0445120538 Common Rail Injector for Mercedes Actros

The applications we stand behind for this injector are the Mercedes-Benz Actros and Actros MP4 diesels of about 12.8 litre diesel displacement — the platform catalogued under that label in reseller fitment data, working in tractors and rigid trucks. On a Mercedes-Benz truck running the Actros family, this is the common rail injector the engine was built with, and a truck injector order that starts from the etched number rather than the model badge is the one that arrives correct. That is a tight, well-evidenced list, and an 0445120538 belongs to it and to nothing else we can back. Some parts catalogues extend the list further, to FAW Jiefang truck engines and to equipment from other makers; those entries are catalogue data we do not assert, and the engine code plate plus the old injector settle them in a minute if your machine is one of them. A mercedes-benz actros injector order that starts from the number on the removed unit almost never goes wrong; an order that starts from a machine model list sometimes does.

Why the removed injector matters more than the model list. Engine families run several injector numbers across years, ratings and emissions revisions, and two machines with the same model badge can take different parts. The hex etching on the old unit is the ground truth: it carries the injector number and the bracketed code together, and it survives in the darkest corner of the engine bay long after the paperwork is gone. Match that, then match the plate, then order. A Mercedes-Benz Actros injector bought this way arrives correct the first time, which is the whole point of the four steps above.

What this page is not claiming. We are not saying that any neighbouring number in the Bosch 0 445 120 series fits, that the catalogued truck applications are covered without a plate check, or that an injector from another engine family will substitute. 0445120538 is the injector for the Actros-family applications published against it, and the cross-listed Bosch number 0445120296 describes the same unit on those engines. Anything beyond those lines is better answered from your own parts data, and we would rather answer it with you than assert it here.

A diesel engine with a common rail system separates fuel pressurisation from fuel delivery. A high-pressure pump fills a rail that stays at pressure, and each common rail injector draws from that rail — the rail pressure itself is held by the pump and regulated by the control module, so it does not fall when one injector opens — and meters fuel into its own cylinder, in the quantity and at the moment the control module commands. As a common rail injector for Mercedes-Benz Actros engines, this unit answers to exactly that description and to nothing narrower. The Actros engines work exactly that way, and the injector is the part that turns pressurised fuel into combustion: an electrically fired solenoid valve inside the injector lifts, fuel flows through the nozzle as a metered spray, and the valve closes to end the pulse. Because metering happens inside each injector rather than at a shared pump, small differences between injectors become visible as rough running, which is why injectors carry trim codes and why a full set behaves better than a mixed one.

The naming is where most ordering mistakes start. The words fuel injector, diesel injector and common rail diesel injector describe a function shared by thousands of parts, not one unit. Within the CRIN2 generation, the series behind this listing, the same hardware family serves many engines with different numbers, and neighbouring numbers do not substitute for one another. What makes a unit the diesel fuel injector for your machine is the combination of number, engine plate and code — which is why this page anchors on 0445120538 and treats everything else as reference rather than promise.

On a Mercedes-Benz Actros the diesel fuel injection circuit is one shared path: one pump, one rail, and one injector per cylinder drawing from the same fuel. That is what a common rail injection system means in practice — pressure is held centrally and each injector meters what its own cylinder is told to take — and it explains the split you can diagnose with: a supply-side fault drags every cylinder down together, while a single failing injector shows up on one cylinder and leaves the rest steady.

When an injector stops behaving, the engine tells you through one cylinder before it tells you through the whole high pressure common rail circuit. A rough idle that no filter change cures. Smoke on cold starts that clears late. A fuel injection pulse that arrives late shows up as a knock under load. Each of these is examined properly in the symptoms section below, together with the leak-off test that finds the guilty cylinder without guesswork.

Where our supply differs is what arrives. Bosch and the engine maker supply this part through their own channels, and a buyer who needs a dealer box does need to go there. What we supply is a common rail injector replacement — a new compatible unit for the same job, sold under the Vidishi Auto brand, etched with the same number and code format, at a two-piece minimum with no core return. That last point matters on a diesel job: nothing has to come back, there is no exchange loop to manage, and the old injector stays with you for the parts shelf or the warranty file.

One thing we do not do is dress that up. The 0445120538 injector we ship is ours, not Bosch’s and not Mercedes-Benz’s. The Bosch number and the cross-listed Bosch number appear on this page so you can match the part you are replacing. They are references for fitment, not a claim about who made the part. The Bosch reference pages on this site hold the cross-reference material, and the glossary explains the terminology if any of the names above are unfamiliar.

How we label data. Confirmed means a value read directly from the goods we handle, including the valve-cap printing, the actuator plate and the transport packaging. Reference means a Bosch or Mercedes-Benz number, or a cross-listed aftermarket number, quoted so your paperwork can be matched, and carrying no claim about origin. Not published means the field is left blank on purpose — a flow figure or a component number that we cannot source would be worse than an empty cell, because it would end up in somebody’s parts order.

What is in the box. One complete injector assembly: the injector body with its solenoid valve and nozzle, the fitted seals as photographed, and its own transport tray and carton. Mounting hardware belongs to the engine rather than the injector, and no separate seal kit is asserted for this line. Nothing on this page is sold loose from the injector, and nozzle and valve components keep their own pages for buyers who need those parts individually.

Read the table from the top. 0445120538 is the Bosch number and it is the one that matters on the part itself: it is what the supplied units carry etched on the hex beside the code, and it is the number the reseller catalogues list first. The grouped form, 0 445 120 538, is the same number with the spacing the printed catalogues use, and a parts system will match one form and not the other, which is worth knowing before a search box tells you a part does not exist. As an 0445120538 cross reference, the table is a boundary as much as a bridge.

The rest of the table is the second half of the mapping. 0445120296 is the number this unit is cross-listed with: two independent aftermarket catalogues treat the two numbers as one and the same injector, and the actuator plate on supplied stock is etched with it. That is why the crossed number is shown here rather than hidden — on this generation of injector the plate can carry a Bosch number that differs from the number printed on the carton, and the number to match on is the one etched on the unit coming out of the engine. 4001006200 is the other etch on that plate, recorded exactly as it reads. The Mercedes-Benz cell stays empty on purpose: no source we can stand behind publishes an equipment number for 0445120538, and the family numbers that circulate for neighbouring Bosch numbers belong to those numbers, not to this one.

What the table deliberately does not do is extend itself. It does not say that any other neighbouring Bosch number fits, that a component number for the nozzle or the valve is settled, or that an injector from another engine family substitutes. Those are exactly the assumptions that turn a cheap order into an expensive week of machine downtime, and we would rather leave the cell empty than fill it with a guess. If you are holding a number that is not on this list, send it to us with the engine plate and we will tell you what it is and whether it is this injector.

The practical difference shows up at the leak-off bench. When one cylinder’s injector is returning too much, the machine either runs on a compromised cylinder until something else breaks, or the workshop swaps in a known-good unit and the fault disappears. Keeping a matched spare — correct number, correct code — turns a two-week machine stop into a same-week swap. That is the case for holding these two pieces even before anything has failed, and it is why the minimum order is set where a single repair, not a warehouse, is the unit of purchase.

• Hard startingAn injector that sprays late or weak leaves its cylinder unlit for the first seconds, so the engine cranks longer than it should before it catches.
• Black or grey smoke under loadUnburned fuel leaving the stack as smoke is the classic sign of a spray that has gone coarse, or of a cylinder getting more fuel than it can burn.
• Rough idle, or an idle that huntsAt idle each cylinder counts. One injector metering differently from its neighbours shows up as an idle that will not settle, often with a shake no engine mounting fault explains.
• Loss of power under loadWhen the operator demands fuel, a weak injector cannot deliver its share, and the machine feels flat exactly when it is asked for more.
• High fuel consumptionFuel that leaks past a worn valve inside the injector either returns to the tank or burns badly; either way the fuel gauge moves faster than the work done.
• A misfire that no ignition work curesOn a diesel there are no plugs to swap, and a persistent single-cylinder misfire with clean electrics points at the injector feeding that cylinder.
• Injector leak-off that stands out on the testThe test that settles it. Comparing back-leak volumes cylinder by cylinder shows the injector whose internal sealing has gone, before any part is ordered.

Read the list as symptoms rather than a diagnosis, because every item on it has at least one other possible cause. A tired lift pump or a blocked filter produces the same hard starting. A boost leak produces smoke and flat response without any injector being at fault. Black smoke on a cold start that clears as the engine warms is usually harmless; smoke that stays once the engine is hot and the machine is working is not. What separates them is measurement: back-leak volumes compared cylinder by cylinder with a leak off test, then live data while the engine loads. An injector on its way out shows a injector leak off volume that stands apart from its neighbours; a supply-side fault drags every cylinder down together. A stored rail pressure too low code belongs to the same conversation, and it is worth reading before a part is ordered, because the two causes cost very different amounts.

Two more practical notes. If the machine has recently had fuel system work, look there first: an injector seated dry, an old copper washer reused or a connector not fully latched will produce exactly the symptoms above, and none of them need a new part. And treat one bad injector as a question about the others: they are the same age and they have drunk the same fuel, so a fleet that replaces one usually budgets for the rest. A faulty injector found early is a cheap part; the same injector found late, when its wash has diluted the oil, is an engine discussion.

1. 1. Release the pressure firstLet the engine stand and release residual pressure before anything is opened. A common rail circuit holds pressure after the engine stops, and opening a fitting on a live system sprays fuel at injection-grade force.
2. 2. Clean the well before it is openedWash around the injector, blow the well down, and only then release the clamp. Grit that falls into the open bore ends up on the nozzle seat, and the new injector wears it from its first minute.
3. 3. Lift the old injector squareFree the injector with the correct puller if it resists. Leverage against the wiring or the fuel line ruins parts you are not replacing.
4. 4. Inspect the bore and the seatCheck the copper seat in the head for carbon and scoring. A seat that will not seal is a blow-by path that no new injector will cure.
5. 5. Fit a fresh copper washer and O-ringsA new sealing washer goes under every refitted injector, and every injector o ring on the body is renewed rather than reused. Reused seals are the most common cause of a weep after an otherwise correct diesel injector replacement.
6. 6. Refit square and torque to the engine figureDrop the injector in square, seat the clamp, and torque to the figure for your engine. The figure belongs to the machine, not to the part.
7. 7. Write the trim code before first startProgram the injector trim code — the bracketed code etched on the new injector — into the controller where the engine expects it, so fuel delivery is balanced cylinder to cylinder from the first start.
8. 8. Verify with leak-off and live dataPrime, start, and check idle and load behaviour. Where a doubt remains, the leak-off test confirms the new injector behaves like its neighbours before the machine goes back to work.

Every 0445120538 injector is covered by a 12-month warranty against manufacturing defects. That covers a unit that arrives out of specification or fails early because of how it was made. It does not cover damage from contaminated fuel, from water in the system, from incorrect fitting, from reusing old sealing washers, or from a separate fault elsewhere in the fuel circuit. It is a supplier warranty from Vidishi Auto and it is neither a Bosch warranty nor a Mercedes-Benz warranty — we are not a dealer for either and no cover from either travels with this part.

The cover sits at unit level. It applies to the injector as supplied, and it does not extend to the engine, to the machine, to labour, or to another component damaged when a faulty unit was run on. That boundary is normal for a fuel system part, and it is worth stating before the order rather than after a problem.

Two questions buyers ask. The 0445120538 warranty starts from delivery rather than from fitting, so an injector held on the shelf as a diagnostic spare is still covered for the stated term from the date it reached you. And because there is no core return with our supply, the warranty is not tied to an exchange claim: the old injector stays yours, and what you do with it has no effect on the cover on the new one.

The minimum order quantity is 2 pcs, which is deliberate. Two pieces cover a single machine repair, and they let a workshop keep a known-good injector on the leak-off bench before it commits to anything bigger. From there the line scales normally — a plant fleet running several Actros machines will take a set per engine, and a distributor will take them alongside the rest of a fuel system order on one set of export documents.

We act as a diesel injection specialist supplier for export and we build this line ourselves as the manufacturer behind the Vidishi Auto brand. Injector pricing is quoted per order rather than published as a fixed figure, because pricing moves with quantity and with what else is on the same shipment, which is how fuel injector wholesale normally works. Mixed orders are routine on our side: put these injectors alongside filters, seals or other engine lines and they travel on the same paperwork.

For trade buyers, two practical points about an injector line. First, because there is no core return and no core charge, procurement does not carry a returns loop on top of the order itself — the part of buying fuel system parts that usually costs the most administration simply disappears. Second, batch consistency matters to resale: our batches ship from one production run with uniform etchings, so your stock photographs and your counter claims stay honest. If you need the number matched against a machine list before you commit, send the list with the engine plates and we will work through it with you rather than asking you to take the fitment on trust. Buyers comparing an aftermarket fuel injector line against a dealer box are welcome to ask for the batch photographs before ordering, and construction machinery parts distributors can ask for mixed-batch consolidation across several engine lines on the same shipment.

Batch photographs are part of the offer rather than a favour. What leaves our floor is one production run with uniform etchings, and the picture below shows a batch lined up exactly as it is counted before packing — the same number, the same code format, the same finish on every unit in the row. A distributor who sells against a photograph can only do that honestly if the stock really does look like the photograph.

Distributors serving plant fleets will also find this line sits cleanly beside the wider injector range on this site, and the commercial mechanics of an ongoing account — price reviews, mixed containers, document handling — are described on the partner page. A parts distributor holding this number against an enquiry can quote from this page without waiting for us, and every unit that ships carries the same etchings shown in the photographs above.

The dimensions above are the packed export figures for a single injector in its own carton. We do not list a bare part size or a bare part weight, because no source we can trust gives one for this injector, and a specification table padded with approximations helps nobody. Lead time is quoted per order and depends on quantity and on what else is on the same shipment. For export shipping of fuel system parts, every order leaves with its paperwork in place — commercial invoice, packing list and HS code. Read our shipping information for freight options, and track your order once it ships.

A trade order is packed the way the two photographs show it: units tray-packed in bulk, then grouped into dispatch sets per line so a mixed container can be broken down at the receiving end without a recount. Nozzle tips and valve ends are protected individually before the tray closes, because a damaged tip is the one packaging failure that costs a whole injector rather than a box. If your receiving process needs a different pack — labelled per engine, split per machine or boxed for retail — say so at quote stage and we pack to it.

Where a shipment is consolidated with other engine lines, the dispatch sets are the unit of account: each set carries its own count and its own label, so the paperwork at the destination matches what is actually on the pallet. That is the part of fuel system exporting that generates the most disputes when it is done loosely, and it is worth agreeing before the order rather than after it.

An injector is a small part with a disproportionate effect on how an engine runs, so this line is checked at unit level rather than by sample. Every batch passes an incoming check for the injector number and the bracketed code on the hex, an inspection of the nozzle tip and the valve end, a confirm that the sealing surfaces are clean and undamaged, and a packed-weight confirmation against the documented figure. The supplier states ISO 9001 production, which appears on the supplied photography and is recorded here as a supplier statement rather than as a certificate we issue. Rather than publish reviews we cannot verify, we tell you how the part is inspected and let your own leak-off bench be the judge.

Support is not an add-on on this line — it is how most of these orders get placed correctly. It costs nothing before you buy: send the number read off the injector you are removing, the machine details and a photograph of the engine plate, and we check the whole set against what we supply before quoting. That last item is the one people skip, and it is the one that matters most here, because engine families run several injector numbers across years and ratings. Support continues after delivery: coding questions, fitting questions and warranty claims all reach the same team, and the person who confirmed your fitment is the person who answers if something is not right.

Supplier note. WholesaleAutoPartsDirect is an independent supplier of compatible automotive parts and is not affiliated with, endorsed by or acting as an agent of Bosch or of Mercedes-Benz. Brand names and part numbers are used for reference and fitment only.