Are OM654 injector problems common?

Less common than the OM651 due to the newer design. Most issues appear after 80,000+ miles.

How much does OM654 injector replacement cost?

A single remanufactured injector costs £250-£400. Labour is 2-3 hours. Full set: £1,000-£1,600 plus labour.

Do OM654 injectors need coding?

Yes. IMA coding via Star Diagnostic or compatible tool is mandatory.

How much does it cost to replace injectors?

Replacement typically costs £150–£350 per injector depending on brand and engine. A full set of four with professional fitting usually costs £600–£1,200.

Can I drive with a faulty injector?

Driving with a faulty injector can cause engine damage, increased fuel consumption, DPF contamination, and oil dilution. We recommend diagnosis and replacement as soon as possible.

Do new injectors need coding?

Some vehicles require injector coding after replacement using manufacturer-specific diagnostic tools. Many Bosch solenoid units are plug and play. Check your engine guide for specific requirements.

Why is my diesel injector knocking?

Diesel injector knocking is typically caused by worn nozzle tips that alter the fuel spray pattern, leading to harsher combustion. Carbon buildup, incorrect injection timing, and high fuel pressure can also contribute. A professional leak-off test can confirm whether injectors are the cause.

Can a bad injector cause white smoke?

Yes. A faulty injector that dribbles fuel instead of atomising it causes incomplete combustion, producing white or grey smoke. This is especially noticeable on cold starts and typically clears as the engine warms up.

How long do diesel injectors last?

Most diesel injectors last between 80,000 and 150,000 miles depending on fuel quality, driving conditions, and maintenance. Regular fuel filter changes and using quality diesel can extend their lifespan.

Will injector cleaner fix misfire?

Injector cleaner may help with minor carbon deposits, but it cannot fix worn nozzles, failed solenoids, or internal seal leaks. If misfire persists after using cleaner, professional testing and likely replacement is needed.

Mercedes OM654 Injector Problems: Symptoms & Replacement Guide (UK)

Updated for 2026 diagnostics & repair guidance

Successor to the OM651. More advanced but injector parts are more expensive.

The OM654 replaced the OM651 as Mercedes' primary 4-cylinder diesel. It features aluminium construction, stepped-bowl pistons, and a new Nanoslide cylinder coating. Injector issues are less common than the OM651 but emerge at higher mileage.

OEM tested & calibrated12-month warrantyFree UK deliveryNo coding required (most models)

OEM Tested
12-Month Warranty
Free UK Delivery

Registration Lookup Find Matching OM654 Injector

Drivers also ask

Quick Diagnosis

If your OM654 engine shows:

rough idle
hard starting
white or black smoke
knocking or ticking noise
reduced fuel economy

A faulty injector may be the cause. Continue below to confirm symptoms and solutions.

Can You Drive With This Problem?

Driving short distances may be possible, but continued use can cause:

piston damage
turbo contamination
fuel dilution of engine oil
catalytic converter damage

Prolonged driving may lead to major engine failure.

Typical Repair Costs (UK)

Average costs for injector-related repairs:

£180 - £350

Per Injector

£700 - £1,200

Full Set (4)

£120 - £300

Labour

Early replacement prevents costly engine damage.

Common Injector Failure Symptoms

Owners frequently report:

Subtle idle roughness

The OM654 is extremely refined — even minor injector deviation produces noticeable roughness compared to normal.

AdBlue warning alongside injector codes

Poor combustion increases NOx, triggering SCR warnings that can mask the underlying injector fault.

DPF regeneration frequency increase

Worn injectors increase soot production, causing more frequent DPF regeneration events.

Cold start hesitation

Injectors that fail to atomise correctly during pilot injection cause brief cranking hesitation.

Full symptom guide White smoke guide

Fault Codes Linked to Injector Issues

Common diagnostic codes include:

P0201-P0204Injector circuit malfunction

P2002DPF efficiency below threshold (secondary symptom)

P20EESCR NOx catalyst efficiency below threshold

Misfire diagnosis guide

How to Diagnose OM654 Injector Faults

Follow this step-by-step testing approach to identify the faulty injector:

1
Read fault codes
Connect an OBD-II scanner and note any injector-related codes (P0201–P0204, P2146, P2149). This identifies which cylinder is affected.
2
Perform a leak-off test
Disconnect the fuel return pipes and route into measuring containers. Run the engine at idle for 60 seconds. Compare volumes per cylinder against manufacturer spec.
3
Listen for injector tick
Use a mechanic's stethoscope on each injector body. A dead or irregular tick indicates a stuck or failing solenoid.
4
Check fuel rail pressure
Monitor live fuel rail pressure data via diagnostic tool. Low pressure can mimic injector symptoms and may indicate a fuel pump issue instead.
5
Inspect for external leaks
Check around injector seals for signs of fuel or combustion gas leakage. Black carbon deposits indicate a blown seal.
6
Cylinder balance test
Use diagnostic software to run a cylinder contribution test. This electronically disables each injector in turn to measure its effect on engine speed.

Full leak-off test guide Injector coding guide

Why OM654 Injectors Fail

Common causes include:

fuel contamination
high-pressure wear cycles
carbon buildup
poor fuel quality
internal valve wear

Professional remanufacturing restores spray pattern and pressure accuracy.

When Replacement Is Required

Injector replacement is recommended if:

leak-off test fails
misfire persists after coding
excessive return flow detected
spray pattern fails testing
vehicle enters limp mode

OM654 Repair Advice

The OM654 requires IMA coding via Star Diagnostic after injector replacement. The aluminium cylinder head requires careful torque control.

Remanufactured (Recommended)

OEM-spec rebuild with new nozzles, seals, and solenoids. Full flow testing. 12-month warranty. 40–60% less than new.

Brand New OEM

Factory-fresh from Bosch, Delphi, or Siemens. Highest cost but zero previous wear. Best for low-mileage vehicles.

Vehicles Using the OM654 Engine

This engine is commonly found in:

Mercedes-Benz C220d

W205 · 2016-2021

Mercedes-Benz E220d

W213 · 2016-2021

Mercedes-Benz GLC 220d

X253 · 2019-2022

Mercedes-Benz Sprinter 314 CDI

W907 · 2018-present

Professional Installation Tip

Always:

replace copper sealing washers
torque injectors to manufacturer specification
clean injector seats before installation
code injectors after installation (if required)

Leak-off test guide Injector coding guide

Compatible Injector Part Numbers for OM654

The following injector part numbers are commonly associated with OM654 engines:

0445110571BoschA6540700100Mercedes-Benz

OM654 Injectors — Shop Now

In-stock injectors listed first for fastest delivery:

MERCEDES GLC-CLASS ( GLC 220 D 4Matic SE Auto X253) 2.1L 2015-2018 Diesel Injector

£200.00

Made to order12 months

MERCEDES GLC-CLASS ( GLC 220 D 4Matic SE Executive Auto X253) 2.1L 2015-2018 Diesel Injector

£200.00

Made to order12 months

MERCEDES GLC-CLASS ( GLC 220 D 4Matic Sport Auto C253) 2.1L 2016-2019 Diesel Injector

£200.00

Made to order12 months

MERCEDES GLC-CLASS ( GLC 220 D 4Matic Sport Premium Auto C253) 2.1L 2016-2019 Diesel Injector

£200.00

Made to order12 months

MERCEDES GLC-CLASS ( GLC 250 D 4Matic AMG Line Auto X253) 2.1L 2015-2019 Diesel Injector

£200.00

Made to order12 months

MERCEDES GLC-CLASS ( GLC 250 D 4Matic AMG Line Premium Auto C253) 2.1L 2016-2019 Diesel Injector

£200.00

Made to order12 months

MERCEDES GLC-CLASS ( GLC 250 D 4Matic Sport Auto C253) 2.1L 2016-2019 Diesel Injector

£200.00

Made to order12 months

MERCEDES GLC-CLASS ( GLC 300 AMG Line Premium D 4Matic Auto X253) 2L 2019- Diesel Injector

£200.00

Made to order12 months

View all OM654 injectors

These injectors are commonly used with the OM654 engine. Confirm compatibility using your engine code or registration lookup before ordering. Our team can verify the correct part for your specific vehicle.

Helpful Guides

Reconditioned injectors guide

How remanufactured injectors are tested & warranted

Injector warranty guide

What's covered & how to claim

UK delivery & fitment help

Free next-day delivery & part-number checks

Find Your Exact OM654 Injector

Three quick ways to confirm the right part:

Registration Lookup

Enter your reg to find the exact part

Engine Code Search

Search using OM654

Same-day dispatch before 2pm12-month warranty includedOEM tested & calibrated

Not sure which injector? Call us on 020 3355 6581.

Frequently Asked Questions

Injector Symptoms

Spot the warning signs of a failing diesel injector

Injector Fault Codes

P0201–P0204 injector circuit codes explained

Smoke Diagnosis

White & blue smoke causes and fixes

Injector Testing

Leak-off & bench testing methods

Replacement Cost

UK parts + labour cost breakdown

Misfire Diagnosis

Why injectors cause rough running & misfires

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Remanufactured Injectors

OEM-rebuilt, every wear part replaced, 12-month warranty

Reconditioned Injectors

Bench-tested, calibrated, UK same-day dispatch

Refurbished Injectors

Cleaned, nozzle-replaced, flow-tested — cheaper than reman

Used Diesel Injectors

Read this before you buy — risks, checks, real cost

Buyer-intent comparisons

Remanufactured vs New

Same lifespan, 40–60% cheaper — when reman wins, when new wins

Replacement Cost UK 2026

Parts + labour + coding — per-engine UK pricing tables

Best Place to Buy UK

7 quality signals, warranty wording, core-return checks

Mercedes OM654 Injector Problems: Symptoms & Replacement Guide (UK)

Drivers also ask

Quick Diagnosis

Can You Drive With This Problem?

Typical Repair Costs (UK)

Common Injector Failure Symptoms

Subtle idle roughness

AdBlue warning alongside injector codes

DPF regeneration frequency increase

Cold start hesitation

Fault Codes Linked to Injector Issues

How to Diagnose OM654 Injector Faults

Read fault codes

Perform a leak-off test

Listen for injector tick

Check fuel rail pressure

Inspect for external leaks

Cylinder balance test

Why OM654 Injectors Fail

When Replacement Is Required

OM654 Repair Advice

Remanufactured (Recommended)

Brand New OEM

Vehicles Using the OM654 Engine

Professional Installation Tip

Compatible Injector Part Numbers for OM654

OM654 Injectors — Shop Now

Helpful Guides

Find Your Exact OM654 Injector

Frequently Asked Questions

Related Guides

Related Engine Problems

Other Engine Guides

Related commercial guides

Buyer-intent comparisons