Diesel Mercedes Sprinter Turbo Rebuild

 
The Garrett variable vane turbocharger (Garrett GT18V VNT and its derivatives) are fitted to the diesel Mercedes Sprinter van and most of the modern range of light commercials and passenger cars with very little difference in design, so this post generally covers all but a very few of the turbochargers currently used in Mercedes turbo diesel vehicles. There is more information available on the Turbocharger control circuit, Limp Home (LOS) Faults and component descriptions here: http://www.mercedes.gen.in/WP35/mercedes-sprinter-turbo-limp-home-los-diagnosis-fault-finding/

You will no doubt be aware of the huge replacement cost of a Turbo, and often used parts prices escalate into a ‘tear welling’ hit into the wallet.  I decided to rebuild my turbocharger at home using an aftermarket core kit, overhauling the complete unit as a result.  The core kit cost is £150.00 – an incredible cost saving for what will be a good as new turbo.  Here’s how it went…

Mercedes Garrett Turbo Rebuild

Mercedes Turbo Model Plate

Mercedes sprinter turbo damage

Damaged Turbo Spool

One of the first things you will need to find is the model number of your turbocharger, the core supplier will need this number to match identical parts to your rebuild.  The model number is engraved on a flat plate on the aluminium intake scroll casting, you may need some fine abrasive paper to clean it so that it is visible.

Mercedes Sprinter Turbo Rebuild

Garrett Variable Vane Turbocharger

Mercedes turbo core

New Replacement Turbo Core

The Garrett variable vane turbocharger works by modulating the pitch of a number of vanes within the exhaust scroll casting, these vanes direct or concentrate the flow of the exhaust gasses onto one end of the turbo charger spool.  The more concentrated the flow of gas the faster the spool spins.  The vanes are adjusted by the rotation of a control ring and lever that is connected to an external actuator. (Commonly a vacuum actuator on early vehicles and an electronic positional servo motor on some later models variants)  By varying the control to the actuator, the turbo vanes can be called into play or requested to idle by the engine management system.   The turbo spool shaft passes from the exhaust chamber of the turbo through a series of seals and high speed oil cooled bearings to the intake side where it drives an opposing spool wheel that compresses intake air at a rate controlled by the passage of exhaust gasses – the faster the assembly rotates on the exhaust side the greater intake charge pressure is generated.

Garrett turbo charger rebuild

How it works – gas flows

The turbo I had on the bench had failed catastrophically, the spool shaft had disintegrated and destroyed both spool wheels, eventually shearing the shaft into two parts.  I was now about to rebuild the unit to ‘as new’ serviceable condition.  The removal of the turbo from the vehicle had previously been done, its far safer to remove the complete exhaust manifold with turbo connected, than to risk removing the three turbo to manifold flange bolts, that will almost certainly shear off in the process.  You have been warned !

Remove the actuator from the turbo and set it aside, mark the location of the aluminium intake scroll flange and plate then remove all the 8mm washer-bolts from the flange edge.  Once all the bolts are removed tap the housing to free off the flange and remove the intake scroll. (Clean parts off as you go!)

Mercedes turbo intake scroll

Intake air turbo scroll casting

Then remove the flange bolts and washers from the exhaust scroll.  Use penetrating oil or diesel soaked into the flange seam to assist in freeing it off.  Tap gently the housing with a copper faced hammer or wooden block, working your way around the circumference.  Eventually it will come away.  Be sure to watch for the large vane adjusting ring and the three small guide pins and wheels that secure it to the internal plate.  Don’t worry where they came from at this stage as it can only go back together one way, just catch the parts and do not lose them!

Now that the exhaust scroll housing is removed the main scroll and vane section can be treated generously to a can of Mr Muscle oven cleaner or similar, to soften and help free off the internal components that will be coated with soot and carbon deposits.  Do not use oven cleaner on the alloy intake scroll as it will be attacked by the spray cleaner – just use cleaner on the cast iron or steel parts.  Once rinsed off with water begin a further clean up the steel parts.

Garrett turbo charger strip down

Adjustable vane turbo. Internal actuating levers

Remove the three torx head screws securing the vane plate to the scroll housing, as you lift out the ring vane plate be sure to catch the three spacers from behind.  Put these spacers in a safe place, along with the torx screws.  Clean off as much of the carbon deposits from the vanes, vane ring and housing as possible and remove all scrapings etc.  Be sure to clean/scrape all the flange locating grooves to make sure that when things are seated on reassembly, components flush fit without binding or rocking.

Garrett turbo vanes

Removing carbon deposits from vanes

Mercedes Sprinter Turbo strip down

Cleaned exhaust scroll casting

Mercedes turbo internal vane components

Cleaned turbo vane ring

Once all the parts are as clean as you require begin the reassembly.  Start by refitting the vane ring to the exhaust scroll, using the three torx screws and spacers put to one side earlier.  Now look around the flange face for a single small drilling that locates the spool core roll pin stake.  This is the locator of the vane actuating ring positional slot engaging with the lever mechanism that passes through the spool housing to the outside world.  Position all the vane levers in their associated slots in the adjusting ring, then position the three slotted guide wheels and axle pins into their place on the ring vane plate.  Check the rotary movement and actuation of all the vanes by turning the inner ring back and forth, almost no resistance to movement should be felt in the mechanism.

Mercedes sprinter turbo rebuild

Adjustable vane assembly rebuilt

You are now ready to fit the new turbo core.  Align the vane adjusting ring with the flange roll pin hole and hold the external vane actuating lever on the new core in the correct position whilst pushing together and locating the flange.  The core exhaust face should now be a comfortable push fit and have located flatly against the scroll flange, with equal lip protrusion all around its circumference.  Once you are sure all is well and it is assembled correctly, check the vane actuating lever for correct operation. You should just about be able to see the vanes move between the new turbo spool wheel and the inside of the exhaust scroll housing – using a torch makes this easier.  Begin to tighten down the ring bolts and washers evenly.  Now is the time to replace the actuator and fit it to the actuator lever, as the fixing bolts form part of the flange clamping arrangement. Refit the actuator lever arm circlip and adjust the lever stop to exactly the same position (protrusion) as the original stop on the discarded old core. (8mm spanner and small ball end hex key to adjust)

Turbo actuator lever

Turbo actuator lever and stop adjustment

DSC_1445 DSC_1446 DSC_1447

Sprinter turbo core rebuild

New turbo core fitted to exhaust scroll casting

Now you can fit the intake scroll casting to the new core assembly.  Noting the location marks you made before disassembly on the alloy flanges, replace the scroll casting in the correct position and secure with the ring of 8mm washer head bolts, tightening evenly and steadily as you go.

Mercedes Turbo Diesel Turbo Rebuild

Completed rebuilt Mercedes turbo assembly

Everything is now back together, notice the added oil return pipe, this had been cleaned with paraffin and a ‘pull through’ made from a piece of rag on string.  Fit a new fibre gasket to this pipe and finger tighten only, the free end has to be orientated into the sump pocket and this can severely hamper the replacement of the exhaust manifold if otherwise tightened.  Save the last return pipe fixing ‘nip-up’ until its all in position on the vehicle. (Its a pig to get to, but it is possible with a stubby 1/4 drive 8mm socket and short extension from beneath the vehicle)

Mercedes Sprinter turbo core

New Mercedes turbocharger core fitted

Once the assembly is totally rebuilt and fitted to the vehicle, it needs to be ‘primed’ with oil before the engine is run.  I have found the best way to do this is to position the oil feed pipe and use a syringe to squirt engine oil into the turbo core before fitting the banjo bolt and washers.  Then take a screwdriver and slide-disconnect the electrical plugs to the four injectors on the cylinder head.  (This will prevent the vehicle starting before priming is completed)  After checking the oil feed banjo bolt is tight and having tightened the drain return pipe fasteners, crank the engine in 15 second bursts, 30 seconds waiting – 7 or 8 times.  This should initially prime the turbo oil ways ready for engine starting.   All text books and manuals say:  ”to check oil prime, remove oil return pipe, crank engine without firing and wait for oil to emerge….”  in reality the return pipe is virtually impossible to remove or refit with the turbo in place so the above method was substituted.  Do feel free to remove the pipe and watch for oil as per the manuals and instructions if you wish!  Once ready for starting clip back the injector electrical plugs, start the engine and allow it to idle for a few minutes without revving.  Once happy that all is well, reconnect the vac pipes and hose work that was removed to the allow turbo removal and road test.

I hope this saved you some money !

23 thoughts on “Diesel Mercedes Sprinter Turbo Rebuild

    1. Hi Jay,
      Give these people a call, make sure you quote the full long part number on your turbo body. Prices start from about £150.00 plus shipping.
      Good quality parts at the some of the best pricing.

      Rapid Turbo’s
      North Yorkshire
      Phone:07527|776564 Email:rapidturbos@live.co.uk

  1. Hi steve,

    I am new to this site I was searching on sprinter 316cdi year 2010 some limp mode problem then only I found your site. I must say the information you are sharing are very useful.
    I like to ask you about the problem I am facing. Van is in limp mode but when we conect with diagnostic equipment we dont find any fault code stored but when I try to diagnose on eobd I found code p2bac I dont know about this. Can you share any information on it.

    1. Hi Sameer,
      The modern Sprinter really needs a compatible code reader to accurately extract the correct codes from the ECU, using a DIY OBD2 type reader could mislead you. However a P2BAC code refers to NOX Exceedence – Deactivation of EGR, in other words the EGR is not functioning or is being held off. The first practical thing you can do is to check the EGR valve itself. Either blocked, sticking or just faulty – not uncommon problem on later NCV3 Sprinters. I would also consider what part controls the NOX system and that will be the NOX sensor, chances are this is faulty causing the EGR to stop functioning. Due to the high cost of the NOX sensor, I would be tempted to get the van read with a MB STAR reader at a dealer, purely to conclude it was definitely the fault and not some other related DPF issue before parting with your hard earned cash!
      Hope that helps a little
      All the best Steve

      1. Hi steve,

        Thanks for reply. EGR valve replaced with new one but still the van is in limp mode. Engine is not running more then three thousand rpm.
        Sameer

      2. Hi Sameer,
        The 3000 rpm limit is all part of Limp-mode. All noted on the new EGR valve, you will now need to investigate the NOX sensor and check its wiring for damage as I mentioned before, it may be in your financial favour to at least let the dealer or good commercial independent with the correct diagnostics equipment, pin-point the fault, as the cost of the NOX sensor (if it is faulty) is a few hundred pounds just for the part!
        All the best
        Steve

  2. Hi Steve, my 05 213cdi sprinter turbo simply stops completely. No limp mode or warning indicator. Van goes ok, just very low power. No apparent reason. Leave him overnight and works perfectly again. It is a La Strada camper conversion with only 42k on the clock. Has happened several times in past month.
    Any ideas?

    Ps. Brilliant website, well done for all your effort!

    1. Hi Jerry,

      Thanks for the accolade!

      First port of call would be – visually check all the hose work connected from the turbo to intercooler onward to the inlet manifold, once you are satisfied that is all good, check he condition of the air filter ( http://www.mercedes.gen.in/WP35/not-maintaining-sprinter-air-filter-can-leave-stranded/) finally change the fuel filter to an OEM original part. The other common fault is the brake light switch above the pedal, this will hold off the power and not flag a dash warning lamp.

      All the above are best guess solutions, it could be one of them or not a one! You really need to get the van read with a capable code reader, this will reveal any ‘stored codes’ that may lead you to the problem far more quickly and economically than ‘parts-darts’ hoping to score a bullseye.

      Let me know how you get on with the cheap and cheerful first base solutions.

      All the best
      Steve

  3. Hello-I am replacing a turbo on a 311cdi Sprinter-Ive unbolted the turbo but cant pull the oil return pipe from the sump-do you just keep pulling ??

      1. Got it out ok -thanks–main shaft is broken-thinking of just getting a rebuilt one rather than changing just the core–any advice on a supplier–or there are people in Germany who sell new pattern parts on Ebay UK for £300–what do you think –van is 2004 Sprinter 311cdi and done about 110 K
        Many thanks

  4. I am in Thailand. I am working at S.N. Autoline .co.th about repaires Mercedesbenz
    My customer use mercedesbenz vito w639 and now I scan comperterized turbocharged that wate.
    I would to buy new turbocharged. not exchanged not repair
    How much price of new turbo ?
    include vat , shipping to Thailand

    Mercedesbenz Chasiss no WDD 639 705 236 286 30
    PART NUMBER TURBO = A646 090 15 80

    Thanks

    1. Hi Sukit,
      The turbo you need is made for Mercedes by Garrett and is model number – VV19
      Contact these people that are possibly able to supply Garrett direct, as well as compatible new units. It it will be cheaper than through Mercedes network. http://www.aet-turbos.co.uk/find-my-turbo/mercedes-vito-111-cdi-2007-2011-ihi-rhf4v-replacement-turbo-a6460901380 I am unsure if they will be able to help you with shipping to your base as they are located in the UK, but it could be possible that by email they would know of a Garrett supplier in Thailand.

      Garrett Honeywell distributors are located here in Thailand, give them a call:
      Authorized Garrett® Distributors

      World Tech
      3/64 Moo 2, Chaloemphrakiag
      Ratchakan Thi 9 Rd.
      Prawet, Bangkok
      10250
      Tel: 66 2 726 0001 4
      Fax: 66 2 726 0005 6
      vilas@worldtech.co.th

      Here are the Garrett / Mercedes cross reference part numbers you may need. http://www.btnturbo.com/parts/model/mercedes/vito/bhp116/2007_om646982_5114.aspx

      Hope this helps
      Steve

  5. Hi,
    That is an excellent description and pictures for the turbo job. I may well be having a go, but I suspect only the oil seal. I have a Merc 1999 108cdi minibus. I suspect a leak from the turbo bearing seal. It is burning oil and has signs of blue smoke when cold. had the rings replaced, head job done, reconned injectors and diesel pump.
    On the turbo rebuild is it necessary to balance the impeller wheels?

    1. Hi Terry,
      The turbo impeller is a precision balanced device and to choose a complete cartridge, ready built and tested is really the only other acceptable way to refurbish the turbo save buying a complete replacement. I think the reason the seals are probably worn on your turbo could be due to a little more bearing play than is optimal wearing the sealing surfaces – on reflection if you had the equipment to hand to just ‘re-seal’ it you would probably have the same issues not too far down the road.
      All the best
      Steve

  6. Hi, I have a 2004 311 Sprinter I use in the summer only for about 2000 miles year, it has 132k on the clock and as I carry a model traction engine weighing 750kg and a 1500kg caravan it is always fully loaded.
    it passes its test every year and pulls ok considering its around 5 tonne or just over gross. however even running light the turbo wines all the time. constantly in all gears at all loads. should I be worried and consider changing the turbo or keep running it to see if it fails.

    Stuart

    1. Hi Stuart,
      I would keep an ear on it! Some turbos do run noisy for years, not just on some Sprinters but for instance L200 Mitsubishi is a very vocal turbo. If there is no smoke, no excessive oil consumption then carry on. Should the noise increase or limp home starts affecting your driving routine investigate further. My advice, if all the above check out OK _ don’t repair what isn’t broken!
      Best Regards
      Steve

  7. Hi Steve,

    thank you for your reply, the engine does not use excessive oil, about three years ago I had the oil light come on during a long run, I pulled off and topped up straight away but it was a one off. there is no smoke, it does not use too much fuel, it always passes its test, it starts every time and as yet I have never had the limp mode come on and I have owned the van for about 8 years. I will take your advice and keep it running as is. its now laid up until next May-June.

    Stuart.

  8. I tried this and now its back together but the vane adjuster is kind of tight once it was
    assembled. I cant see the vanes through the turbo like you said so not sure if its
    actually adjusting the vanes.

    The lever will move but it takes a lot of force to move. You said it is
    easy to move before assembly which it was. But you didnt say if it
    tightens up when installed.

    1. Hi JD

      It sounds like the the sliding ring mechanism is not engaged correctly in the dog-bone lever that is attached to the end of the actuating lever. It will move without any force at all once clean and engaged properly, You should see what is going on with the vane edges from the exhaust side of the turbo scroll with an inspection mirror and torch.
      All the best
      Steve

  9. Hi. I have a 2002 sprinter 311 cdi with about 140k on the clock. I changed the water pump this weekend due to a leak. This seemed to have cured that problem. Due to time pressure I didn’t get a chance to give it a good run to check everything out before putting it to work this evening. Fully loaded and pulling a 1.5 tonne digger I had travelled a few miles and heard a big ‘whoosh’. Stopped, checked for leaks , loose pipes, things falling off etc but couldn’t see anything. Travelled a bit further and whenever I put my foot down a bit a lesser ‘whoosh’ happened again. The noise seemed to come from the engine through the heating vents. Of course, there’s little power. I presume it’s something to do with the turbo but any ideas what it could be or what I need to check out?
    Many thanks in anticipation

    1. Simon, Check the big pipe that runs to the inlet manifold, look under it as it often splits directly underneath the bit that runs over the fan! Black oil deposits will give any leak away, be sure to check the side tanks on the intercooler to.

      All the best
      Steve

      1. Many thanks for your reply Steve. I have been meaning to post an update but have been stupidly busy.

        I found the problem the following morning. The lower hose to the intercooler had popped off. I obviously loosened it when changing the water pump without removing it and forgot to re tighten it.

        Moral of the story. Check my work properly, do a test run before needing it for an important job, don’t look for the cause of the problem when stressed and when it’s getting dark.

        At least I’ve learnt a bit about the turbo system.

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