Mercedes-Benz GLC Spark Plugs: Intervals, Fitment & Warning Signs
On the GLC, swapping coil packs to isolate a misfire, a technique that works reliably on most cars, has genuinely confused even experienced mechanics on related models.
Illustration for editorial purposes
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OEM Part Number: confirm via engine code — aftermarket NGK 95875 / Bosch 0 241 140 537
| Petrol engines in this generation | GLC 200 (253.942) 184 HP; GLC 200 4MATIC (253.943) 184 HP; GLC 250 4MATIC (253.946) 211 HP; GLC 300 (253.948) 211/245 HP; GLC 300 4MATIC (253.949) 241/245 HP; AMG GLC 43 4MATIC (253.964) 367/390 HP; AMG GLC 63 4MATIC+ (253.988) 476 HP; AMG GLC 63 S 4MATIC+ (253.989) 510 HP |
|---|---|
| Spark plugs (aftermarket) | NGK 95875 (iridium centre, M12x1.25, 14 mm hex, 1 kOhm suppressor); NGK 90654 (iridium, M12x1.25, 14 mm hex); NGK 97566 (iridium, M12x1.25, 14 mm hex); Bosch 0 241 140 537 (gap 0.7 mm, M12x1.25, 14 mm hex); Beru Z502 (iridium centre, platinum earth, gap 0.7 mm, M12x1.25, 14 mm hex); Champion OE269 (iridium, gap 0.7 mm, M12x1.25, 14 mm hex); Bosch 0 242 235 666 (gap 0.9 mm, M14x1.25, 16 mm hex, for the M14 AMG-type engines) |
| Genuine (OE) numbers quoted | None quoted in catalogue listings — order genuine plugs against your VIN / engine code |
| Fitment notes | The M12x1.25 / 14 mm iridium plugs (NGK, Beru, Champion, Bosch) are the family for the 2.0 turbo petrols, while the M14x1.25 / 16 mm plugs (Bosch 0 242 2xx, NGK 2477, 7811, 2288) are listed for the other engines; One brand quotes a 100,000 km replacement interval. |
Mercedes-Benz GLC Spark Plugs: A Cheap Part That Causes Expensive-Feeling Problems
A worn set of spark plugs in the Mercedes-Benz GLC doesn't make itself obvious: idle roughens slightly, acceleration loses a bit of urgency, and both symptoms are easy to blame on something else entirely. Given how inexpensive the part is, it often gets neglected for far longer than it should.
Mercedes-Benz GLC Spark Plugs: What They Do
Every combustion cycle in the Mercedes-Benz GLC's petrol engine starts with a spark plug igniting the compressed fuel-air mixture, and their condition shapes efficiency, economy and smoothness directly. Diesel versions don't need them at all, relying purely on compression to ignite fuel.
Mercedes-Benz GLC Spark Plugs: Generations & Spark Plug Count
| Diesel variants | Not applicable — diesel engines use compression ignition and have no spark plugs at all |
|---|---|
| Petrol variants (all standard trims) | 4 spark plugs — one per cylinder |
| AMG 35/45 performance trims, where fitted | Also 4 spark plugs — these use a more highly-tuned version of the same four-cylinder engine family rather than a different cylinder count |
Mercedes-Benz GLC Spark Plugs: Watch: Replacing It
Covers spark plugs and coils.
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A Genuinely Distinctive, Useful Finding Worth Knowing — Mercedes-Benz GLC Spark Plugs
If you're trying to isolate which cylinder is genuinely misfiring by swapping coil packs between cylinders, this is genuinely worth knowing: this standard diagnostic technique, which works reliably on most cars, has genuinely confused even experienced mechanics on related models, since the fault code can sometimes stay locked to the original cylinder position rather than following the coil to its new location.
It's also genuinely worth knowing a useful preventative tip: applying a small amount of dielectric grease between the top of the spark plug and the coil boot during any plug or coil replacement is a simple step worth taking.
Mercedes-Benz GLC Spark Plugs: Warning Signs, DIY Difficulty & Aftermarket Advice
These are the same regardless of make or model — see our full Spark Plugs Guide for symptoms of worn plugs, why matching your exact plug specification matters, and trusted brands to buy from.
More Mercedes-Benz Spark Plugs
The same part, covered across other Mercedes-Benz models.