Volvo Penta MD2020 Rebuild, common faults and everything you need to know
Classic inboard for smaller cruising yachts. 3-cylinder naturally aspirated IDI diesel, cast iron block from Shibaura, gear-driven camshaft. Freshwater cooled via heat exchanger with a raw-water circuit. Built 1993-2002.
The MD2020 is one of the most typical sailboat diesels in harbours everywhere. We most often see it in smaller cruising yachts that have run their 2,000-4,000 operating hours and are starting to show the signs of age: hard cold starting, sooty exhaust, a blocked heat exchanger and a corroded exhaust elbow. The 3-cylinder cast iron block (Shibaura, also badged by Perkins) is robust and takes a full rebuild, but it is the ancillaries - heat exchanger, exhaust elbow, raw-water pump, injectors - that usually decide how much work is needed. We do everything from cylinder head reconditioning, cylinder boring and crankshaft reconditioning to complete engine reconditioning in our own machine shop with 12-month warranty. See also our boat engine rebuild hub page.
MD2020 at a glance
Data taken from Volvo Penta's workshop manual for the MD2010/MD2020/MD2030/MD2040 (publ. 7741986, technical data p.9), cross-verified against three independent research passes.
MD2020 variants A-D
Four generation versions from 1993 to 2002. Power and displacement unchanged across the whole run (a single ~19 hp calibration).
| Variant | Period | Change |
|---|---|---|
| MD2020A | 1993-1994 | Original launch |
| MD2020B | 1994-1998 | Updates to electrical system and accessories |
| MD2020C | 1998-2000 | Detail changes |
| MD2020D | 1998-2002 | Final production version |
Note - the whole series is linked. The MD2020 shares its workshop manual and torque table with the MD2010, MD2030 and MD2040. In the table the MD2010 and MD2020 sit in a shared column, while the MD2030 and MD2040 have their own values for the highly loaded joints (cylinder head, big-end bearings, flywheel, crankshaft pulley, injectors).
Marine-specific components
What sets the MD2020 apart from an industrial Shibaura and must be checked at every major service or reconditioning.
Tightening torque MD2020
All values are taken from Volvo Penta's workshop manual (technical data p.17 and the assembly chapter p.34), the MD2010/MD2020 column, and are image-verified against the actual manual pages. The values apply jointly to the MD2010 and MD2020 and generally differ from the MD2030 and MD2040. Always check against the current manual before assembly.
Cylinder head (3-stage sequence)
| Joint | Operation |
|---|---|
| Head bolts stage 1 | 10 Nm |
| Head bolts stage 2 | 20 Nm |
| Head bolts final torque (stage 3) | 35-40 Nm |
| Rocker pedestal / rocker shaft | 20-25 Nm |
| Valve cover | 10-12 Nm |
Bottom end
| Joint | Operation |
|---|---|
| Main bearing cap to block | 25-30 Nm |
| Big-end bearing | 21-26 Nm |
| Flywheel bolts | 70-80 Nm |
| Crankshaft pulley, centre bolt | 90-100 Nm |
Fuel and other
| Joint | Operation |
|---|---|
| Injector / nozzle holder in cylinder head | 60-70 Nm |
| Delivery pipe (high-pressure pipe) nuts | 20-25 Nm |
| Glow plugs | 15-20 Nm |
| Drain plug, oil pan | 30-40 Nm |
Note identity data, not torque. The MD2020 is published by Volvo Penta with a power output (19 hp at the crankshaft), not with a tabulated torque figure. The curve in the product sheet is a diagram, not a tightening torque - do not confuse the engine's power output with the tightening torques above. The bolt torque for the intake and exhaust manifold, as well as the raw-water pump mounting, are missing as their own rows in the torque table and should be taken from the general bolt table by thread dimension.
Common faults on the MD2020
Cross-verified against the YBW Forum, sailing club owner forums, service bulletins from Volvo Penta workshops and the three research passes behind the engine data above.
Hard cold start - glow plugs and compression
Age-related fault • High- Symptoms
- The engine will not fire in cold weather, needs long preheating, smokes white and coughs before it catches.
- Cause
- The MD2020 has three glow plugs for cold starting. One or more faulty glow plugs, worn IDI injectors or falling compression in the small 0.68-litre engine make cold starting difficult. Compression should be above 3 000 kPa at cranking speed.
Exhaust elbow and exhaust manifold corrode
8-12 seasons • High- Symptoms
- Salt water in the wake, sooty exhaust, salt drips under the engine, in the worst case water in a cylinder.
- Cause
- The raw-water cooled exhaust elbow corrodes from the inside. Perforation can let salt water into the exhaust passage and, if the engine is standing still, lead to a hydraulic lock. The freshwater cooled manifold can also become blocked.
Heat exchanger blocked internally
Recurring • Medium- Symptoms
- Lowered thermostat opening temperature, overheating under load, lower top rpm.
- Cause
- Scale and salt deposits on the raw-water side of the tubular heat exchanger. A lack of anodes speeds up the corrosion.
Raw-water impeller breaks up
Recurring • Medium- Symptoms
- No cooling water flow, overheating within minutes, impeller blades lodging in the heat exchanger.
- Cause
- The rubber impeller cannot take running dry - roughly 15-30 seconds without water is enough for failure. The seating surface in the pump housing wears.
Injector nozzles carbon up
3,000+ hours • Medium- Symptoms
- Rough idle, black smoke under load, dropping top rpm, increased fuel consumption.
- Cause
- Natural wear on the nozzle needles and coking of the diesel residue in the nozzle tip. The nozzle holders are torqued to 60-70 Nm on reassembly.
MD2020 reconditioning prices
Prices based on MD2020 specifications (3 cyl, 67 mm bore, 6 valves, cast iron block and cast iron cylinder head). All prices exclude VAT and parts. All main operations - cylinder boring, crankshaft grinding, cylinder head resurfacing - are carried out in our own machine shop.
Cylinder head reconditioning
Bottom end
Full rebuild
Marine components
Cylinder machining
| Service | Price |
|---|---|
| Cylinder boring 3 cyl (67 mm) | 2 489 kr |
| Plateau honing 3 cyl | 788 kr |
| Cylinder liner replacement 3 cyl | 5 850 kr |
Crankshaft work
| Service | Price |
|---|---|
| Crankshaft grinding 3-cyl (4 main + 3 rod) | 2 710 kr |
| Polishing standard | 1 022 kr |
| Wash 3-cyl crankshaft | 706 kr |
Cylinder head reconditioning
| Service | Price |
|---|---|
| Resurfacing cast iron cylinder head 3 cyl | 1 390 kr |
| Valve cutting 6 valves | 683 kr |
| Valve guide replacement 6 pcs (cast iron) | 1 185 kr |
| Cylinder head pressure testing | 1 876 kr |
See also
Other Volvo Penta marine diesels we service and related services.
Questions and answers about the MD2020
How many cylinders does the MD2020 have?
Three. The MD2020 is a 3-cylinder engine of 0.68 litres according to Volvo Penta's technical data (workshop manual p.9). It is the smaller MD2010 that has two cylinders. A common mix-up is to assume the MD2020 is a 2-cylinder - the data table says three.
What does it cost to recondition a Volvo Penta MD2020?
A cylinder head reconditioning costs SEK 5,500-7,500 in labour. A complete engine reconditioning SEK 24,000-36,000 in labour, plus parts typically SEK 6,000-14,000 depending on condition. Marine components (exhaust elbow, heat exchanger, raw-water pump) often add SEK 4,000-10,000.
Is the MD2020 turbocharged?
No. The MD2020 is a naturally aspirated, indirect injection (IDI) diesel with no turbo. It is a classic small sailboat engine of 19 hp with no boost.
Which block is in the MD2020?
A Shibaura block. The workshop manual's own footnote points to the SHIBAURA marking in the piston. The same base engine was also sold by Perkins (Perama M20 / Perkins 103-07). Volvo Penta marinises and badges the block - so it is not a Volvo in-house design.
What is the cylinder head torque on the MD2020?
The cylinder head is torqued in three stages according to the workshop manual: 10 Nm, then 20 Nm, and finally 35-40 Nm in the prescribed sequence. This value applies jointly to the MD2010 and MD2020. The MD2030 and MD2040 have a higher final torque in their own columns - always use the right column for your model.
How long does an MD2020 last?
5,000-10,000 operating hours with proper maintenance. The 3-cylinder cast iron block is industrial and takes more than that - it is the heat exchanger, exhaust elbow, raw-water pump and glow plugs that typically set the limit. A well-reconditioned MD2020 gives the owner many more seasons.
How long does an MD2020 reconditioning take?
Cylinder head reconditioning: 1-2 weeks. Complete engine reconditioning: 3-5 weeks in the workshop, plus lead time on parts (injectors, heat exchanger, exhaust elbow). The winter season (October-April) is the busiest - book in good time.
Do you have an MD2020 that needs looking over?
Call us or send a quote request. Reply within 24 hours. We service all types of boat engines - see boat engine page. All rebuilds with 12-month warranty.