMW models and the cost of spark plugs, both individually and for a complete set. Please note that the prices shown do not include the cost of labour.
BMW model
Recommended brands
How many spark plugs are in my BMW model? (number of engine cylinders)
Copper, platinum, or iridium spark plugs: what to choose and when to replace them in your BMW
The ignition system plays a key role in the performance of your BMW engine. Therefore, choosing the right spark plugs will directly affect the efficiency and durability of your vehicle. When selecting spark plugs, special attention should be paid to the electrode material as this often determines their service life and performance.
Standard plugs feature an all-metal design with a copper alloy center electrode. They offer stable ignition at an affordable price, but require a replacement after 25,000 - 30,000 kilometres of mileage. This is the best option for car owners who aim for low-cost maintenance without a significant loss of performance.
There are two types of premium spark plugs: Iridium and platinum. Iridium spark plugs for BMW offer maximum durability, lasting up to 100,000 kilometres. Their special design prevents the formation of deposits, which ensures improved fuel combustion. Platinum spark plugs are mid-range products, usually lasting up to 50,000 kilometres. Due to the slow wear rate of the electrodes, they provide a good balance between cost and service life.
When selecting spark plugs, keep your priorities in mind. What is most important to you, a low price, long service life, or maximum engine efficiency?
If you find faulty, black, or defective spark plugs in your BMW, make sure to replace them with a complete set. This is advised because the characteristics of all spark plugs should be the same, preferably from the same production batch. Differences in electrode material, degree of wear or spark formation quality can lead to engine issues. A complete replacement of all the spark plugs helps maintain stable engine performance and prevents problems associated with irregular cylinder ignition.
How much does it cost to change the spark plugs on my BMW during a service?
In 2025, the average price of replacing BMW spark plugs at a garage should be between £50 and £200 - that's how much the mechanic is paid for their work. This price does not include the cost of the spare parts themselves. Labour costs will obviously vary depending on factors such as the location and type of garage. You can find a cost estimation in the table below.
Signs that your BMW spark plugs need to be changed soon
Starting problems: Difficulty starting the vehicle, especially at low temperatures, due to increased stress on the engine from worn spark plugs.
Engine performance issues:
Poor acceleration – jerking or stalling when speeding up
Rough idling – excessive engine vibrations
Ignition interruptions – erratic RPMs, misfiring, and knocking sounds
Reduced efficiency:
Increase in fuel consumption of up to 30%
Frequent refuelling
Warnings:
Illuminated Check Engine light
Strange noises – rattling or knocking sounds, especially at idle speed
Changing the spark plugs on your BMW yourself – step-by-step instructions, and how to reduce costs at a garage
You can replace the spark plug yourself if there are signs of spark plug failure or various defects. Let's take a look at this brief guide.
Using the BMW 5 Series (E39) as an example, you can look at typical difficulties when replacing spark plugs. This vehicle requires special attention and care.
Preparing for the replacement. Before you start, you’ll need the following equipment:
10 mm socket spanner
High-temperature spark plug grease
Torque wrench
Dielectric gloves
Main difficulties:
Limited space in the engine compartment
Difficulty accessing the rear plugs
Risk of damage to high-voltage cables
General procedure:
Allow the motor to cool down completely
Remove the plastic engine cover
Disconnect the battery
Carefully remove the high-voltage cables
Blow out the connector shafts with compressed air
Unscrew the spark plugs using the appropriate spanner by turning them counterclockwise. If they feel stuck, you can try to apply a penetrating oil to loosen them
When installing the spark plugs, check the spacing of the new plugs according to the manufacturer's specifications and adjust if necessary. Then carefully screw in the plugs by hand and tighten them with a torque wrench to the tightening torque recommended in the instructions
Install the ignition coils, connect the spark plugs, and reattach the engine cover
In this AUTODOC video tutorial, you will find a detailed demonstration of the entire process of replacing spark plugs for a BMW. It takes you step by step through the disassembly process, shows the necessary tools, and explains the important technical details of the installation. This video will help you to get the job done professionally!
A useful video on this topic:
How to change spark plug on BMW 520i (E39) [TUTORIAL AUTODOC]
25 March 2025 (updated) 
