3-cylinder diesel Engine 3tnv70 10kW Motor diesel 3tnv70-ssy Engine Assembly

Product Overview

A complete power unit, ready to fit. This is a new three-cylinder diesel engine assembly rated at 10 kW, built for machines that run the Yanmar 3TNV70 engine. It arrives as a finished unit rather than a bare block or a box of parts, so a workshop can pull a worn engine out and fit this one in instead of spending days building a short block back up.

The three-cylinder layout and 10 kW output put this small diesel engine in the compact class — machines where a four-cylinder block simply will not fit inside the frame.

Repair shops buy it for the machine with a cracked block, a scored crank, or a head that has been off one time too many. Dealers and fleets buy it because one reference covers a run of small machines, with the filters, hoses and mounts that go with it from the same source. Buyers comparing diesel engine manufacturers for a unit this size are usually weighing a new factory engine against a new aftermarket assembly; this one is in the second group, and it comes with an outgoing inspection video and a machinery test report for the unit you receive.

Have the number off the engine plate in front of you before you order. Two units that look identical from the outside can carry different suffixes, and the suffix is what decides whether the mounts, the injection set-up and the pipework line up with your machine.

Specifications

Engine Model & Fitment

• Read the plate, not the decal. The number stamped on the engine identifies the build. The machine model alone is not enough, because the same excavator engine was offered in more than one version over the production run.
• The suffix is part of the model. The base number and the letters after it are two separate pieces of information; two engines that look alike from the outside can differ in mounting, governor and injection set-up.
• Four photographs settle most questions. The exhaust side, the injection pump side, the mounting feet, and the bell housing face at the flywheel end. Add a clear shot of the engine plate itself.
• Check the machine's electrical system. Whether it runs 12 V or 24 V, and how the alternator, starter and stop solenoid are wired, decides whether the new unit drops straight in or needs the loom adapted.
• Know what comes off the old engine. Exhaust outlet, air cleaner, radiator hoses and any machine-specific brackets may need to be swapped over. Photograph them while the old unit is still in the frame.
• A neighbouring model is a different engine. If the plate reads 3TNV74, 3TNV80, 3TNV82 or a 4TNV unit, say so when you enquire — those are different assemblies with different footprints and are quoted separately. A diesel engine parts supplier who quotes from the machine model alone is guessing; the number on the engine is what counts.

Assembly Contents & Dressing

Dressed, not bare. The unit is supplied as a complete engine assembly, not a short block and not a kit of parts. The photographs show the cast block and cylinder head, the pipework and hoses running along the side, and the front pulley and belt drive already in place.

What the engine does not carry is the equipment around it. Radiator, exhaust system, air cleaner, battery and the machine-side wiring stay with the machine — these are the excavator engine parts that travel with the machine rather than with the new unit. On some installations the fan, the alternator or a bracket is machine-specific, and those come off the old engine and go onto the new one. Photographs taken before removal are the quickest way to see what has to be transferred.

If you need the engine supplied with a particular fitting — a different exhaust outlet, a bracket, a pulley — describe it before the order is placed. Those choices are settled when the build is picked, not after the unit ships. Mounting hardware, fluids and filters are not part of the engine package, so plan them as a separate line and the machine will not be waiting on a filter when the engine lands.

Applications & Machine Types

• Compact excavators. The classic home for this engine: utility, landscaping and trenching machines with a short engine bay and a modest hydraulic load. When an excavator engine gets tired, the first signs are usually hard starting and a lazy response under load rather than a sudden stop.
• Skid steers and small wheel loaders. Yards, farms and small building sites. A small diesel engine of this size keeps the frame short and the fuel draw low on machines that work in bursts rather than all day.
• Orchard, greenhouse and utility tractors. A mini diesel engine suits the narrow frames that work between rows, where the 10 kW rating matches the light implements these machines carry.
• Plant hire and rental fleets. One reference across a run of similar machines keeps a mixed fleet serviceable without holding a different short block for every model on the books.
• Workshop repower jobs. When a machine arrives with a seized or missing engine and the owner wants it earning again rather than restored, a complete unit is usually the shortest route.
• Site dumpers and compact contractors' plant. Small earthmoving equipment built around a three-cylinder engine from any of the diesel engine manufacturers gets the same benefit from a short, narrow package that bolts to the existing mounts.

Installation & First Start

1. Compare before you remove. Put the new unit beside the old one and check the mounting feet, the bell housing face, the exhaust outlet and the injection pump position before anything is unbolted. It is far easier to raise a question at this stage than after the swap.
2. Lift on the points provided. A mini diesel engine of this size still needs a proper sling and spreader rather than a chain run around the manifolds. Take the weight on the lifting eyes and keep hands clear as it goes into the frame.
3. Fit the mounts and check alignment. Sit the engine on its rubber mounts, bring the bell housing up to the transmission and check that the faces meet squarely. Do not pull the two together with the bolts; if the faces are not parallel, the mounts or the adaptor plate are wrong.
4. Connect the machine side. Fuel feed and return, coolant hoses, exhaust, throttle and stop control, alternator and starter wiring. Check the earth strap — a poor earth causes more starting faults on a fresh engine than anything else.
5. Fill and prime. Correct oil to the level on the dipstick, coolant mixed for the conditions the machine works in, and the fuel system bled through to the injection pump before you crank it. Cranking a dry pump does it no favours.
6. First start. Let it idle, watch for fuel, oil and coolant leaks, and check that oil pressure comes up quickly. Bring it to temperature, shut down, let it cool, then recheck the levels and the mount bolts before the machine goes back to work.

Service Parts & Maintenance

• Filters first. Oil, fuel and air filters decide how long a fresh engine lasts. Order them with the engine and match the numbers to the engine plate rather than to the machine model.
• Belts and hoses. A spare fan belt and a set of coolant hoses cost little and remove the most common reason a machine stops mid-week.
• Match excavator engine parts to the build, not to the machine. The same machine was supplied with more than one engine over its life, so a filter listed for the machine may not be the one that fits the engine now sitting in it.
• Oil and coolant to the engine's own specification. Use the grade the engine manual calls for, and mix coolant for the temperatures the machine actually works in — a cold-store machine and a quarry machine in one fleet do not need the same mix.
• Weekly checks. Belt tension, hose condition, oil and coolant levels, and a look underneath for fresh drips. Most trouble on an excavator engine starts as a small leak or a slack belt long before it stops the machine.
• Keep the paperwork with the machine. The test report and the engine number belong in the service file; they make the next filter order and any later warranty question much simpler.
• Wear items are bolt-on. Diesel engine components that wear — injectors, water pumps, starters — are usually available as separate items, so a repair later does not mean replacing the whole engine.

Ordering, Packing & Delivery

1. Send the numbers first. The model and suffix from the engine plate, the machine model and serial, and a photograph of each side of the old unit. As a diesel engine parts supplier we confirm the build against those before a quotation goes out.
2. Confirm the price for your build. This engine assembly is listed at $2,750 per piece and is sold as a single item. The build you need may differ from the build in the photographs, so the price is confirmed against the number you send.
3. Confirm stock and lead time. Some builds are held and others are scheduled. Production and delivery generally run 30 to 60 days depending on the model, so ask for the date that applies to your order rather than assuming.
4. Confirm the packing. The engine ships as one package measuring 65 × 35 × 45 cm at 70 kg gross. If you need a specific packing method — extra bracing, a crate, your own labelling — say so at order and it goes into the packing instruction.
5. Confirm the delivery term. We work on FOB, CFR, EXW, FAS, FCA, CPT, DDP, DDU, DAF and DES terms; tell us which one your forwarder needs and it is written into the quotation.
6. Confirm payment. Most orders are settled by T/T, usually with a deposit at order and the balance against the bill of lading; L/C can also be discussed. We invoice in USD, EUR, CAD, AUD, GBP or CNY.
7. Ask for the documents. The outgoing inspection video, the machinery test report, a specification sheet, the current parts catalog and the written warranty terms for your order all come from your sales contact.
8. Check your market requirements. The listing carries a California Proposition 65 consumer warning. If your market needs that statement, or any other document, raise it before the engine ships.
9. Where it ships. We export to Asia, Europe, Africa, the Americas and Oceania.

Related Yanmar Engine Options

No-Start Diagnostic Checks

1. Start with the stop circuit. On a mechanical engine, the most common reason a healthy unit cranks and never fires is that fuel is still being held off. Check that the stop solenoid or shut-off lever releases fully with the key on, that it receives voltage in the start position, and that its earth is clean and bare metal to bare metal. If the lever stays in the stop position, the engine will crank all day and never catch.
2. Prove fuel reaches the pump. Open the bleed screw at the filter head and work the hand primer, then open the bleed screw on the injection pump body until the fuel runs free of bubbles. Air gets in when a filter is changed, when the tank has run dry, or when a suction line is loose, and a three-cylinder unit of this size will not clear it by cranking alone.
3. Rule out a blocked supply. A filter fitted the wrong way round, a collapsed suction hose, a closed tank valve or a strainer full of debris will pass enough fuel to fill the line and none to run the engine. Check flow at the pump inlet rather than assuming the tank is feeding it.
4. Check the air side. A filter element still in its packing, a rag left in the inlet, or a hose collapsing under suction will stop a fresh engine as effectively as a fuel fault. On a first start after installation this is one of the quickest checks and one of the most often missed.
5. Watch the cranking speed. A small diesel engine has to spin fast enough to build compression heat. If the crank sounds lazy, measure battery voltage at the terminals and at the starter while cranking, then check the earth strap between engine and frame. A new engine with a tired battery and a painted mounting face behaves exactly like a fuel fault.
6. Read the exhaust while it cranks. No smoke at all supports no fuel being delivered. White or grey smoke supports fuel arriving but not burning, which shifts the question to cold-start assist, compression or injection timing. That one observation narrows the fault further than any other check on this list.
7. Leave the pump alone. If fuel reaches the pump inlet and the exhaust stays dry, the fault sits inside the injection pump or the injectors. These diesel engine components need a bench test and a specialist; opening the pump in the yard usually costs more than the repair.
8. Call us with four facts. Have the engine number from the plate, a description of what the exhaust does while cranking, the cranking voltage, and whether fuel is present at the pump inlet — plus a short video of the start attempt. With those we can tell whether the build is wrong for the machine or whether the fault sits on the machine side, such as an interlock, a seat switch or a machine wiring fault that is holding the stop circuit closed.

Technical Support & Model Matching

Choosing the right reference is where most orders succeed or fail, so our team works with you before you commit: send the equipment details and the numbers you already have, and we will cross-check them against the options our supplier network holds, confirm the details that decide fitment, and suggest an alternative when a number has been replaced. After delivery we stay reachable by email, phone and video for installation questions and fault-finding. Founded in 2008 and based in Guangzhou, we export to Asia, Europe, Africa, the Americas and Oceania.

FAQ