Volvo Penta Diesels

In Grampians

Volvo Penta is the most common diesel in our Owners Registry: 31 boats list one, including 15 Grampian 28s, 8 Grampian 30s, 3 Grampian 2-34s, 2 Grampian 26s, 2 Grampian 34s, and a Discovery 7.9 (November 2026). The models owners name are the MD6A, MD7A (two with a saildrive), MD2B, MD11C, 2002B, and MD2030B.

• Grampian 28: it came with an Atomic 4 or a Volvo diesel. A 1975 Grampian 28 has been sold with its MD6A, and the MD7A, built from 1976, would fit later boats. The saildrive the registry lists as "9.6 hp" is very likely an MD7A, which Volvo rated at 9.6 kW.
• Grampian 26: in the early 1970s, a Volvo MD1B diesel was a factory option (Practical Sailor gives its price as $2,100, against $1,800 for an Atomic 4). Most 26s had outboards, and later inboards were often 8 hp Yanmars.
• Grampian 30 and 2-34: the MD2B and MD11C fit the years these boats were built, as factory engines or early replacements.
• Later engines: a 2002B (built 1991 to 1993) or an MD2030 is a replacement, since Grampian stopped building in 1977.

Read the plate on your engine for its model and serial number: you'll need them for parts, manuals, and Volvo's parts diagrams. Please add the model to your registry entry.

The models

• Cooling: the MD-series engines are raw-water cooled: lake or sea water runs straight through them. Most 2000-series engines are too, though fresh-water versions exist. The MD2000 series is fresh-water cooled, with a heat exchanger and antifreeze in the engine.
• Starting: the MD1B, MD2B, and MD6A have a combined starter and generator, slow to crank and weak at charging. The MD7A has a separate starter, and can be started by hand using its decompression handle.
• The MS gearbox uses Volvo's cone clutch: a cone that's pressed into the forward or reverse gear.
• The MD11C shares the MD2B's cylinder size (88.9 × 90 mm) and replaced it.

Figures are from Volvo Penta's instruction books and workshop manuals, with parts specialists' figures where those are missing. Sources differ slightly on some ratings and years.

Saildrives

A saildrive takes the drive straight down through the bottom of the hull to a propeller on a leg, with no propeller shaft. Volvo's 110S came with the MD7A and MD11C from about 1976, and the 120S with later engines. The leg is sealed to the hull with a large rubber seal, which matters a great deal:

• Replace the hull seal on schedule. Volvo's own schedule for the MD2000 series says to check it every year and replace it every seven years; Yachting Monthly gives it 5 to 10 years. It's usually a dealer job, with the boat hauled out. Ask a seller when it was last done, and for the invoice.
• Watch for corrosion. The leg is aluminium and corrodes fast with the wrong anodes, antifouling, or wiring. Use copper-free antifouling on it, replace the anodes when they're half worn, and keep it electrically isolated as Volvo specifies.
• Milky oil in the leg means water is getting in.
• The 110S drives through a rubber flange; check it when the engine is serviced.

The drive coupling and shaft

On a boat with a propeller shaft, the engine's gearbox drives the shaft through a coupling: two flanges bolted face to face, one on the gearbox and one on the shaft. Measure the shaft and the flange before ordering a coupling or fitting a different engine, and have the alignment checked whenever the engine or its mounts are changed. Engine mounts sag after 15 to 20 years, throwing the alignment off and causing vibration.

Buying a used one

• Read the plate (model and serial number) and compare it with the years above, to know what you're buying and whether parts are still made.
• Start it cold, and by hand where it's made to be. It should start promptly without a lot of smoke.
• Check the cooling: a strong flow of water at the exhaust, and no overheating when it's worked hard under way.
• Look for corrosion on the exhaust elbow and the cylinder head, especially on a raw-water engine from salt water.
• Check the oil in the engine, gearbox, and saildrive: milky oil means water is getting in.
• Shift into forward and reverse: the gear should engage cleanly, without slipping.
• On a saildrive, ask when the hull seal was last replaced, and look at the anodes and the leg.
• Check the mounts and alignment.

Care and common problems

• Raw-water cooling: the MD-series engines were built to be simple and inexpensive, and in salt water their cooling passages eventually scale up and corrode; owners report badly corroded MD7A heads. Engines that have spent their lives in fresh water usually fare better. Volvo's MD7A book lists the causes of overheating: a blocked intake, a worn impeller or pump, the thermostat, or the temperature sender.
• The impeller: check it every year or 200 hours, and carry a spare. Even an unused impeller can fail after years on the shelf.
• The exhaust (mixing) elbow, where cooling water joins the exhaust, is known for clogging with carbon, which causes overheating. Inspect it every few years.
• Fresh-water engines (MD2000 series): clean the heat exchanger every 400 hours or two years, and change the coolant every other year.
• The gearbox: change the gear oil every 200 hours. If the cone clutch slips, check the adjustment of the shift cable first; owners find a misadjusted cable is a common cause, and it wears the cone.
• Injectors: have them pressure-tested every 400 hours or two years.
• The MD2B: owners warn that a failed O-ring in the oil pump can starve the bearings of oil.

Replacing an old Volvo

Volvo Penta sells repowering kits that put a modern D1 or D2 diesel in place of an MD1, MD2, MD5, MD6, MD7, MD11, 2001–2003, or MD2010–2040, with brackets made to fit the old engine bed. The old reverse gear has to be replaced too. A 110S saildrive must be replaced, while a 120S can stay, with its own kit. See Volvo's D1/D2 repowering kit leaflet (PDF).

Manuals

Free to read on ManualsLib, from Volvo Penta's own books:

• MD1B, MD2B, and MD3B instruction book and workshop manual
• MD6A instruction book and the MD6A and MD7A workshop manual
• MD7A and MD7A/110S instruction book
• MD11C, MD17C, and 110S instruction book
• 2001, 2002, and 2003 operator's manual and workshop manual
• MS2 gearbox and 120S saildrive workshop manual
• MD2010 to MD2040 operator's manual and workshop manual

From Volvo Penta: manuals and support, where some owner's manuals can be downloaded and workshop manuals bought, and parts diagrams you can look up by serial number.

Parts and help

• Volvo Penta: look up parts by your engine's serial number, and find a dealer with the dealer locator (Canada and the US included).
• Older engines: many MD-series parts are no longer made by Volvo, and owners report that MD7A cylinder heads are among them. What's left, especially for the gearbox, can be expensive; owners also find parts through dealers' old stock and engines being parted out.
• Aftermarket parts: UK specialists ASAP Supplies (pages for each model), parts4engines, and Poseidon Marine, and Finland's Marineparts.fi. These aren't genuine Volvo parts.
• Forums: owners of these engines share a lot on the UK's YBW forum, SailboatOwners.com, and Old Marine Engine.
• Reading: 48° North on cooling systems, Practical Boat Owner on overheating, and on saildrives, Yachting Monthly and Cruising World.
• Fellow Grampian owners: ask in the registry, and see our Engine FAQ.

Sources

• Volvo Penta instruction books and workshop manuals (above), and its repowering leaflet
• Model years: ASAP Supplies model pages
• Grampians: Practical Sailor on the Grampian 26, Wikipedia: Grampian 28, a 1975 Grampian 28 with its MD6A, and Cruising World on the Grampian 30
• Care: 48° North, Practical Boat Owner, Yachting Monthly, Cruising World, Murray Yacht Sales on the MD2030, and owners on YBW (MD2B) and YBW (MD7A)