Mercedes Sprinter and Vito Turbo Repair and Rebuild

This page is for Sprinter and Vito owners, fleet engineers and the garages that look after their vans, when a four-cylinder CDI has lost boost, started smoking or begun to whine. It goes from the engine to the turbocharger, sets out what the two-stage units change, and finishes with how we rebuild them. The 3.0 V6 is a different engine with different turbochargers and is not covered here.

Which Sprinter or Vito Engine Is in Your Van?

Three four-cylinder diesel families sit under the Sprinter and Vito badges, and each brought its own turbochargers. The table summarises the fitment data we work from. The years are the years each unit is catalogued against, not the full production run of either van.

Two points follow. The engine family decides which row your van belongs to, and within each family more than one turbocharger is listed. The label on the turbocharger is what settles it, so photograph it before the unit is cleaned or packed.

2.1 or 2.2 CDI: the listing size is not a guide

Sellers describe these engines as 2.1 or 2.2 with no consistency, and trade fitment data does the same. The OM651DE22LA appears under both a 2.1 and a 2.2 Sprinter heading, the Vito’s 651950 engine is filed under both, and the OM646 engine code 646982 turns up in both Vito lists. Mercedes’ own engine designation carries a 22 even where a listing says 2.1.

So a “Sprinter 2.1 CDI turbo” and a “Sprinter 2.2 CDI turbo” in two adverts can be the same part, and two parts under one heading can be entirely different. Search and match on the turbocharger reference, never on the engine size in the title.

Single Turbo or Two-Stage: The 2.1 CDI Arrangement

A two-stage turbocharger is two turbochargers built to work as one assembly. As a general principle of two-stage turbocharging, a smaller unit builds boost quickly at low engine speed and a larger one takes over as exhaust flow rises, with valves dividing the gas between them. On the OM651 the catalogue lists the pair as a BorgWarner KP39 and a K04; it does not describe how the two are arranged or controlled on this engine.

The same pairing appears once on the older engine. The Sprinter on OM646 engine code 646986 is catalogued with a K04, 5304-970-0057, and a KP39, 5439-970-0049, against the same outputs, and the replacement trade sells the two as a set. OM646 Sprinters of similar power on engine code 646985 are catalogued with a Garrett GTB1749VK instead, so on a van of that age the six-digit engine code is what separates the two layouts.

The K04 stage belongs to the BorgWarner family described on our BorgWarner K03 and K04 turbo repair page, which explains how those frame sizes are designated.

One number, three amounts of hardware

The two-stage unit is where Sprinter and Vito turbo numbers stop being straightforward, because a number in circulation can describe three different things.

• The whole assembly. A 1000-970 reference such as 1000-970-0036 or 1000-970-0074 is catalogued as the KP39 and the K04 together.
• One stage, named by its position. The same 1000-970 number with (I) or (II) after it names a single stage. On every Vito row that carries a suffix, (I) is the KP39 and (II) is the K04.
• One stage, named by its own reference. Each stage also has a number of its own, 5439-970 for the KP39s and 5304-970 for the K04s in these listings, and those appear as separate catalogue rows against the same OM651 engines.

Sellers do not keep the three apart. One specialist sells the complete two-stage pair for the OM651 Sprinter on a listing referenced 53049700086, a number our fitment data gives to a single K04. Order on the number alone and you can be quoted for half the unit you need, or pay for a whole assembly to replace one stage.

So record every number on every label, including any suffix, and note whether the turbocharger you are looking at is one unit or two joined together. If you are sending the unit itself for rebuild, none of this has to be resolved first. We identify what arrives on the bench and rebuild exactly that.

What Fails on Sprinter and Vito Turbochargers

Every unit in the table shares the same core. A turbine wheel and a compressor wheel sit on one shaft, which turns in oil-fed journal bearings inside a centre housing, with a sealing ring at each end. The makers differ; the ways these cores wear do not.

• Bearings and thrust surfaces. Short, overdue or dirty oil wears them first. Radial play lets the wheels move towards their housings, and end float lets the shaft shift along its own axis. Left running, either ends with a wheel touching its housing.
• Sealing rings. Once the shaft moves more than it should, the rings stop holding oil inside the centre housing, and it passes into the intake or the exhaust. Oil in the charge pipes is usually the first thing anyone sees.
• Variable vanes. Where a turbocharger controls boost with a ring of variable vanes, as many diesel units do, carbon on that ring makes boost late or absent while the rotating assembly is still sound. Our Garrett GT2052V turbo repair page explains how the vane mechanism works and fails.
• The actuator that moves the vanes. On versions with an electronic actuator, the actuator can fail rather than the turbocharger. If a cool-down restart clears the fault for a while, read our Sprinter and Vito actuator repair page before the turbo comes off.
• Two-stage assemblies. Each stage wears as a turbocharger in its own right, so one can be worn while the other measures within limits. The valve work between the stages can also stick, which looks like a failed turbocharger when both rotating assemblies are healthy.

Most of these failures start on the van rather than in the turbo: a carboned oil feed, a return line that drains slowly, a split intake hose letting grit reach the compressor, or oil changes stretched too far. A rebuild renews what wore. It cannot correct the cause, and a cause left on the van will wear the rebuilt unit the same way.

Symptoms on a Working Van

A van shows a failing turbocharger when it is asked for boost, and it is asked hardest fully laden, on a long gradient or with a trailer behind. A Sprinter that drives normally empty around the yard has not passed a test. Drive it the way it works before deciding the fault has cleared.

• Loss of power or limp mode, often with P0299 or P0234 stored. Each records a disagreement between the boost asked for and the boost measured, not a failed part; our guide to turbo overboost and underboost codes explains what the two can and cannot tell you.
• A new whine, siren or rasp that rises and falls with the turbo. Our guide to diagnosing a turbo whistle separates the noises that come from the unit from those that do not.
• Blue or grey smoke, or oil use climbing between services.
• Oil in the charge pipes or intercooler, found when a hose is taken off.
• On a two-stage unit, boost missing in one part of the rev range only. The stage that does most of the work at those engine speeds is the first suspect, but the valves between the stages can produce the same symptom, so treat it as a clue rather than a verdict.

Two cheaper faults imitate turbo failure on these vans often enough to rule out first. A charge hose can split on the inside of a bend and open only under boost, so it hides at idle; soapy water on the hoses while someone raises the revs helps, but a loaded road test tells you more. And oil carried over from the crankcase ventilation system can coat the intake side and look exactly like a turbocharger passing oil.

Once the noise turns metallic or oil smoke is visible, stop working the van hard. Every loaded mile after that point moves more of the unit out of the rebuild column and into the replacement column. Our guide to turbo failure symptoms sorts the signs by where in the unit they start.

Rebuild or Replace on a High-Mileage Van?

Big mileages are normal on a Sprinter or Vito, and the question they raise is not whether the turbo is too old to save but what else has worn with it. Four things decide the route.

• What the number buys. A replacement for a two-stage unit has to be the right assembly or the right stage of it, from a trade that labels the two loosely. A rebuild returns the unit that came off, so there is nothing to match.
• Whether one stage or both need work. If one stage has worn and the other measures within limits, rebuilding the worn one alone is usually the economical route.
• How much of the unit survived. When the turbine wheel, shaft and a housing have all failed inspection, little of the original is left to rebuild. In that case a replacement is often the better value, and we say so rather than rebuild a unit that should be replaced.
• Whether the cause has been found. A restricted oil feed or a split intake hose will wear a new unit as surely as a rebuilt one.

Rebuilds start from £185, and replacement units from us start from £450. Neither includes removing and refitting the turbocharger, and a rebuild price is confirmed once the unit has been stripped and measured. What moves a rebuild up its range is set out in our guide to van turbo repair prices.

If you know the van’s year and power output, our rebuild listings for the Sprinter 2.1, Sprinter 2.2, Vito 2.1 and Vito 2.2 let you order on those two facts. Given the 2.1 and 2.2 overlap above, choose by year and power rather than by the size in the title, and we confirm the unit on the bench either way.

Our Sprinter and Vito Turbo Rebuild

You, or the garage that looks after the van, remove the turbocharger and send it to us at Unit 102 Reaver House, 12 East Street, Epsom, Surrey, KT17 1HX, United Kingdom. Independent garages and main dealers send units for their customers’ vans the same way. The work runs in this order.

1. Complete the online Repair Form. Give the registration, the engine code if you have it, the power output, mileage, symptoms and any fault codes. On a two-stage unit, list every number from every label, with any (I) or (II).
2. Remove and pack the unit. Send a two-stage assembly together as it came off; if only one stage is coming, label which it is. Cover every port. Our guide to removing, refitting and priming a turbocharger covers the job on the van, and packing and postage are on our FAQs page.
3. Identification and strip. The unit, and on a two-stage assembly each stage, is identified from its labels, or on the bench where heat has made them unreadable. It is then stripped to component level by turbo specialists who rebuild turbochargers and turbo actuators as their core work.
4. Measurement and renewal. The shaft, wheels, bearing bores and housings are cleaned and measured against original specification. Bearings, thrust parts and sealing rings are renewed with genuine OE or OEM-grade components that meet or exceed the original, and a part with a known design weakness is uprated rather than put back.
5. Boost control. Vanes, valves or wastegate on the unit are cleaned and freed where sound and renewed where worn, so boost control moves as designed.
6. Balanced, bench-tested and returned. The rotating assembly is balanced, and the unit is set up and run on the bench before it is boxed and sent back, ready to refit.

Bench time is typically one to three working days from arrival, with postage each way on top. Every rebuild carries a lifetime, unlimited-mileage warranty, with no time limit and no mileage cap. On refitting, renew the oil feed and return lines rather than reusing them, and prime the oil feed before the engine first runs, so the renewed bearings are never turned dry.

Mercedes Sprinter and Vito Turbo FAQ

Final Thoughts

On the OM611 and on most OM646 vans, a Sprinter or Vito turbo number meant one turbocharger. The two-stage units changed that. A reference can now mean the complete assembly, one stage by its position or one stage by its own number, and the trade uses all three without saying which.

The answer is not to become an expert in BorgWarner numbering. Write down everything on the labels, find out why the unit wore before another goes on, and if you send the turbocharger itself, the question of which number buys what never has to be answered at all.