About this model
The Mercedes Vito W639 is the second generation of the Vito, produced from 2003 to 2014, and one of the most commonly seen working and family vehicles in BiH. In Banja Luka we see it as a taxi, as a company van, as an eight-seater family van and as a passenger V-class with leather and added insulation. Most examples that come into our workshop are the 2.2 CDI with the OM646 engine (109/111/115 CDI, up to 2010) or the OM651 (110/113/116 CDI, the 2010-2014 facelift). The Vito is popular in BiH because it combines mechanical reliability, good parts availability and a large supply of used examples imported from Germany, Austria and Italy. The mileages we see are almost always over 250,000 km, which means the faults listed here are not an exception but a predictable course of events.
Engines and variants
In BiH this model is most commonly available with the following engines.
OM646 - 2.2 CDI (109/111/115). Pre-facelift engine (2003-2010), rated at 88, 110 or 120 kW, with Bosch or Delphi injectors. The most reliable choice in the W639 range, but above 200,000 km the Delphi injectors typically fail ("black death") along with the plastic flaps in the intake manifold. The timing chain is at the front of the engine and usually lasts the full engine life with regular oil changes. This is the engine most often chosen by taxi drivers and companies that want the smallest maintenance headache, and parts are available both original and in a quality aftermarket offering.
OM651 - 2.1 CDI (110/113/116). Facelift engine (2010-2014) with second-generation Common Rail, a new alternator and AdBlue/SCR system on later examples. It is more powerful and more economical than the OM646, but with a noticeably more problematic timing chain (guides and hydraulic tensioner at the rear of the engine towards the gearbox) and a CP4 high-pressure pump that is sensitive to poor diesel. Anyone choosing the OM651 has to plan for an intervention around 200,000 km, but in return gets noticeably better fuel economy and a more comfortable drive on long trips.
OM642 - 3.0 CDI V6 (122). A six-cylinder 3.0 V6 diesel from the same family as in the E-class and ML, mostly seen in V-class and Viano variants (2006-2014). A powerful and pleasant engine for passenger trim levels, but prone to the known V6 issues: oil cooler that leaks onto the block, EGR system and worn turbos. It is not for those who want the cheapest maintenance, but for those who choose it for comfort and power, it is worth the effort with regular servicing and attention around 250,000 km.
Reliability and reputation on the BiH market
The Vito W639 is a workhorse that people in Banja Luka mostly bought for business: taxi, delivery, transporting workers, families with lots of children. Used examples are mostly of German origin, with mileage between 250,000 and 500,000 km, which is not exceptional for the Vito but the rule. Parts are available, original through Mercedes, but also with strong availability of quality aftermarket parts (Mahle, Bosch, Pierburg, Febi) at significantly more favourable prices. Compared to the VW T5, which is its direct competitor, the Vito has healthier core mechanics and better chassis parts, but the T5 has a better cabin and simpler electronics package. Anyone buying a Vito has to accept that this is a vehicle that needs regular servicing, it is not a "fill it with fuel and drive" car. Investing in a proper major service and timely chain or injector replacement always pays off compared to the cost of a full overhaul that arrives when everything is neglected at once.
Common faults we see
From practice, here is what most often comes in for repair on this model.
1. Timing chain and guides (especially OM651)
Symptom: Rattling from the rear of the engine on cold start, rough idle, occasional correlation fault between camshaft and crankshaft.
The OM651 has the chain at the rear of the engine (towards the gearbox), and the problem is not the chain itself but the plastic guides and hydraulic tensioner, which give up between 150,000 and 250,000 km depending on oil change intervals. The OM646 is much healthier in this respect, but it is not flawless at high mileage either. Replacement on the OM651 means dropping the gearbox, which is a serious job and should never be postponed once the first symptoms appear.
Advice: On every Vito W639 with an OM651 engine we do a borescope inspection and a cold-start listening test before the owner accepts an offer - diagnosis before it stops on you.
2. Injectors (Delphi/Bosch) and "black death"
Symptom: Hesitation when pulling away, power loss, rough idle, smoke, occasional P0201-P0204 faults. Fuel leaking around the injector that forms the characteristic black crust together with carbon - the so-called "black death".
Typically above 180,000-200,000 km, especially on the OM646 with the Delphi setup. Poor diesel in BiH and short trips speed up the problem. If not addressed in time, the carbon can damage the cylinder head around the injector cup and multiply the repair cost.
Advice: Injectors can be reconditioned: bench test, cleaning, new nozzles and copper washers. Do not wait for the channels in the head to start burning.
3. EGR valve and EGR cooler
Symptom: Power loss above 2000 rpm, smoke, engine light with P0401/P0402 faults, increased fuel consumption, sharper acceleration after manual cleaning.
The Vito mostly works in town and mixed driving with a lot of idling and short trips - ideal for clogging the EGR system with soot. The EGR cooler can crack and let coolant into the intake, which gives white smoke and a drop in the coolant reservoir without any visible leak under the car.
Advice: Regular EGR cleaning in the 80,000-100,000 km range, depending on driving style, and if a cracked cooler is suspected, a coolant system pressure test is mandatory.
4. Turbocharger (Garrett VNT), vanes and actuator
Symptom: Power loss above 2500 rpm, P0299 fault (underboost), whistling, sometimes smoke and oil in the intercoolers and intake hoses.
The variable-geometry turbo is sensitive to carbon and poor oil. Vans that carry loads and do cold starts without regular oil changes are the first candidates for stuck vanes. The electric actuator on the OM651 can fail on its own without any physical fault in the turbo itself.
Advice: Actuator adaptation and calibration plus turbo decarbonisation before an expensive replacement - this often fixes the problem if you react in time.
5. DPF filter (and AdBlue on later examples)
Symptom: DPF light, forced regeneration every few hundred kilometres, failed regeneration attempts, increased fuel consumption.
The Vito is a working tool, it spends a lot of time idling with the engine running (taxi, delivery, construction site), and that is the worst thing for a DPF. Later OM651 models also have the AdBlue/SCR system, which has its own problems: crystallisation on the heater and false AdBlue consumption.
Advice: A DPF can be cleaned if it is done before it fills up past 80 percent of permanent ash. A 30-minute motorway run once a week is the cheapest prevention.
6. Dual-mass flywheel and clutch
Symptom: Vibrations at idle, rattling when starting and shutting the engine, occasional hesitation when pulling away, clatter from the clutch pedal.
The Vito often carries loads and tows, so the dual-mass flywheel takes much more abuse than in an ordinary passenger car. Typical life is in the 200,000-280,000 km range depending on driving style and load, shorter if the vehicle is used as a company van with hard launches. On variants with the seven-speed 7G-Tronic the situation is a bit better, but the manual five-speed and six-speed have the classic dual-mass set.
Advice: Always replaced together with the clutch and release bearing, "half a job" should never be done because labour is 90 percent of the bill.
7. High-pressure pump (CP1H/CP4)
Symptom: Hard hot start, floating idle, power loss under load, recurring rail pressure faults (P0087, P0088).
The OM646 has a Bosch CP1H pump which is relatively robust, while the OM651 moves to the CP4, which is more sensitive to fuel quality and lubrication. Poor diesel in BiH can chew metal shavings off the pump that then circulate through the entire rail and kill the injectors - a very expensive scenario if not caught in time.
Advice: Fuel filter strictly every 30,000 km, never wait "until it starts knocking", and if there is any suspicion, always check the return flow on the injectors before condemning the pump outright.
8. Rear wheel bearings and parking brake
Symptom: Humming that grows with speed and gets louder in corners; parking brake that "sticks" or no longer holds a full load.
The W639 has a known weakness in the rear wheel bearings, especially when the van is heavily loaded. The parking brake is foot-operated and the cables run through a drum inside the disc - corrosion in the BiH climate will inevitably block the mechanism if it is not lubricated.
Advice: At every rear disc and pad change we check the parking brake shoes and lubricate them - it costs an hour of labour and saves an expensive repair later.
9. Sliding door, runners, locks and motor
Symptom: Door catches in the middle of its travel, does not lock with the remote, slams loudly when closing, does not open on a slope.
The sliding door on the Vito is a working part - it opens and closes dozens of times a day for taxi drivers and businesses. The lower runner collects dirt and road salt, the upper rollers wear out, and winter is particularly problematic. The central lock with the electric motor is a typical fault after 200,000 km and is usually replaced as a complete unit.
Service and maintenance
The Vito 2.2 CDI has no timing belt, both engines (OM646 and OM651) have a chain, which does not mean "for life". The chain on the OM646 usually lasts the full engine life with regular oil, while the guides and tensioner on the OM651 need attention in the 180,000-220,000 km range depending on service intervals. We use oil meeting MB 229.51 or 229.52 specification in 5W-30 viscosity with intervals of 10,000-15,000 km depending on type of use. We never go to the factory 25,000 km in BiH conditions, especially not on vehicles with a DPF. Fuel filter strictly every 30,000 km, AdBlue (if the vehicle has it) is checked at every service, and the EGR valve on the OM651 is preventively cleaned in the 80,000-100,000 km range.
Which oil for the Vito W639 2.2 CDI
For both engines (OM646 and OM651) we look for oil with MB approval 229.51 or 229.52 in 5W-30 viscosity. These are so-called "low-SAPS" oils, compatible with the DPF and SCR system, and without them the DPF fills up with ash that cannot be cleared by regeneration much more quickly. The brands we regularly use in the workshop are Mobil 1 ESP, Shell Helix Ultra ECT, Total Quartz Ineo and Castrol Edge Professional, all in the same specification. The key thing is that the specification is printed on the can, because 5W-30 with the wrong approval (e.g. 229.31 or 229.5) does not belong in these engines.
Owner tips
- Before buying a specific example: use the VIN to pull the full vehicle history through carVertical. From international registers the report usually shows real odometer figures with dates, recorded accidents, number of previous owners and theft or total-loss indicators. We consider it mandatory before buying any used Vito, especially with German and Italian imports that have been used as working vehicles. When paying for the report you can use the code GAGA to get a 20% discount.
- MB 229.51 or 229.52 oil in 5W-30 strictly every 10,000-15,000 km, never go to the factory 25,000 km in Banja Luka conditions.
- Fuel filter every 30,000 km, the CP4 pump on the OM651 does not forgive poor diesel and shavings from an old filter that get into the rail.
- Drive the Vito on the motorway for at least 30 minutes once a week to let the DPF finish its regeneration - taxi work and short trips clog it in record time.
- On the OM651, around 180,000 km do a borescope check of the timing chain - diagnosis before failure costs an hour, while replacing the chain with the gearbox out is a big job.
Frequently asked questions
Which engine is the better choice, OM646 or OM651?
For reliability and simple maintenance the OM646 has the edge - its chain is at the front, the injectors are more accessible and there are no AdBlue complications. The OM651 is a more modern and more economical solution with better performance, but it needs more attention around 200,000 km because of the chain and the CP4 pump. If you are buying the Vito as a workhorse without any appetite for expensive repairs, the OM646 is the safer choice.
Is the Vito W639 2.2 CDI reliable for 400,000 km?
Yes, but only with regular and serious servicing - it is not a car that forgives neglect. We have seen Vito W639s that have gone past 500,000 km on the original engine, but every one of them has had the injectors replaced, the dual-mass done, EGR cleaning and timely DPF treatment. Without those interventions, the engine stops well before that.
Is it worth fitting LPG on the Vito 2.2 CDI?
No, the Vito 2.2 CDI is a diesel engine, and LPG is only fitted to petrol engines. If you want a Vito with LPG, you have to look for the rare petrol variants (3.2 V6, 3.5 V6) which are almost never seen in BiH. To reduce fuel consumption on a diesel Vito it is more effective to work on injector maintenance, EGR and tyre pressures.
How long does the dual-mass flywheel last on the Vito W639?
From our experience, the dual-mass on the Vito lasts in the 200,000-280,000 km range depending on load and driving style, which is somewhat shorter than the same engine in an E-class because the Vito works under load more often. It is always replaced as a set with the clutch and release bearing - the labour is the same, and it saves time and money in the long run.
Is the 7G-Tronic gearbox in the Vito reliable?
Yes, provided that the oil is changed every 60,000-80,000 km, never on the factory "lifetime" interval. We have seen problems with the electrohydraulic module (mechatronics) and oil that turns black and goes past its limit, usually accompanied by slipping during shifts. The manual five-speed and six-speed gearboxes are simpler and more durable.
What most often causes trouble on the Vito's sliding door?
The lower runner that collects dirt and salt, the upper rollers that wear out and the central lock with an electric motor that fails. Most issues are solved by cleaning and lubricating the runner, but if the car spends a lot of time outside, the mechanics wear faster. The electric sliding doors on V-class and Viano variants have an additional motor and controller that can fail.
How much does a major service on the Vito W639 2.2 CDI cost?
A major service (oil, all four filters, coolant, brake fluid) for the Vito 2.2 CDI is a one-day job. The price depends on the actual condition and oil choice - get in touch for an estimate. The biggest costs come from irregular servicing that piles up into a single visit after two years, because that is when injectors, EGR, DPF and the dual-mass all arrive at once.
If you notice any of these symptoms on your Vito, drop by the workshop - it is better to check it early than to repair it expensively.