Volvo Penta · Inboard diesel

Volvo Penta MD11C

The MD11C (two cylinders, 1.12 litres) and the MD17C (three cylinders, 1.68 litres) are direct-injection auxiliary diesels with direct raw-water cooling that Volvo Penta sold for sailing yachts from the late 1970s, rated 23 and 35 hp at 2500 rpm; Volvo presented them as developments of the MD2B and MD3B. They came with the MS-B reverse gear or the 100S/110S saildrive, and also as HD (heavy duty) and HY (hydraulic drive) versions. The later MD11D and MD17D of Volvo’s “3000 series” give 25 and 36 hp at 3000 rpm with the MS2 reverse gear or the 120S saildrive. This page covers all four: filters, thermostat, injectors and gaskets are shared, while the sea-water pump, impeller and V-belt differ between MD11 and MD17.

Manuals & documents
Wear parts & part numbers
Service intervals
Specifications
Good to know
Fitted in
On the marketplace

Manuals & documents

The links go straight to Volvo Penta. We host no manuals or drawings — the manufacturer’s copy is the current one.

Instruction book MD11C, MD11C/110S, MD17C, MD17C/110S Operation manual pubs.volvopenta.com · PDF · EN
Instruction book 3000 series: MD11D, MD17D with MS2 or 120S Operation manual pubs.volvopenta.com · PDF · EN · DE · FR · ES · IT · SV
Workshop manual MD11C, MD11D, MD17C, MD17D (printed copy to order) Service manual volvopenta.mis.elanders.com · EN
Volvo Penta manuals & handbooks: MD11C Manual portal volvopenta.com · EN
Volvo Penta manuals & handbooks: MD11D Manual portal volvopenta.com · EN
Volvo Penta manuals & handbooks: MD17C Manual portal volvopenta.com · EN
Volvo Penta manuals & handbooks: MD17D Manual portal volvopenta.com · EN
Volvo Penta parts catalogue, filtered to MD11C Parts catalogue volvopenta.com · EN
Volvo Penta parts catalogue, filtered to MD17C Parts catalogue volvopenta.com · EN
Parts catalogue: MD11C cooling system, sea-water pump, thermostat and exhaust Parts catalogue volvopenta.com · EN
Parts catalogue: MD17C cooling system, sea-water pump, thermostat and exhaust Parts catalogue volvopenta.com · EN
Parts catalogue: gasket sets, bearing and piston kits MD11/MD17 Parts catalogue volvopenta.com · EN
Parts catalogue: repowering kit MD11C/D to D1-13/20/30 and D2-40 Parts catalogue volvopenta.com · EN
Product bulletin MD11C (standard equipment, MS-B gear) Product leaflet pubs.volvopenta.com · PDF · EN
Product bulletin MD17C Product leaflet pubs.volvopenta.com · PDF · EN
Product bulletin MD11C/110S Product leaflet pubs.volvopenta.com · PDF · EN
Product bulletin MD17C/110S Product leaflet pubs.volvopenta.com · PDF · EN
Product bulletin MD11D HD-HE (heavy duty, heat exchanger) Product leaflet pubs.volvopenta.com · PDF · EN
Brochure “Auxiliary engines for sailing boats 7.5–89 hp” (MD11C, MD17C, 110S) Brochure pubs.volvopenta.com · PDF · EN
Brochure “Diesel engines and transmissions” (3000 series: MD11D, MD17D with MS2 or 120S) Brochure pubs.volvopenta.com · PDF · EN

Wear parts & part numbers

Part	OEM number	Also fits	Note
Impeller kit (with gasket)	`21951342`^1,2,3,4,5replaces 3586496	—	MD11C and MD11D with the small pump 858065: impeller and cover gasket 833994, cover held by four screws. Six vanes, about 39.5 mm across, 19 mm wide, 12 mm shaft. The original on-board kit held 875583.
Impeller kit (with gasket)	`22222936`^6,7,8,9,10replaces 3593659	—	MD17C and MD17D, and freshwater-cooled MD11 versions (spec 867600/-684), with the larger pump 829895: impeller, cover gasket 840385 and lubricant; cover held by six screws. The original MD17C on-board kit held 875808.
Pump cover gasket	`833994` · `840385`^1,6,11,12	—	833994 for pump 858065 (MD11C/D), 840385 for pump 829895 (MD17C/D). Both come with the impeller kits.
Raw water pump	`858065`^1,2,3,13replaces 833522replaces 833883replaces 840076	—	MD11C and MD11D with direct raw-water cooling.
Raw water pump	`829895`^6,14,7,9,15replaces 825916replaces 829650	—	MD17C and MD17D, also freshwater-cooled MD11 versions. Repair kit for this pump: 875698.
Engine oil filter	`834337`^16,17,18	—	Spin-on filter, the same on MD11C, MD11D, MD17C and MD17D. The original lubrication diagrams still show the earlier number 897321.
Fuel filter (engine)	`829913` · `870065`^{19,20,21,22,23}	—	829913: spin-on element for filter heads 829912/840532 (MD11C from engine no. 50884, MD17C from 16372, all MD11D and MD17D). 870065: insert for the Bosch bowl filter (housing 803323) of earlier engines, held by a centre bolt.
Fuel pre-filter	`829666`²⁴	—	Insert for the optional Volvo Penta water separator 833971, only if one is fitted.
Fuel lift pump	`833323` · `834255`^25,26	—	833323 is the diaphragm feed pump with hand primer, the same on all four engines; 834255 is its repair kit (diaphragm, strainer, gaskets).
Alternator V-belt	`958306` · `960283` · `958317` · `958320`^{27,28,29,30,31,32,33}	—	MD11C 958306 (900 mm, the belt in on-board kit 875643), MD11D 960283 (913 mm), MD17C 958317 (1175 mm), MD17D 958320 (1250 mm). Some later MD11C specs take 958322 (1300 mm) or 958326 (1400 mm), freshwater and HD versions 958332 (1550 mm) or 958330 (1500 mm). Measure the old belt.
Thermostat	`876080`^3,7,9,34	—	Kit for raw-water-cooled engines (62 °C, late type). Freshwater-cooled versions: 877349 (74 °C, spec 867600/-684) or 838501 (76 °C, MD11C spec 867577).
Thermostat gasket	`416033`^3,26	—	Sealing ring; also part of the gasket sets 875553 and 875572.
Air filter	`833414`^3,7,35	—	Intake silencer with filter, one per cylinder (two on the MD11, three on the MD17). It is cleaned, not normally replaced.
Fuel injector	`829907` · `833191`^21,22,36,37	—	One per cylinder. 829907 on the MD11C from engine no. 50989, the MD17C from 16622 and all MD11D/MD17D; earlier engines have 833191.
Injector nozzle	`829909`^21,22,36,37	—	For injector 829907.
Exhaust mixing elbow	`833585` · `833586`^3,7,38,39	—	833585 riser on the MD11, 833586 elbow on the MD17. Specs 867498/867499 from engine no. 49895 have the water-cooled bend 833583 (gasket 800326); heavy-duty versions 833998.
Exhaust elbow gasket	`859015`^3,40replaces 803374	—	Exhaust flange gasket, listed for the MD11C.
Cylinder head gasket	`833453`^26,15	—	One per cylinder: two on the MD11, three on the MD17. Also in the gasket sets.
Gasket set	`875553` · `875572`^26,15	—	Decarbonising (top-end) sets: 875553 for the MD11C/D, 875572 for the MD17C/D. Complete reconditioning sets: 875554 (MD11) and 875573 (MD17).
Ring anode	`833913` · `833915` · `828140`^41,42	—	Zinc anode on the propeller shaft (shaft-line installations): 833913 for 25 and 30 mm shafts, 833915 for 35 mm, 828140 for 40/45 mm.
Saildrive anode	`875812` · `876603` · `851983`^43,44,45	—	110S drive: zinc 875812 for salt water, magnesium 876603 for fresh water. The 120S drive on the MD11D/MD17D takes zinc anode 851983.

Numbers checked against the sources below on 12 October 2026. Always confirm against your serial number and exact type before ordering.

Service intervals

Task	Interval
Oil level check	Daily, before starting⁴⁶
Engine oil change	Every 50 h, first time after 20 h⁴⁶
Oil filter	First at 20 h, then at every second oil change (100 h), at least once a season⁴⁶
Gearbox oil change	Reverse gear: change every 50 h; check the gear oil level every 14 days⁴⁶
V-belt check	Check tension every 14 days (about 5 mm deflection under thumb pressure midway between the pulleys); inspect every 100 h or once a season and replace if worn or cracked⁴⁶
Battery	Check the electrolyte level every 14 days⁴⁶
Raw water impeller	Check the cooling system and impeller every 100 h or once a season; replace the impeller if damaged⁴⁶
Air filter	Clean every 100 h or once a season⁴⁶
Fuel filter	Replace the element and clean the feed pump strainer at least once a season⁴⁶
Valve clearance	Check and adjust every 50 h and after each retightening of the cylinder heads (workshop)⁴⁶
Injectors	Have them cleaned and tested by a diesel workshop once a season⁴⁶
Rubber seal (drive to hull)	120S saildrive (D versions): replace every 5 years⁴⁷

Hours or season, whichever comes first. From Volvo Penta’s instruction book for the MD11C and MD17C; the saildrive seal interval comes from the 3000-series book for the MD11D and MD17D.

Specifications

Cylinders	2 (MD11C, MD11D) or 3 (MD17C, MD17D), in-line; wet replaceable liners, one cylinder head per cylinder⁴⁶
Displacement	1.12 l (MD11C/D), 1.68 l (MD17C/D)⁴⁶
Bore × stroke	88.9 × 90 mm⁴⁶
Power	MD11C 17 kW (23 hp), MD17C 25 kW (35 hp) at 2500 rpm; MD11D 18.4 kW (25 hp), MD17D 26.5 kW (36 hp) at 3000 rpm; at the propeller shaft, DIN continuous rating⁴⁷
Rated speed	2500 rpm (C versions), 3000 rpm (D versions)^46,47
Idle speed	650–780 rpm (C), 750–800 rpm (D)⁴⁷
Cooling	Direct raw-water cooling with thermostat; the pump is driven from the camshaft via a rubber flange. Freshwater cooling with a heat exchanger was an option on some versions.⁴⁶
Engine oil capacity	MD11C/D 2.6 l without filter, 2.9 l with filter; MD17C 4.2/4.5 l; MD17D 4.4/4.7 l (without/with filter)⁴⁷
Engine oil grade	API CD. C instruction book: SAE 20 (multigrade) above +10 °C, SAE 10W below; D book: SAE 15W-40 above +10 °C, SAE 10W below^46,47
Compression pressure	20–24 kp/cm² (144–173 psi) at starter speed⁴⁶
Injection pressure	170–178 kp/cm² (2418–2531 psi); Bosch nozzle holder KBL 87S78/4 with nozzle DLLA 150S720⁴⁶
Injection timing	23–26° BTDC⁴⁶
Injection	Bosch injection pump PRF 2K 75A 407/11 (MD11C) or PRF 3K 75A 408/11 (MD17C); diaphragm feed pump with hand primer, feed pressure 0.75 kp/cm²⁴⁶
Thermostat opens at	MD11C 60 °C (fully open 75 °C); MD17C 57 °C (72 °C); MD11D/MD17D 60 °C (74 °C)^46,47
Alternator	12 V, 35 A (420 W) on the C versions⁴⁶
Starter motor	12 V; 1.5 kW (C versions), 1.1 kW (MD11D), 1.9 kW (MD17D)^46,47
Weight	With reverse gear: MD11C 230 kg, MD17C 290 kg, MD11D 221 kg, MD17D 281 kg. With saildrive: MD11C/110S 247 kg, MD17C/110S 317 kg, MD11D/120S 238 kg, MD17D/120S 308 kg⁴⁷
Gearbox	C versions: MS-B reverse gear (cone clutch) 1.91:1 or 110S saildrive 1.66:1, also 100S and hydraulic HY drives. D versions: MS2 reverse gear 2.4:1 or 3.0:1, or 120S saildrive 2.20:1^46,47
Gearbox oil	Engine oil, same grade as the engine: MS-B 0.6 l, 110S 1.8 l, MS2 0.8 l, 120S 2.2 l^46,47
Tightening torques	C: cylinder head 11.0 kpm (79 lbf ft) on the 19 mm bolts, 4.5 kpm (32 lbf ft) on the 15 mm bolts, injector nuts 2.0 kpm. D: head nuts 110 Nm, injector yoke nuts 20 Nm^46,47
Max. installation angle	15° rearwards and 15° sideways underway⁴⁶
Direction of rotation	Clockwise, seen from the flywheel⁴⁶

Good to know

The MD11 and MD17 have different sea-water pumps. The two-cylinder engines use the small pump 858065 with impeller kit 21951342 and a cover held by four screws; the three-cylinder engines use pump 829895 with kit 22222936 and six cover screws. Freshwater-cooled MD11 versions also have the larger pump, so count the screws before you order.^1,6
On the C engines the impeller is held on the pump shaft by a screw: pull the shaft out slightly to reach it, then hold the shaft while you draw the impeller off. If impeller and shaft turn by hand with the engine stopped, the rubber drive flange behind the pump is worn.⁴⁶
Check which fuel filter you have before buying: early engines have a Bosch bowl filter with a loose insert (870065) held by a centre bolt, later ones the spin-on element 829913. Afterwards bleed the system at the filter’s vent screw with the hand primer; if the primer lever feels dead, turn the engine over a little.^20,46
Each cylinder has its own head and head gasket. After work on the heads, torque the bolts in Volvo’s sequence before the first start and again after 20 hours, check them every 100 hours or once a season, and reset the valve clearance each time: 0.30 mm inlet and 0.35 mm exhaust with the engine hot.⁴⁶
If the boat is afloat but not used, run the engine warm every 14 days. On long passages under sail, the 3000-series book suggests running it for about five minutes every ten hours, with the lever in neutral for a fixed propeller or in reverse for a folding one so it stays folded.^46,47
If the old engine is beyond saving, Volvo Penta sells engine-bed bracket kits that put a D1-13/20/30 or D2-40 into an MD11C/D bed, and a kit for the MD17 to take a D2-55/75 with saildrive.⁴⁸

Fitted in

Boats whose builder lists it as standard or optional equipment:

Tayana 37 — Volvo Penta MD17C (Early years: Ta Yang had stocked the ‘Volvo 17C’ but no longer did by June 1983)
Westerly Centaur — Volvo Penta MD11C 23 hp (Standard in the price lists of February 1977 to September 1980 and recommended in the brochure of December 1977, installed like the MD2B, with a three-blade propeller)

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Sources

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