Mitsubishi 6G72 engine
Content
This engine belongs to Mitsubishi's popular 6G series. Two types of 6G72 are known: 12-valve (single camshaft) and 24-valve (two camshafts). Both are 6-cylinder V-engines with increased camber angle and overhead camshafts/valves in the cylinder head. The lightweight engine that replaced the 6G71 remained on the assembly line for exactly 22 years, until the arrival of the new 6G75.
Engine description
Consider the main features of this engine.
- The engine crankshaft is supported by 4 bearings, the covers of which are combined into a bed to increase the rigidity of the cylinder block.
- The engine pistons are cast from aluminum alloy, connected by a floating pin to the connecting rod.
- Piston rings are cast iron: one has a conical surface with a bevel.
- Composite oil scraper rings, scraper type, endowed with a spring expander.
- In the cylinder head, tent-type combustion chambers are located.
- Engine valves are made of refractory steel.
- Hydraulic compensators are provided for automatic clearance adjustment in the drive.
The differences between SOHC and DOHC schemes deserve special attention.
- The camshaft of the SOHC version is cast, with 4 bearings, but the camshafts of the DOHC version have 5 bearings, fixed with special covers.
- The timing belt of the engine with two camshafts is adjusted by an automatic tensioner. The rollers are cast from aluminum alloy, have a long service life.
We note other features.
- Engine capacity is practically unchanged for various modifications - exactly 3 liters.
- The aluminum pistons are protected by a graphite coating.
- The combustion chambers are located inside the cylinder head, they are tent-shaped.
- Installation of direct injection GDI (on the latest modifications 6G72).
The most powerful in the modifications of the 6G72 engines was the turbo version, which develops 320 hp. With. Such a motor was installed on the Dodge Steel and Mitsubishi 3000 GT.
It is noteworthy that before the advent of the Cyclon family, MMC was completely satisfied with in-line fours. But with the advent of large SUVs, minivans and crossovers, there is a need for more powerful units. Therefore, in-line "fours" were replaced by V-shaped "sixes", and some modifications received two camshafts and a cylinder head.
The manufacturer focused on the following during the manufacture of new motors:
- trying to increase power, resorted to using a turbocharged version;
- trying to reduce fuel consumption, he modernized the valve system.
Oil consumption 6G72 has been increased to 800 g/1000 km due to some technical features. Overhaul can declare itself after 150-200 thousandth run.
Some experts explain a wide range of 6G72 modifications by the possibility of varying engine power. So, it can produce, depending on the version: 141-225 hp. With. (simple modification with 12 or 24 valves); 215-240 l. With. (version with direct fuel injection); 280-324 l. With. (turbocharged version). Torque values also differ: for conventional atmospheric versions - 232-304 Nm, for turbocharged ones - 415-427 Nm.
As for the use of two camshafts: despite the fact that the 24-valve design appeared earlier, the DOHC scheme was used only from the beginning of the 90s of the last century. Earlier 24-valve versions of the engine had only one camshaft. Some of them used GDI direct injection, which increased the compression ratio.
The turbocharged version of the 6G72 is equipped with an MHI TD04-09B compressor. Two coolers are paired with it, since one intercooler is not able to provide the required air volume for six cylinders. In the new version of the 6G72 engine, upgraded pistons, oil coolers, nozzles, and sensors have been used.
Interestingly, for the European market, 6G72 turbo engines came with a TD04-13G compressor. This option allowed the power plant to reach a power of 286 liters. With. at a boost pressure of 0,5 bar.
On which cars was installed 6G72
Mark | Models |
Mitsubishi | Galant 3000 S12 1987 and Galant 1993-2003; Chrysler Voyager 1988-1991; Montero 3000 1989-1991; Pajero 3000 1989-1991; Diamond 1990-1992; Eclipse 2000-2005. |
Dodge | Stratus 2001-2005; Spirit 1989-1995; Caravan 1990-2000; Ram 50 1990-1993; Dynasty, Dayton; Shado; Stel. |
Chrysler | Sebring Coupe 2001-2005; Le Baron; TS; NY; Voyager 3000. |
Hyundai | Sonata 1994-1998 |
Plymouth | Duster 1992-1994; Akklaim 1989; Voyager 1990-2000. |
Technical specifications
Engine model | 6G72 GDI |
Volume in cm3 | 2972 |
Power in l. With. | 215 |
Maximum torque in H*m at rpm | 168(17)/2500; 226 (23) / 4000; 231(24)/2500; 233(24)/3600; 235 (24) / 4000; 270 (28) / 3000; 304 (31) / 3500 |
Maximum RPM | 5500 |
engine's type | In type 6 cylinder DOHC/SOHC |
Compression ratio | 10 |
Piston diameter in mm | 91.1 |
Stroke in mm | 10.01.1900 |
Fuel used | Gasoline Premium (AI-98); Gasoline Regular (AI-92, AI-95); Gasoline AI-92; Gasoline AI-95; Natural gas |
Fuel consumption, l / 100 km | 4.8 – 13.8 |
Add. engine information | 24-valve, with electronic fuel injection |
CO2 emission in g / km | 276 – 290 |
Cylinder diameter, mm | 91.1 |
Number of valves per cylinder | 24.01.1900 |
The mechanism for changing the volume of cylinders | no |
Supercharger | No |
Start-stop system | no |
Oil consumption | maximum 1 l / 1000 km |
What kind of oil to pour into the engine by viscosity | 5W30, 5W40, 0W30, 0W40 |
Which oil is best for the engine by manufacturer | Liqui Moly, Lukoil, Rosneft |
Oil for 6G72 by composition | synthetics in winter, semi-synthetics in summer |
Engine oil volume | 4,6 l |
Working temperature | 90° |
Internal combustion engine resource | declared 150000 km |
real 250000 km | |
Adjustment of valves | hydraulic compensators |
Cooling system | forced, antifreeze |
Coolant volume | 10,4 l |
water pump | GWM51A from manufacturer GMB |
Candles on 6G72 | PFR6J from NGK Laser Platinum |
Candle gap | 0,85 mm |
Timing belt | A608YU32MM |
The order of the cylinders | 1-2-3-4-5-6 |
Air filter | Bosch 0986AF2010 filter cartridge |
The oil filter | Toyo TO-5229M |
Flywheel | MR305191 |
Flywheel Bolts | М12х1,25 mm, length 26 mm |
Valve stem seals | manufacturer Goetze, inlet light |
graduation dark | |
Compression | from 12 bar, difference in adjacent cylinders max. 1 bar |
Turnovers XX | 750 - 800 min -1 |
Tightening force of threaded connections | candle - 18 Nm |
flywheel - 75 Nm | |
clutch bolt - 18 Nm | |
bearing cover - 68 - 84 Nm (main) and 43 - 53 Nm (connecting rod) | |
cylinder head - 30 - 40 Nm |
Engine modifications
Modification name | Features |
12 valves simple modification | driven by a single SOHC camshaft |
24 valve simple modification | driven by a single SOHC camshaft |
24 valves DOHC | controlled by two DOHC camshafts |
24 valves DOHC with GDI | DOHC scheme, plus GDI direct injection |
24 valves with turbocharger | DOHC scheme, plus an additional attachment for the intake tract - a turbocharger |
Advantages and disadvantages
The reliable and high-life design of the 6G72 engine saves the owner from additional costs. If the owners of the 6G71 had to go to the service station every 15 thousand kilometers to adjust the valves, then things are much better with the new engine.
However, some shortcomings remained. In particular, this concerns the complexity of maintenance, overheating and destruction of valves.
- Engine maintenance is complicated due to the fact that the cylinder head is divided into two parts. In addition, such a scheme affects the increase in oil consumption - excess lubrication is used to maintain hydraulic lifters.
- Overheating of a powerful engine is inevitable in the urban driving cycle, when the engine just needs to be “restrained”, activating only low speeds.
- The valves are bent due to the frequent slipping of the timing belt. Automatic adjustment helps eliminate the break, but the belt slips in certain situations and still bends the valves.
Another disadvantage of the 6G72 is the variety of engine designs. This complicates the repair, since the schemes of components and sets of internal combustion engines with one and two camshafts are completely different.
The nuances of routine maintenance
One of the main issues in the maintenance schedule for a 3-liter engine is the replacement of the timing belt after a 90th run. Even earlier, every 10 thousand kilometers, the oil filter must be changed. Learn more about scheduled maintenance.
- Replacement of oxygen sensors every 10 thousand kilometers.
- Exhaust manifold check every two years.
- Control of the fuel system and crankcase ventilation after 30 thousand kilometers.
- Battery recharge and replacement every 3-4 years.
- Refrigerant change and a thorough revision of all hoses, connections at the turn of 30 thousand kilometers.
- Installation of new gasoline filters and air cartridges after 40 thousand kilometers.
- Replacement of spark plugs every 30 thousand kilometers.
Major faults
Let us consider in detail the popular "sores" of the 6G72, which make it an average unit that cannot be called super-reliable.
- Swimming speed after starting is caused by clogging of the throttle and the development of the XX regulator. The solution involves cleaning, repairing and replacing the sensor.
- An increase in fuel consumption indicates the development of valve stem seals and the occurrence of piston rings. Obviously, these elements will need to be replaced.
- Knocks inside the engine, which is explained by the development of the connecting rod bearing shells and the wear of the hydraulic tappets. The solution involves replacing the liners and hydraulic lifters.
According to the manufacturer, the use of good quality fuel (gasoline with an OC not lower than AI-95) guarantees a long engine life.
Modernization
Designers initially laid great potential in this engine. Without loss of resource, it can easily develop 350 hp. With. Experts recommend not to upgrade with turbocharging. In their opinion, the following changes can be made.
- Increase the diameter of the muffler and reflash the electronics.
- Replace the standard springs with a force of 28 kg with more powerful models that can withstand 40 kg.
- Rebore seats and install larger valves.
Note that atmospheric tuning will make it possible to increase power by 50 liters. With. Alteration of 6G72 will cost much less than a swap (engine replacement).