Mercedes Benz Viano 3.0 CDI / 3.5 CDI Engine ReplacementCompare Prices & Get Quotes
Get quotes today from trusted UK Mercedes Benz Viano 3.0 CDI and 3.5 CDI engine specialists. Compare prices on reconditioned, rebuilt and used OM642 V6 diesel engines - supply & fit available nationwide.
Supply & Fit Available
12-Month Warranty
Nationwide Delivery
100+ Suppliers
From £2,200 to £3,800
Used from £1,200 · Reconditioned from £1,800 · Common codes: OM642.890, OM642.990
From £1,200
Tested, bare/short engine
From £1,800
Rod bearings addressed, tested
From quote
Upgraded bearings, full teardown, revised valvetrain
Secure enquiry - no spam, no pressure. Genuine quotes only from vetted UK Mercedes Benz Viano 3.0 CDI and 3.5 CDI specialists.
3 Simple Steps3 Simple Stepsto Finding the Best Mercedes Benz Viano 3.0 CDI / 3.5 CDI Replacement Engineto Finding the Best Mercedes Benz Viano 3.0 CDI / 3.5 CDI Replacement Engine
Most replacements completed within 3-5 days.
Variant HistoryMercedes Benz Viano 3.0 CDI / 3.5 CDI - Engine History & Specs at a Glance
The Mercedes Benz Viano 3.0 CDI and 3.5 CDI represent the premium diesel options in the W639 Viano range, powered by the OM642 3.0-litre V6 turbodiesel - a smooth, refined engine that delivered 204hp in early models and 224hp in facelift versions, offering superior torque and refinement over the four-cylinder 2.2 CDI units.
Variant HistoryMercedes Benz Viano 3.0 CDI / 3.5 CDI - Engine History & Specs at a Glance
The Mercedes Benz Viano 3.0 CDI and 3.5 CDI represent the premium diesel options in the W639 Viano range, powered by the OM642 3.0-litre V6 turbodiesel - a smooth, refined engine that delivered 204hp in early models and 224hp in facelift versions, offering superior torque and refinement over the four-cylinder 2.2 CDI units.
Mercedes Benz Viano 3.0 CDI / 3.5 CDI
Fuel TypeDiesel
Engine Size3.0L (2,987cc)
Power Output Range204-224hp across the variant's historyEngine History Timeline
Viano 3.0 CDI introduced with OM642.990 3.0L V6 diesel 204hp (150kW), 5-speed automatic transmission
Marco Polo camper variant offered with same OM642.990 engine
W639 facelift introduces upgraded OM642.890 with 224hp (165kW) 440Nm torque, 5G-Tronic or 7G-Tronic transmission
Viano production ends replaced by Mercedes V-Class
Key Specs Snapshot
Fuel TypeDieselEngine Size3.0L (2,987cc)Power Output Range204-224hp across the variant's historyTorque Range440-440NmYears Produced2006-2014Every OM642 V6 diesel engine fitted to the Mercedes Benz Viano 3.0 CDI and 3.5 CDI is covered below, with UK rebuilt pricing and known failure points from real owner experience.
Mercedes Benz Viano 3.0 CDI / 3.5 CDI Engine Codes - Specifications & Replacement CostMercedes Benz Viano 3.0 CDI / 3.5 CDI Engine Codes - Specifications & Replacement Cost
3.0L V6 Diesel (2006-2010)
Power Output204 hp (150 kW) @ 3,800 rpmTorque440 NmDisplacement2,987ccConfigurationV6, 72° V-angle, common-rail direct injection, light-alloy block, 4 valves per cylinderYears Fitted2006-2010
Compatible Trim Levels
- Viano 3.0 CDI
- Viano 3.0 CDI Ambiente
- Viano 3.0 CDI Marco Polo
Find your exact engine code, specs and UK replacement cost guide.
Used
Tested, ready-to-fit engine
£1,200-£2,200
Reconditioned
Addressed known issues, tested
£1,800-£2,800
Rebuilt
Full teardown, upgraded internals
£2,200-£3,500
Common Failure
The OM642's oil cooler seals (A6421880480) degrade over time, allowing oil to leak into the inner-V of the engine. This is a labour-intensive repair (8-12 hours) as access requires extensive disassembly. Turbocharger inlet seal leaks and EGR cooler cracking are also documented.
The Mercedes Viano 3.0 CDI and 3.5 CDI rely on the OM642 V6 diesel - a smooth and refined engine that delivers effortless torque, but has developed a well-documented reputation for specific, expensive failures. Oil cooler seal leakage is the dominant replacement driver, while turbocharger oil seal failure and EGR cooler cracking also feature prominently. Every rebuilt engine supplied through EnginesMarket includes upgraded components designed to address the original failure point - plus a minimum 12-month unlimited mileage warranty. Below we break down the most common Viano 3.0 and 3.5 CDI engine failures, what they cost to fix, and when replacement is the smarter financial decision.
Why the Viano 3.0 / 3.5 CDI Leaks Oil
Affected Vehicles
Mercedes Viano 3.0 CDI, 3.5 CDI (OM642.990, OM642.890, 2006-2014)
Typical Failure Mileage
70,000 - 150,000 miles
Root Cause
The oil cooler seals (A6421880480) sit deep in the "V" of the OM642 V6 engine between cylinder banks. These rubber seals degrade over time, allowing oil to leak down the back of the engine and onto the driveway. The seals themselves cost under £10 - but accessing them requires 8-12 hours of labour. A Mercedes Service Bulletin (LI18.30-P-055434) addresses this known issue.
Why It Happens
The oil cooler seals (A6421880480) sit deep in the "V" of the OM642 V6 engine between cylinder banks. These rubber seals degrade over time, allowing oil to leak down the back of the engine and onto the driveway. The seals themselves cost under £10 - but accessing them requires 8-12 hours of labour. A Mercedes Service Bulletin (LI18.30-P-055434) addresses this known issue.
Dealer (parts + labour)
£1,400-£2,200
Specialist (parts + labour)
£800-£1,400
What it involves
Replacement of oil cooler seals, intake manifold gaskets, and related seals while accessible
Suitability
70k-150k miles; engine remains sound after repair
1 - 2 daysDealer (parts + labour)
£4,000-£6,000
Specialist (parts + labour)
£2,200-£3,800
What it involves
Supply & fit reconditioned OM642 with new seals, upgraded components, and warranty
Suitability
Only necessary if oil starvation has caused bearing damage
1 - 2 daysAll prices are indicative UK market ranges based on current UK specialist supplier data.| Repair Tier | Dealer (Parts + Labour) | Specialist (Parts + Labour) | What It Involves | Suitability | Estimated Time |
|---|---|---|---|---|---|
 Oil Cooler Seal Replacement Minor | £1,400-£2,200 | £800-£1,400 | Replacement of oil cooler seals, intake manifold gaskets, and related seals while accessible | 70k-150k miles; engine remains sound after repair | 1 - 2 days |
 Full Replacement - Rebuilt OM642 Engine Best Value | £4,000-£6,000 | £2,200-£3,800 | Supply & fit reconditioned OM642 with new seals, upgraded components, and warranty | Only necessary if oil starvation has caused bearing damage | 1 - 2 days |
Vehicle Value Check
Vehicle Value Check
A typical W639 Viano 3.0 or 3.5 CDI is worth £4,000-£12,000 depending on condition and mileage - the full replacement cost of £2,200-£3,800 is modest relative to vehicle value for most examples. For vehicles worth under £4,000, evaluate repair options first.
Our Recommendation
Our Recommendation
This is an expensive job for what seems like a minor leak - but it's a known, predictable failure on the OM642. Don't ignore it; oil loss can lead to belt contamination and eventual engine seizure. Use a reputable Mercedes specialist (£800-£1,400) rather than a dealer. If caught early with no engine damage, the seal replacement is the correct fix.
Don't Let Engine Failure Write Off Your Mercedes Viano 3.0 or 3.5 CDI
A failed OM642 V6 engine doesn't have to mean the end of your Viano. Whether you're dealing with oil cooler seal failure, turbocharger oil leaks, or EGR cooler issues, EnginesMarket makes it simple to compare prices from trusted UK Mercedes Viano specialists. Every rebuilt engine in our network includes upgraded components designed to address the original failure point, a minimum 12-month unlimited mileage warranty, and nationwide delivery with supply & fit options available.
Compare rebuilt OM642 engine prices for your Viano 3.0 / 3.5 CDI
12-Month Minimum
UK Specialists Vetted
Best Price GuidanceImportant Information
Important Information
"All prices are indicative UK market ranges based on historical quote data and repair requests from our network of engine specialists. Dealer pricing is estimated based on published main dealer labour rates and genuine OEM parts pricing. Specialist pricing reflects actual quote data from EnginesMarket's UK network. Actual costs vary depending on damage severity, vehicle condition, variant, and workshop location within the UK. Use our free comparison tool to get tailored quotes for your specific Mercedes Viano 3.0 CDI or 3.5 CDI. Every engine supplied through EnginesMarket carries a minimum 12-month unlimited mileage warranty - always confirm exact terms with your chosen supplier."
Mercedes Viano 3.0 CDI / 3.5 CDI Engine ReplacementFrequently Asked Questions
Question 1How much does a Mercedes Viano 3.0 or 3.5 CDI engine replacement cost in the UK-
A Viano 3.0 or 3.5 CDI engine replacement typically costs between £2,200 and £3,800 depending on condition type and whether fitting is included. OM642 V6 units range from £2,200 to £3,800 supply only.
- Rebuilt OM642 (Viano 3.0 / 3.5 CDI): £2,200-£3,800 supply only
- Reconditioned units: £1,800-£3,200
- Used engines from breakers: £1,200-£2,500 but higher risk
- Labour for supply & fit adds £400-£800 to any engine price
Question 2What is the most common failure on the Viano 3.0 and 3.5 CDI OM642 engine-
The OM642 V6 diesel's most common failure is oil cooler seal degradation - the seals cost under £10, but accessing them requires 8-12 hours of labour.
- Oil cooler seals (A6421880480) fail between 70k-150k miles
- Oil leaks from the inner-V of the engine - often dripping onto the bell housing
- Mercedes Service Bulletin LI18.30-P-055434 covers this issue
- If ignored, oil loss can lead to belt contamination and engine seizure
Question 3Is the OM642 engine in the Viano 3.0 and 3.5 CDI reliable-
The OM642 is fundamentally a strong, refined engine - but it has one significant weakness: the oil cooler seals.
- The engine block and internals are exceptionally durable
- Oil cooler seal failure is predictable and expensive to repair
- With preventative maintenance, these engines regularly exceed 200,000 miles
- Many high-mileage OM642 Vianos remain in commercial and private hire service
Question 4What are the signs of OM642 oil cooler seal failure in a Viano 3.0 or 3.5 CDI-
The OM642's oil cooler seals typically show warning signs before complete failure.
- Oil spots on the driveway beneath the engine area
- Burning oil smell from the engine bay - oil dripping onto hot components
- Low oil level warnings between services
- Oil residue visible in the inner-V of the engine (visible with inspection)
- If ignored, oil contamination of the belt tensioner can cause sudden failure
Question 5Should I repair or replace my Viano 3.0 or 3.5 CDI engine-
Repair if the failure is isolated (e.g., oil cooler seals, turbo inlet seal, EGR cooler). Replace if there's bottom end damage, bore scoring, or catastrophic oil starvation.
- Oil cooler seal replacement at specialist: £800-£1,400 - catch it early
- Turbo inlet seal replacement: £250-£450 - preventative maintenance
- Full OM642 rebuild: £2,200-£3,800 - for catastrophic failure or 120k+ miles
- Given Viano 3.0 / 3.5 CDI values (£4,000-£12,000), a rebuilt engine is typically good value
Question 6How do I know which engine code my Viano 3.0 or 3.5 CDI has-
Check your vehicle log book (V5C) for the engine number, which includes the engine code prefix.
- V5C log book shows full engine number with code prefix
- Engine code stamped on cylinder block
- Viano 3.0 CDI (2006-2010): OM642.990 (204hp)
- Viano 3.0 / 3.5 CDI (2010-2014): OM642.890 (224hp)
- Service history documents list engine type
Question 7Can I fit a used Viano 3.0 or 3.5 CDI engine myself-
We strongly advise against DIY fitting on a Viano 3.0 or 3.5 CDI. The OM642 V6's weight, W639 subframe geometry, and ECU coding requirements demand specialist equipment and expertise.
- V6 engine weight requires proper lifting equipment
- Subframe must be lowered - not a driveway job
- ECU coding and immobiliser synchronisation required
- Specialist supply & fit costs £400-£800 - essential for a V6
Question 8What warranty comes with a reconditioned Viano 3.0 or 3.5 CDI engine-
Every engine supplied through EnginesMarket carries a minimum 12-month unlimited mileage warranty, with many specialists offering 24-month coverage on OM642 rebuilds. This includes parts and labour for any manufacturing defect or installation error.
- 12-month unlimited mileage is the minimum standard
- OM642 rebuilds often include 24-month warranty
- All warranties cover parts, labour, and MOT compliance
- Extended warranties available at point of purchase
Why Choose UsCompare Mercedes Viano 3.0 / 3.5 CDI V6Engine PricesToday
100+ Viano V6 engines supplied through our network
12-Month Warranty on every rebuilt Viano 3.0 and 3.5 CDI engine
Nationwide UK delivery
supply & fit available
Comparing quotes for your Mercedes Viano 3.0 or 3.5 CDI engine replacement is completely free and carries no obligation - enter your registration above, receive tailored prices from UK specialists who know the OM642 V6 diesel engine inside out, and get back on the road with confidence. Every rebuilt engine is backed by a minimum 12-month unlimited mileage warranty.
Enter your registration
and get matched with verified Mercedes Benz Viano 3.0 CDI / 3.5 CDI specialists.