Engine Mercedes OM314

Engine Mercedes OM314

OM314 – Diesel engine manufactured by Mercedes-Benz, four-stroke, volume – 3780 cubic centimeters, which corresponds to 345 cubic inches. It is one of the 300 series of engines that began production shortly after World War II. Specifically, OM 314 saw the light of day in 1964, simultaneously with the 6-cylinder analogue of OM 352 and replaced the predecessor OM 301, which produced 55 hp on 6 cylinders.

Agricultural machinery needed a more powerful engine than the 6-cylinder OM301 available at that time. Therefore, the designers prepared 2 power units to replace, one of which was OM314. The new inline 4-cylinder 8-valve engine had 68 hp.

There were two models of 314 engines (OM314 and OM314A). OM314 is used in combine harvesters. The designation “A” indicates the turbo version of the engine.


Engine’s type diesel
Also called OM 314
Production years 1964
End of release 1989
Power output, hp / kW 85 / 63 at 2800 rpm (for OM 314.948)
Displacement, l 3780
Number of cylinders 4
Valves 8
Torque output, Nm / rpm 1800
Compression ratio (compression) 17.0:1
Cylinder bore, mm 97
Piston stroke, mm 128
Crankshaft bearings 5
Configuration inline
Fuel type diesel
Fuel system inline injection pump
Cylinder head OHV
Timing mechanism spur gear
Timing rocker arm
Cooling water

In the domestic open spaces, the motor can also be found on tractors and combines. Most of the agro-industrial enterprises specially changed the motors on their equipment for the 314 engine. It is extremely difficult to buy this unit because of its technical parameters, which allow installation on any truck or agricultural equipment, which makes the 314 incredibly popular.

Frequent problems

All motors produced by Mercedes cannot be overhauled due to the complex architecture and the need to use special equipment. But, given their resource of 500-600 thousand km, after such a run, the power unit can be replaced.

One of the most common complaints about the OM314 is the wear of the timing gears. This problem can only arise if the owner does not properly control the oil and coolant level, and also does not replace some parts in time. There may also be a problem with the adjustment of the valves.

6 thoughts on “Engine Mercedes OM314”

  1. My OM314 has a tacho output from a small dynamo type generator. Does anybody know what output it is supposed to be and how I might convert it into a pulse signal for a common tachometer.

  2. Does anyone know the output from the taco generator. Looks like a miniature dynamo with 2 output wires. How can I convert the signal to one accepted by a common tachometer. IE pulse output.

  3. Frank mccarthy

    I have an OM314 in my boat and in the 26 years I have owned it never once failed to start. I do maintain everything myself. Oil filters, belts etc. I cannot speak too highly of this engine. The engine is 42 years old.

    1. me too, best engine ever on my boat 4000 hours but when the engine is hot the starter blocks from time to time, due to engine room temperatures I guess, and that is not good Peter

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