A parts diagram or exploded view is the fastest way to point at the item you need, and the slowest way to order it — because the number printed next to the position on the drawing is usually not the number you can buy. This guide covers what to read off a drawing, what to ignore, and how to turn it into a reference we can confirm against your engine.
It is a sourcing guide, not a workshop manual. We do not reproduce manufacturer drawings, and we do not publish torque values, clearances, or assembly procedures — those belong to the official documentation for your engine.
Engine systems you will see on a diagram
The map below is drawn by us from our own catalogue, so the counts are the part numbers we actually hold records for — not an illustration. Click any system to browse that group, or use it as a checklist while you work through a drawing. A small number of records sit outside these groups (general engine components, lubrication, intake) and are reachable from the full part-number catalog.
From the drawing to a part number
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1. Find the drawing that matches your engine generation
A parts diagram or exploded view is drawn for one engine generation, not for a series name. Two engines badged "16V 2000" from different production runs can have a different injector, liner, or gasket shown in the same position on the page. Start from the drawing number or the engine designation on your nameplate, not from the model badge alone.
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2. Walk the drawing by system, not by position number
Exploded views are laid out by assembly: cylinder head and valve train at the top, piston and liner in the middle, crankcase and bearings at the bottom, with fuel, cooling, and turbocharging drawn as separate sub-assemblies. Work one sub-assembly at a time and note the position number shown on the drawing.
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3. Read the position number, then look up the reference it points to
The position number on the drawing is an index into that drawing’s parts list — it is not the part number. Read across to the reference the list gives for that position. On MTU drawings this is normally the long numeric reference, and on older documentation it may be a short reference with a slash suffix.
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4. Expect the reference on the drawing to be superseded
Drawings stay in print for decades. The number you read off an old drawing is frequently superseded, and the current supply reference is a different number. This is the single most common reason a buyer orders the wrong item, so the reference should always be checked against the serial number range before it is quoted.
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5. Confirm by engine serial number before ordering
The drawing tells you which position and which family of part. The engine serial number tells you which revision of it your engine actually carries. Send the drawing reference together with the serial number and we confirm the current number, the supply route, and the lead time before anything is ordered.
What to send with a diagram reference
A diagram reference on its own is not enough to quote against, because it does not identify the production revision. Send these and we can confirm the current number instead of quoting the one printed on a drawing that may be older than your engine:
- The reference or position number as it appears on your drawing
- The drawing, parts-book, or engine designation the reference came from
- Engine model as shown on the nameplate, with the full suffix (for example 12V 4000 M93L)
- Engine serial number — this decides which revision of the part fits
- Quantity, and whether the engine is in service or going into an overhaul
- A photo of the old part, including any stamped or cast number
- Destination, so lead time and freight can be quoted with the price
If the reference is unreadable or missing entirely, that is not a dead end — send the photos and the serial number and we identify it from the position and the engine record.
Related reference tools
- Parts Lists by Engine Model — every catalogued part number for your model code, grouped by system
- Part Number Cross Reference — superseded and OEM numbers mapped to the parts we supply
- MTU 4000 Variant Decoder — what the M-duty suffix on the nameplate changes
- MTU Part Number Catalog — all 891 part numbers, searchable
- Catalog PDF Downloads — the same index as a printable, searchable PDF, one file per series
- Dealer or Independent Supplier — which sourcing route suits the engine
- All parts guides — overhaul planning and series identification
FAQ
Can you send me a parts diagram or the workshop manual?
We do not distribute manufacturer drawings or manuals — they are published by the engine maker and supplied under their own terms. What we can do is read the reference you take off your own drawing and tell you the current part number, the interchange options, and the lead time. Send the position number, the drawing or engine designation, and your engine serial number.
I only have a photo of the old part. Is that enough?
Often yes. A clear photo of the part plus the engine model and serial number is usually enough for us to identify the reference, especially where the original number is stamped on the component. Include a second photo of any stamped or cast number on the part, and tell us which position it came from.
Why does the same position show different numbers on different drawings?
Because the drawing belongs to a specific engine generation and configuration. Injection, cooling, and management systems changed across production runs, so a position that carries one reference on an early drawing carries another on a later one. The serial number range decides which applies to your engine.
Do you publish part-number ranges for each system?
No. Part numbers do not follow a range that maps cleanly onto a system — the same prefix appears across unrelated groups, and the suffix decides the exact item. We publish the part numbers we supply, grouped by system and engine series, each verified against engine details before quoting. Use the zone map above to browse by system, then confirm your reference with us.
Send the reference and the serial number: Position number, engine model, and serial number are enough for us to trace the current part number and quote availability.