How much does a Mercedes A-Class W168 engine replacement cost in the UK?

A reconditioned W168 engine typically costs £1,200–£4,000 supply only, depending on engine — the volume M166 E14 petrol sits at £1,200–£2,200, while the M166 E21 A210 Evolution is the most expensive at £2,200–£4,000. Fitting adds £650–£1,000 depending on specialist rates. Use our calculator for a personalised figure.

Which Mercedes A-Class W168 engine is the most reliable?

The M166 E19 (A190, 1.9-litre petrol) is widely considered the pick of the range — offering 125 PS with fewer reported issues than the smaller 1.4-litre and 1.6-litre M166 variants. The OM668 diesel line is generally robust but injector and EGR wear is common on higher-mileage examples.

What are the common problems with the Mercedes A-Class W168?

Ignition coil failure on the M166 petrol engines, injector wear and EGR clogging on the OM668 diesels, and engine mount wear unique to the W168's sandwich-concept design. Cooling system leaks are also reported on higher-mileage A190 and A210 Evolution models.

Is the Mercedes A-Class W168 reliable?

Reliability is average for its era — the M166 petrol fours are simple and durable when maintained, while the OM668 diesel is robust but sensitive to injector health and short journeys. The W168's biggest reliability challenge is its age (most examples are now 20+ years old) rather than any fundamental design flaw.

Which Mercedes A-Class W168 engine should I avoid?

The OM668 diesel without documented injector service history is the one purchase we advise caution on — injector wear can lead to bore wash and turbo damage, a repair that frequently exceeds the car's value. The A210 Evolution is rare and desirable but parts are harder to find and more expensive.

How do I know if my W168 engine needs replacing?

Persistent misfires or rough idle on petrol engines (coil pack failure), poor cold starting or excessive smoke on diesels (injector/EGR issues), and loud clunking or vibration from the engine bay (worn mounts) are the key warning signs. Use our diagnostic calculator for a personalised assessment.

Is it worth replacing a Mercedes A-Class W168 engine, or should I scrap the car?

Depends on the car's value. Against a well-kept £4,000+ W168, a £1,800 M166 recon is 45% of the car's value — a serious but viable repair. Against a tired £1,500 example, the same recon is 120% — walk away. Our 70% Mercedes-Benz threshold is the line, but note that W168 values have started to rise for low-mileage, well-maintained examples.

How long do Mercedes A-Class W168 engines last?

The M166 petrol fours can comfortably exceed 150,000–200,000 miles with regular servicing and prompt coil pack replacement. The OM668 diesel can reach similar mileages but requires injector attention around 80,000–130,000 miles. The sandwich concept's engine mounts typically need replacement every 70,000–120,000 miles.

What is the difference between the W168 and W169 A-Class?

The W168 (1997–2004) is the first-generation A-Class — the one that failed the elk test and introduced the sandwich concept. The W169 (2004–2012) is the second generation, with revised styling, larger dimensions, and improved dynamics. Engines are generally not interchangeable between the two generations. See our W169 page for that generation's specifics.

How do I find my Mercedes A-Class W168 engine code?

Listed on the VIN plate (under the bonnet or on the driver's door pillar) and on the engine block itself — the M166 petrol engines are visible from above, while the OM668 diesel requires slight disassembly to access the block stamping. Tell us your variant (A140, A160, A190, A210, A160 CDI, A170 CDI) and we'll identify it — 25+ vetted Mercedes specialists will confirm it for free.

W168 Engine Replacement Cost UK

Mercedes A-Class W168 Engine Codes — The Complete Database

Every engine fitted to the W168 hatchback specifically — including the full M166 petrol range and the OM668 turbodiesel line.

Engine CodeFamilyFuelDisplacementPowerYears (W168)Variants (badges)Reliability2025 EnquiriesAvg. Recon Cost

M166 E14M166Petrol1.4L (1397cc)82 PS / 60 kW1997–2004A140★★★☆☆ [PROVISIONAL — pending dedicated Engine Page]— (pattern data)£1,200–£2,200 [PLACEHOLDER — confirm vs cost sheet]

M166 E16M166Petrol1.6L (1598cc)102 PS / 75 kW1997–2004A160★★★☆☆ [PROVISIONAL — pending dedicated Engine Page]— (pattern data)£1,400–£2,800 [PLACEHOLDER — confirm vs cost sheet]

M166 E19M166Petrol1.9L (1898cc)125 PS / 92 kW1999–2004A190★★★★☆ [PROVISIONAL — pending dedicated Engine Page]— (pattern data)£1,800–£3,500 [PLACEHOLDER — confirm vs cost sheet]

M166 E21M166Petrol2.1L (2084cc)140 PS / 103 kW2002–2004A210 Evolution★★★★☆ [PROVISIONAL — pending dedicated Engine Page]— (pattern data)£2,200–£4,000 [PLACEHOLDER — confirm vs cost sheet]

OM668 DE17 AOM668Diesel1.7L (1689cc)60 PS / 44 kW1998–2001A160 CDI★★★☆☆ [PROVISIONAL — pending dedicated Engine Page]— (pattern data)£1,500–£2,800 [PLACEHOLDER — confirm vs cost sheet]

OM668 DE17 LAOM668Diesel1.7L (1689cc)90 PS / 66 kW1998–2001A170 CDI★★★☆☆ [PROVISIONAL — pending dedicated Engine Page]— (pattern data)£1,800–£3,200 [PLACEHOLDER — confirm vs cost sheet]

OM668 DE17 LA (higher output)OM668Diesel1.7L (1689cc)95 PS / 70 kW2001–2004A170 CDI (facelift)★★★☆☆ [PROVISIONAL — pending dedicated Engine Page]— (pattern data)£1,800–£3,200 [PLACEHOLDER — confirm vs cost sheet]

Engine CodeFuelPowerYearsReliabilityEnquiriesAvg. Recon Cost

M166 E14M166Petrol82 PS / 60 kW1997–2004★★★☆☆ [PROVISIONAL — pending dedicated Engine Page]— (pattern data)£1,200–£2,200 [PLACEHOLDER — confirm vs cost sheet]

M166 E16M166Petrol102 PS / 75 kW1997–2004★★★☆☆ [PROVISIONAL — pending dedicated Engine Page]— (pattern data)£1,400–£2,800 [PLACEHOLDER — confirm vs cost sheet]

M166 E19M166Petrol125 PS / 92 kW1999–2004★★★★☆ [PROVISIONAL — pending dedicated Engine Page]— (pattern data)£1,800–£3,500 [PLACEHOLDER — confirm vs cost sheet]

M166 E21M166Petrol140 PS / 103 kW2002–2004★★★★☆ [PROVISIONAL — pending dedicated Engine Page]— (pattern data)£2,200–£4,000 [PLACEHOLDER — confirm vs cost sheet]

OM668 DE17 AOM668Diesel60 PS / 44 kW1998–2001★★★☆☆ [PROVISIONAL — pending dedicated Engine Page]— (pattern data)£1,500–£2,800 [PLACEHOLDER — confirm vs cost sheet]

OM668 DE17 LAOM668Diesel90 PS / 66 kW1998–2001★★★☆☆ [PROVISIONAL — pending dedicated Engine Page]— (pattern data)£1,800–£3,200 [PLACEHOLDER — confirm vs cost sheet]

OM668 DE17 LA (higher output)OM668Diesel95 PS / 70 kW2001–2004★★★☆☆ [PROVISIONAL — pending dedicated Engine Page]— (pattern data)£1,800–£3,200 [PLACEHOLDER — confirm vs cost sheet]

Overview

Mercedes A-Class W168 — Overview

The W168 is the first-generation Mercedes-Benz A-Class, launched in 1997 as the brand's entry-level model and its first front-wheel-drive passenger car.

It introduced the "sandwich concept" — a raised floorpan that allowed the engine to slide underneath in a collision. The engine range spanned M166 four-cylinder petrol units from 1.4 to 2.1 litres, plus OM668 1.7-litre turbodiesels, with a facelift in 2001 bringing updated power outputs.

Key Facts

Platform

Mercedes W168 (first generation)

Predecessor

None (first A-Class)

Successor

W169 (2004)

Sibling body styles in this generation

Five-door hatchback only (Vaneo MPV shared platform)

Market Intelligence

The W168 A-Class generated UK engine enquiries in 2025 [PATTERN DATA], with the OM668 diesel and M166 petrol fours remaining the most commonly discussed among specialists.

Mercedes A-Class W168 — Overview

The W168 is the first-generation Mercedes-Benz A-Class, launched in 1997 as the brand's entry-level model and its first front-wheel-drive passenger car.

It introduced the "sandwich concept" — a raised floorpan that allowed the engine to slide underneath in a collision. The engine range spanned M166 four-cylinder petrol units from 1.4 to 2.1 litres, plus OM668 1.7-litre turbodiesels, with a facelift in 2001 bringing updated power outputs.

Key Facts

Platform

Mercedes W168 (first generation)

Predecessor

None (first A-Class)

Successor

W169 (2004)

Sibling body styles in this generation

Five-door hatchback only (Vaneo MPV shared platform)

Market Intelligence

The W168 A-Class generated UK engine enquiries in 2025 [PATTERN DATA], with the OM668 diesel and M166 petrol fours remaining the most commonly discussed among specialists.

Best & Worst Engines

Thin-Data Summary

“Thin-Data Fallback mode — one paragraph: The W168's most dependable engine is the M166 E19 (A190) — the 1.9-litre petrol four offers 125 PS and is widely considered the pick of the M166 range for its balance of power and reliability. The M166 E21 (A210 Evolution) is the most powerful at 140 PS, but its rarity makes it a niche choice. The OM668 diesel line is generally robust but suffers from typical common-rail injector and EGR issues as mileage climbs. For most buyers, the A160 petrol (1.6L, 102 PS) represents the best value — cheap to run, simple to maintain, and free of the diesel's DPF-related complications. Avoid any W168 without documented service history, as the sandwich-concept engine layout makes labour more expensive than on conventional hatches.”

Who it's for:

Thin-Data Summary

“Thin-Data Fallback mode — one paragraph: The W168's most dependable engine is the M166 E19 (A190) — the 1.9-litre petrol four offers 125 PS and is widely considered the pick of the M166 range for its balance of power and reliability. The M166 E21 (A210 Evolution) is the most powerful at 140 PS, but its rarity makes it a niche choice. The OM668 diesel line is generally robust but suffers from typical common-rail injector and EGR issues as mileage climbs. For most buyers, the A160 petrol (1.6L, 102 PS) represents the best value — cheap to run, simple to maintain, and free of the diesel's DPF-related complications. Avoid any W168 without documented service history, as the sandwich-concept engine layout makes labour more expensive than on conventional hatches.”

Who it's for:

Mercedes A-Class W168 — Ownership Economics

EngineTypical MileageCommon Major FailureRepair Cost (Specialist)Replacement Cost (Recon)Ownership Verdict

M166 E14 (A140)80k–120kIgnition coil failure£150–£300£1,200–£2,200

Budget Choice — cheapest W168 to run

M166 E16 (A160)80k–120kIgnition coil, MAF sensor£150–£400£1,400–£2,800

Best Value — the sensible petrol choice

M166 E19 (A190)80k–120kThermostat housing leak£200–£400£1,800–£3,500

Most Reliable — the pick of the range

M166 E21 (A210 Evolution)60k–100kCooling system leaks£250–£500£2,200–£4,000

Rare Find — collectable but costly to maintain

OM668 DE17 A (A160 CDI)80k–130kInjector wear, EGR clogging£300–£600£1,500–£2,800

Solid Diesel — economy-focused choice

OM668 DE17 LA (A170 CDI)80k–130kInjector wear, turbo actuator£300–£700£1,800–£3,200

Best Diesel — more power, same reliability

EngineTypical MileageCommon Major FailureRepair Cost (Specialist)Replacement Cost (Recon)Ownership Verdict

M166 E14 (A140)80k–120kIgnition coil failure£150–£300£1,200–£2,200

Budget Choice — cheapest W168 to run

M166 E16 (A160)80k–120kIgnition coil, MAF sensor£150–£400£1,400–£2,800

Best Value — the sensible petrol choice

M166 E19 (A190)80k–120kThermostat housing leak£200–£400£1,800–£3,500

Most Reliable — the pick of the range

M166 E21 (A210 Evolution)60k–100kCooling system leaks£250–£500£2,200–£4,000

Rare Find — collectable but costly to maintain

OM668 DE17 A (A160 CDI)80k–130kInjector wear, EGR clogging£300–£600£1,500–£2,800

Solid Diesel — economy-focused choice

OM668 DE17 LA (A170 CDI)80k–130kInjector wear, turbo actuator£300–£700£1,800–£3,200

Best Diesel — more power, same reliability

The W168 rule

A £1,800–£3,200 recon on a sub-£2,000 W168 sits at 90–160% of the car's value — at that point, scrap value usually wins. Against a well-kept £4,000+ example, the same recon drops to 45–80% — still a serious decision, but one that can make sense if the car is otherwise sound. Value the car first, then the engine.

Key Takeaways

Which W168 Costs Least To Own?
A140 (M166 E14) — cheapest parts and simplest engine.
Which W168 Costs Most To Own?
A210 Evolution (M166 E21) — rare parts and cooling system complexity.
Which W168 Is Best Value?
A160 (M166 E16) — enough power, simple mechanics, widely available.

Common Problems

01

M166

Petrol Ignition Coil Failure

Affected models:

W168 A140, A160, A190 (all M166 petrol variants).

Typical failure mileage:

60,000–100,000 miles.

Root cause:

The M166's coil-on-plug ignition system is prone to coil pack failure, leading to misfires, rough idle, and reduced power. The issue is exacerbated by age and heat cycling in the tightly packed engine bay.

Tiered Cost Table

Preventative (Repair)

Dealer

Specialist

£300–£500

£150–£300

Replace faulty coil pack(s) and spark plugs

Catastrophic (Replacement)

Dealer

Specialist

£1,500–£2,500

£1,200–£2,200

Full engine strip and rebuild if misfire has caused bore damage

Our Recommendation

At the first sign of a misfire or rough idle, have the coil packs and spark plugs replaced — £150–£300 is cheap insurance against the £1,200+ replacement that follows if a persistent misfire damages the cylinder bore.

Compare M166 engine prices for your W168 A-Class

02

OM668

Diesel Injector Wear & EGR Clogging

Affected models:

W168 A160 CDI, A170 CDI (all OM668 diesel variants).

OM668 Diesel Injector Wear & EGR Clogging

Typical failure mileage:

80,000–130,000 miles.

Root cause:

The OM668's common-rail injectors wear over time, causing poor cold starting, increased smoke, and reduced fuel economy. The EGR valve clogs with soot, particularly on cars used for short urban journeys.

Tiered Cost Table

Preventative (Repair)

Dealer

Specialist

£500–£900

£300–£600

Injector refurbishment, EGR cleaning

Catastrophic (Replacement)

Dealer

Specialist

£2,500–£4,000

£1,800–£3,200

Full replacement of injectors, EGR, and DPF if damaged

Our Recommendation

Use premium diesel and give the car a regular motorway run to keep the EGR and DPF clear — a £300 injector service every 80,000 miles is far cheaper than the £1,800+ replacement that follows if injector wear leads to bore wash or turbo damage.

Compare OM668 engine prices for your W168 A-Class

03

Sandwich

Concept Engine Mount Wear

Affected models:

All W168 variants.

Typical failure mileage:

70,000–120,000 miles.

Root cause:

The W168's unique "sandwich" design mounts the engine at a 59-degree angle just behind the front axle. The engine mounts and subframe bushes wear over time, causing clunking, vibration, and misalignment that can accelerate drivetrain wear.

Tiered Cost Table

Preventative (Repair)

Dealer

Specialist

£500–£800

£300–£500

Replace engine mounts and subframe bushes

Catastrophic (Replacement)

Dealer

Specialist

£1,200–£1,800

£900–£1,400

Full subframe removal and reinforcement if mounts have failed completely

Our Recommendation

Have the engine mounts inspected at every service after 70,000 miles — £300–£500 in preventative work is a fraction of the £900+ cost if worn mounts cause subframe damage or drivetrain misalignment.

Compare W168 engine mount replacement quotes

W168 Engine Replacement Costs — By Engine and Condition

VariantEngine CodeUsed (Supply)Reconditioned (Supply)Rebuilt (Supply)Labour Hours

A140M166 E14£600–£1,200£1,200–£2,200£1,800–£3,0008–12 hrs

A160M166 E16£700–£1,500£1,400–£2,800£2,200–£3,8008–12 hrs

A190M166 E19£900–£1,800£1,800–£3,500£2,800–£4,50010–14 hrs

A210 EvolutionM166 E21£1,200–£2,200£2,200–£4,000£3,500–£5,50010–14 hrs

A160 CDI (60 PS)OM668 DE17 A£700–£1,400£1,500–£2,800£2,500–£4,00010–14 hrs

A170 CDI (90/95 PS)OM668 DE17 LA£900–£1,600£1,800–£3,200£2,800–£4,50010–14 hrs

Core Variants

Diesel Variants

A160 CDIA170 CDI

Petrol Variants

A140A160A190A210 Evolution

Scope note: All variants listed are W168 five-door hatchback only. The W169 (second generation) and Vaneo (MPV variant) share some engines but are covered on their own pages.

Core Variants

Diesel Variants

A160 CDIA170 CDI

Petrol Variants

A140A160A190A210 Evolution

Scope note: All variants listed are W168 five-door hatchback only. The W169 (second generation) and Vaneo (MPV variant) share some engines but are covered on their own pages.

Market Intelligence

Most Requested E90 Engines (2025)

Most Requested E90 Variants

Average E90 Replacement Cost

Most Common E90 Failures

FAQ

BMW 3 Series E90 rear three-quarter view

Why UK Mercedes A-Class W168 Owners Trust MercedesEngines.uk

Trusted W168 Engine Suppliers
every garage and engine rebuilder in our network is vetted, rated and reviewed by real Mercedes owners, as part of the Engine Finders network. We only work with specialists who understand the W168's unique sandwich-concept layout.
Compare W168 Engine Replacement Companies
see prices, warranty terms and supply & fit options side-by-side before you commit. Whether you need a reconditioned M166 or a used OM668, we show you the real market.
UK Engine Replacement Services for W168
covering every variant from A140 to A210 Evolution, with supply-only or full supply & fit available nationwide through our vetted specialist network.

Find the best Mercedes A-Class W168 engine replacement UK drivers rely on. Compare real prices from trusted specialists on EnginesMarket today and get back on the road with confidence.

Compare Mercedes A-Class W168 Engine Prices on EnginesMarket

Why UK Mercedes A-Class W168 Owners Trust MercedesEngines.uk

Trusted W168 Engine Suppliers
every garage and engine rebuilder in our network is vetted, rated and reviewed by real Mercedes owners, as part of the Engine Finders network. We only work with specialists who understand the W168's unique sandwich-concept layout.
Compare W168 Engine Replacement Companies
see prices, warranty terms and supply & fit options side-by-side before you commit. Whether you need a reconditioned M166 or a used OM668, we show you the real market.
UK Engine Replacement Services for W168
covering every variant from A140 to A210 Evolution, with supply-only or full supply & fit available nationwide through our vetted specialist network.

Find the best Mercedes A-Class W168 engine replacement UK drivers rely on. Compare real prices from trusted specialists on EnginesMarket today and get back on the road with confidence.

Compare Mercedes A-Class W168 Engine Prices on EnginesMarket

Mercedes A-Class W168 Engines — The Complete UK Guide

Mercedes A-Class W168 Engine Codes — The Complete Database

Mercedes A-Class W168 — Overview

Mercedes A-Class W168 — Overview

Best & Worst Engines

Mercedes A-Class W168 — Ownership Economics

Common Problems

W168 Engine Replacement Costs — By Engine and Condition

Core Variants

Core Variants

Market Intelligence

FAQ

Why UK Mercedes A-Class W168 Owners Trust MercedesEngines.uk

Why UK Mercedes A-Class W168 Owners Trust MercedesEngines.uk