Spark plug replacement (B58, B48, N55) cost
B58, B48, N55
Last updated
Price summary
| BMW dealer | $575–$975 What owners paid: the middle of 3 sourced prices (full spread $200–$1,000) |
|---|---|
| Independent shop | $465–$675 What owners paid: the middle of 4 sourced prices (full spread $360–$1,200) |
| All shops | $430–$975 The middle of 7 sourced prices |
What owners paid (middle half) One owner price
Before tax and shop fees. Prices vary by region, parts brand and what's included.
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What owners paid
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Submitted by owners through this site and reviewed before publishing. Shown separately from the public posts below.
From public posts 9
| Price | Shop | Vehicle / scope | Location | Year | Source |
|---|---|---|---|---|---|
| $1,000 | Dealer quote |
2018 340i (B58) Spark plugs |
CA | ~2025 | r/BMW |
| $950 | Dealer quote |
2020 M340i (B58) Spark plugs |
— | ~2025 | r/BmwTech |
| $200 | Dealer paid |
B58 Spark plugs |
— | ~2025 | r/BmwTech |
| $360 | Independent paid |
M40i (B58) |
Bay Area, CA | ~2025 | r/BMW |
| $500 | Independent quote |
B58 Spark plugs |
— | ~2025 | r/BmwTech |
| $1,200 | Independent quote |
2015 X1 (N55) Spark plugs |
— | ~2025 | r/BmwTech |
| $375 | Dealer paid |
M550i (N63) Spark plugs · not used in range: N63 V8, not an engine on this page |
— | ~2025 | r/BmwTech |
| $500 | Independent quote |
G20 3 Series (B48) Spark plugs |
— | ~2024 | G20 Bimmerpost |
| $618 | Dealer quote |
2013 328i (N20) Spark plugs · not used in range: N20, not an engine on this page |
— | ~2024 | r/F30 |
Grey rows are shown for context and left out of the range. Years are approximate (date of the post). The range is the middle half of full-job USD prices for each shop type, published once there are at least 3; labor-only, customer-supplied-parts, warranty cost-share and bundled jobs are listed but left out.
Symptoms
- Misfire codes or a flashing check engine light
- Rough idle or hesitation under load
- Spark plugs due on the service schedule
Which cars are affected
Prices found for G20 3 Series (330i, M340i), F30 340i, G01/G05 M40i and E84 X1 with the N55.
G20 3 Series 2019–present F30 3 Series 2012–2019 G01 X3 2018–2024 G05 X5 2019–present
BMW's 2026 US maintenance booklet lists spark plugs at every 6th engine oil service (about 60,000 miles) for all models, and every 3rd (about 30,000 miles) for M2, M3, M4, M5, X5 M, X6 M and XM. Four-cylinder B48 jobs use four plugs; six-cylinder B58 and N55 use six. Prices below are what owners reported being quoted or paying; BMW Value Service also publishes a spark plug price for older cars on our Value Service page.
Indie shops near you
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Related repairs
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N52, N55, B46/B48, B58 and related Valvetronic enginesB58 / B48 oil filter housing (coolant leak)
B58 and B46/B48 · indie est. $1,225–$2,101 · dealer est. $2,465–$4,010B58 valve cover / PCV failure
B58; one B46/B48 point included and labeled · indie est. $1,248–$2,352 · dealer est. $3,128–$5,052ZF 8-speed automatic transmission fluid and pan/filter service
ZF 8HP automatic behind the N55, B58 and others · indie est. $535–$789 · dealer est. $1,080–$1,515All repair prices → · Dealer vs independent prices for every job
Before you pay, check the VIN for recalls. Some failures are covered by a safety recall or a BMW warranty extension.
Spark plug part numbers and specs
| Engine | BMW part number | NGK plug | Factory gap |
|---|---|---|---|
| B58 first generation (e.g. 2016–2019 340i, 440i, M240i) | 12120040551 (also 12120041666) | 94201 (SILZKGR8B8S) | 0.75 mm / 0.030 in |
| B46/B48, B58TU, S58 (G20, G22/G23, G42, G29 Z4 and others) | 12122455258 (also 12125A4EF60) | 96206 (SILZKGR8E8S) | 0.75–0.8 mm / 0.030–0.031 in |
- Thread M12 × 1.25, 14 mm 12-point (bi-hex) socket; BMW tool 83300495560.
- Tightening torque: 23 ± 3 Nm (about 17 ft-lb).
- Plugs come pre-gapped. Tuners sometimes close the gap for high boost, which shortens plug life.
- Part numbers supersede; confirm by VIN.
Sources for this section: FCP Euro: 12120040551 kit specs · NGK 94201 specs · BimmerWorld: 12122455258 / NGK 96206 · Navardi: B58 plug guide · Socket tool 83300495560 note
DIY or shop?
On B48 and B58 engines the plugs sit under the ignition coils at the top of the engine, so the job is coil covers off, coils out, plugs out. You need the 14 mm 12-point thin-wall socket and a torque wrench. One independent shop invoice above shows 1.7 hours of labor for a six-cylinder. Misfires that come back after new plugs often point to a coil: ignition coil cost.
Common questions
How often should BMW spark plugs be changed?
BMW's 2026 US maintenance booklet lists every 6th oil service (about 60,000 miles) for most models, and every 3rd (about 30,000 miles) for M2, M3, M4, M5, X5 M, X6 M and XM.
What is the spark plug torque on a B58?
23 ± 3 Nm, about 17 ft-lb, for the M12 × 1.25 plug.
Do I need to gap new B58 or B48 plugs?
No for a stock engine; they come pre-gapped at about 0.75 mm. Tuners may close the gap for high boost, at the cost of plug life.
What are the signs of worn spark plugs?
Misfire codes or a flashing check engine light, rough idle, hesitation under load, and sometimes a drivetrain malfunction message.