Mitsubishi 6A12 engine
Content
Invented by the Japanese engine builders of Mitsubishi Motors Corporation (MMC), the 6A12 engine has been repeatedly improved. Despite significant changes, the index remained constant.
Description
The 6A12 power unit was produced from 1992 to 2010. It is a gasoline six-cylinder V-shaped engine with a volume of 2,0 liters and a power of 145-200 hp.
It was installed on cars of MMC, Proton automakers (manufactured in Malaysia):
The cylinder block of all modifications of the engine is cast iron.
The cylinder head is made of aluminum alloy. On different types of engines, one or two camshafts were placed in the head. The camshaft was located on four supports (SOHC), or on five (DOHC). Tent-type combustion chambers.
The exhaust valves of DOHC and DOHC-MIVEC engines are sodium filled.
Crankshaft steel, forged. It is located on four pillars.
The piston is standard, made of aluminum alloy, with two compression and one oil scraper rings.
Lubrication system with full-flow oil cleaning and its supply under pressure to rubbing units.
Closed cooling system with forced coolant circulation.
The ignition system for SOHC engines is contactless with a distributor, with one ignition coil. DOHC engines were produced without a distributor.
All models of power units are equipped with a forced crankcase ventilation system that prevents the release of exhaust gases that have broken into it.
Internal combustion engines with a variable valve timing system MIVEC (electronic valve lift control system depending on the crankshaft speed) have increased power and a low content of harmful substances in exhaust gases. Additionally, there is fuel savings. You can watch a video about how the system works.
Technical specifications
The characteristics of the three types of engine are summarized in the table.
| Manufacturer | MMS | MMS | MMS |
|---|---|---|---|
| Engine modification | SOHC | DOHC | DOHC-MIVEC |
| Volume, cm³ | 1998 | 1998 | 1998 |
| Power, HP | 145 | 150-170 | 200 |
| Torque, Nm | 171 | 180-186 | 200 |
| Compression ratio | 10,0 | 10,0 | 10,0 |
| Cylinder block | cast iron | cast iron | cast iron |
| Cylinder head | aluminum | aluminum | aluminum |
| Number of cylinders | 6 | 6 | 6 |
| Cylinder diameter, mm | 78,4 | 78,4 | 78,4 |
| Cylinder arrangement | V-shaped | V-shaped | V-shaped |
| Camber angle, deg. | 60 | 60 | 60 |
| The piston stroke, mm | 69 | 69 | 69 |
| Valves per cylinder | 4 | 4 | 4 |
| Hydraulic compensators | + | + | no |
| Timing drive | belt | belt | belt |
| Belt tension adjustment | roller | automatic | |
| Valve timing control | - | - | Electronic, MIVEC |
| Turbocharging | no | no | |
| Fuel system | Distributed Injection | injector | injector |
| Fuel | Gasoline AI-95 | Gasoline AI-95 | Gasoline AI-95 |
| Ecology norm | Euro 2 / 3 | Euro 2 / 3 | Euro 3 |
| Location | transverse | transverse | |
| Resource, outside. km | 300 | 250 | 220 |
Depending on the location of the timing belts and attachments (right or left), the tabular data of each type of internal combustion engine differ slightly from those given.
For a more detailed acquaintance with the device, maintenance and repair of the engine, follow the link.
Reliability, weaknesses, maintainability
Additional information about the engine that is of interest to every motorist.
Reliability
According to available information, 6A12 motors, subject to the rules for their maintenance and operation, easily overcome the resource limit of 400 thousand km. The reliability of the power unit depends on the attitude towards it from the driver.
In the operating instructions for the car, the manufacturer disclosed in detail all the issues of engine maintenance. But here one important point must be taken into account - for Russia, the maintenance requirements should be slightly changed. Specifically, the periods of run between the next maintenance have been reduced. This is caused by not quite high-quality fuel and lubricants and roads that differ from Japanese ones.
For example, when operating an internal combustion engine in difficult conditions, it is recommended to change the oil after 5000 km of the car's run. To improve the reliability of the engine, this distance will have to be reduced. Or pour Japanese quality oil into the system. Failure to comply with these conditions will significantly bring the overhaul closer.
Forum member Marat Dulatbaev writes the following about reliability (the author's style is preserved):
Thus, it is possible to speak with confidence about the high reliability of the unit with its proper maintenance.
Weak spots
The 6A12 motor has several weaknesses, the negative consequences of which can be easily reduced. The greatest danger is caused by a decrease in oil pressure. This phenomenon in most cases causes the inserts to rotate. Regular maintenance in compliance with all recommendations of the manufacturer is the key to the perfect operation of the engine.
Low timing belt resource (90 thousand km). When it is destroyed, the bending of the valves is inevitable. Replacing the belt after 75-80 thousand kilometers will eliminate this weak point.
Hydraulic lifters wear out quickly. The main reason is the use of low-quality oil. 6A12 power units of all modifications are considered "omnivorous" in terms of fuel, but are very demanding on the quality of the oil. Using cheap grades leads to costly engine repairs.
Maintainability
The maintainability of the motor is good. On the Internet, you can find a lot of information on this topic. Forum users in their messages post a detailed description of the steps for repairing an engine with their own hands. For clarity, attach a photo.
Parts are not a big problem either. In specialized online stores you can find any part or assembly. This type of repair, such as the use of donor engine spare parts, has become widespread.
But the best option for resolving the issue of repair is to entrust its implementation to specialists of a specialized car service.
All Mitsubishi engine modifications were reliable and durable. But very demanding on the quality of fuels and lubricants, especially oils.
