4G69 2.4 Sirius Engine Specs, Problems, Reliability

The 4G69 engine is a development of the Japanese concern Mitsubishi, it is part of a group of engines called Sirius, similar to other “star” engines: Astron, Orion, Saturn.

The engine marking is standard, where the first digit is the number of cylinders, the letter indicates the type of fuel, and the last digits indicate the block type and engine number in the series. As an additional marking, the presence of a turbocharger may be indicated.

4G69 – four-cylinder gasoline engine with a volume of 2.4 liters. Production started in 2003. Represents an improved model 4G64, especially for installation on more “heavy” cars, such as Mitsubishi Outlander and Grandis. Release in Japan ended in 2013, after which the production license was officially transferred to Chinese manufacturers.

Despite the fact that quite a lot of components from 4G63 and 4G64 are used in its production, the engine is fundamentally different from the latter, especially in terms of the use of spare parts for repairs.

Read Also: G54B / 4G54 2.6 Engine Specs, Problems, Reliability

4G64 Vs 4G69 Engine Specs

The 4G69 cylinder block is made of cast iron. It has a greater height compared to the 4G64 and an increased diameter of pistons and cylinders. The pistons themselves are lightened, as are the crankshaft and connecting rods. Comparative characteristics of some masses and sizes:

Technical solutions applied in the engine design:

• in-line engine design;
• gas distribution mechanism with overhead camshafts (SOHC type);
• variable valve timing type MIVEC;
• long-stroke connecting rod and piston group. It was this feature that required a reduction in the masses of pistons, crankshaft and connecting rods;
• the use in the production process of not only a cast-iron cylinder block, but also the cylinder liners themselves;
• single shaft gas distribution system. Only one camshaft is used to control the intake and exhaust valves;
  one balance shaft.

The use of the MIVEC system allows you to increase the overall engine power by about 13% due to:

• valve lift control (8%);
• a higher rate of supply of the fuel-air mixture (2.5%);
• better release, due to a larger opening of the exhaust valves and a modified exhaust manifold (1.5%);
• increasing the volume of the combustion chamber (1%).

But the use of just one camshaft to control both intake and exhaust valves does not allow the installation of hydraulic lifters. Therefore, the manufacturer recommended that they be adjusted every 30-40 thousand mileage.

It should be noted that in addition to the “standard” engine, GDI models equipped with a direct fuel injection system were produced. In this case, the fuel is fed directly into the combustion chamber, which allows you to remove large engine per volume. For such engines, the compression ratio was increased to 11.5.

Structurally, the MIVEC system is represented by:

• low profile cams and rockers for one type of valve;
• medium profile cams and rockers for another type of valve;
• high profile cams, which “links” low and medium cams together;
• T-arms integral with high profile cams.

When operating at high speeds, the system raises both intake or exhaust valves equally, which corresponds to the standard mode, as on conventional internal combustion engines. But when you release the gas pedal or lower the rotation speed, the amount of lift changes.

One of the intake or exhaust valves opens, for example, completely, but the second only opens slightly. Thus, when the engine is running, the most economical operation of the engine is achieved when driving in the urban cycle, the fuel burns more efficiently, the environmental friendliness of the engine improves, with a simultaneous increase in torque.

It is worth noting that the use of MIVEC technology made it possible to somewhat reduce the risk of damage to the piston crown, valve disc and valve stem when the timing belt breaks. The risk of damage increases with increasing engine speed. Critical, according to the manufacturer, is the value of 3200 rpm.

Full Specifications of the 4G69 Engine

4G69 Engine Performance Summary

Here, we will investigate the characteristics of this engine by referring to the data of the 4G69 type naturally aspirated engine installed in Mitsubishi’s NA4W type Grandis S 2007/07 model.

Mitsubishi’s NA4W type Grandis S
Vehicle model	DBA-NA4W type
Car name & grade	Grandis S
Engine model	4G69
type	In-line 4-cylinder
Displacement	2378cc
Inner diameter x stroke	87.0 mm x 100.0 mm
Bore stroke ratio	1.15
Single cylinder volume	594.5cc
Compression ratio	9.5
Intake method	Naturally aspirated
Fuel used	Regular gasoline
Maximum output	165PS / 6000rpm
Maximum torque	22.1kgm / 4000rpm

First of all, as a basic structure, the 4G69 type engine is a long stroke type engine with a bore (inner diameter) of 87.0 mm, a stroke (stroke) of 100.0 mm, and a bore stroke ratio of 1.15 (the stroke amount is larger than the piston diameter).

When the displacement and the number of cylinders are the same, the engine has better torque characteristics in the low rpm range than the short stroke type and is easy to handle, but in the high rpm range, the filling efficiency deteriorates and the sliding resistance increases. There is a concern that the output will drop.

Moreover, when the number of revolutions is the same, the average piston speed tends to be higher than that of the short stroke type, so the load on the engine tends to be heavier.

Among the models registered on this site, the oldest model equipped with the 4G69 type naturally aspirated engine is the first Airtrek [CU5W type | 2004/04] released from 2001/06, and the newest model is 2003. It is the 4th generation Grandis [NA4W type | 2007/07] released from / 05, and all 4 models of NA cars are registered, 4 models of NA cars, and 0 models of turbo / SC cars are registered.

Evaluation from the viewpoint of transient characteristics and liter equivalent horsepower

Image of engine performance curve
Changes in horsepower	123.4PS → 165PS
Transition of torque	22.1kgm → 19.7kgm
Liter horsepower	69.39 PS / L
Liter torque	9.3kgm / L

Grandis’s in-line 4-cylinder 2378cc engine with a compression ratio of 9.5 and regular gasoline specifications, which is the reference vehicle for this time, produces a maximum output of 165 horsepower at 6000 rpm and a maximum torque of 22.1 kgm at 6000 rpm.

If you know the horsepower and the number of revolutions, you can know the torque, and if you know the torque and the number of revolutions, you can know the horsepower. The torque at 6000 rpm is 19.7kgm.

The horsepower per liter of displacement is 69.39PS / L and the torque is 9.3kgm / L, and the horsepower per cylinder (single cylinder volume 594.5cc) is 41.2PS and the torque is 5.5kgm.

When the 4G69 naturally aspirated engine is applied to a 10-step evaluation based on the deviation value aggregated from all NA vehicles registered on this site, the evaluation is ” standard ” with a converted horsepower of [ 5 ] and a converted torque of [ 5 ]. It is categorized as an engine with a typical output (bottom of the middle).

By the way, among the models equipped with the 4G69 type engine, the one with the highest output was the NA4W type Grandis 165PS / 22.1kgm, and the smallest was the CU5W type Airtrek 160PS / 21.9kgm.

Displacement increase, compression ratio increase, bore stroke ratio change

There are three factors that determine the engine displacement: the number of cylinders, the bore diameter, and the stroke amount. By increasing or decreasing these, engines with various displacements are created.

Here, regardless of whether it is actually possible, the displacement when the piston diameter is expanded from the genuine 87.0 mm to 90.0 mm in 0.5 mm increments and when the stroke is extended from the genuine 100.0 mm to 105.0 mm in 1 mm increments. And, the change of the compression ratio when it is assumed that the volume of the combustion chamber does not change is listed.

* It is easy to say stroke up, but if you want to make a long stroke, you need a crankshaft and a compatible connecting rod, and if you can not divert it, you have to make it in one-off, so it is expensive anyway. It is a menu that requires considerable preparedness to put out.

Regarding the compression ratio, in most cases, the uneven capacity of the top surface of the piston changes as the diameter of the piston increases, so the compression ratio values ​​in the list do not match, but the displacement. Please enjoy the atmosphere that the compression ratio will naturally increase as you increase the size.

B / S ratio is an abbreviation for bore stroke ratio, and as the bore diameter is widened, the characteristics of the long stroke type, square type, or short stroke type are approached. In the case of 4G69 type engine, the ratio changes from 1.15 to 1.11 when the bore is increased by +3.0mm from the genuine piston.

Increased displacement with engines with similar piston diameters

There are 27 engines with pistons that are close in size to the piston diameter of 87.0 mm for the 4G69 type engine, so let’s calculate the displacement when the piston is diverted and the bore is increased as a sideshow.

Engines with similar piston diameters are Mitsubishi: 6B31 type 2997cc 87.6mm mounted on the CW6W type Outlander, Subaru: EJ18 type 1820cc 87.9mm mounted on the BD2 type legacy, Subaru: mounted on the GF4 type Impresa sports wagon. EJ16 type 1597cc 87.9mm, Mitsubishi: 4B12 type 2359cc 88.0mm mounted on CW5W type Outlander, Suzuki: H27A type 2736cc mounted on TD94W type Escudo 88.0mm, Lexus: 1LR mounted on LFA10 type LFA 88.0mm of type 4805cc is applicable.

(Although the number of people who find pleasure in such a quest has decreased) No matter how close the diameter is, there are factors such as the diameter of the piston pin, the height of the piston, and the convenience of valve recess, so if possible, the same manufacturer, If possible, if you choose the same fuel and the same intake method, and if possible, the one with a similar displacement, the possibility of genuine diversion may increase.

Average piston speed

Next, let’s look at the average piston speed. The average piston speed at 6000 rpm, where an engine with a stroke of 100.0 mm produces maximum output, is 20.0 m / s, which is a piston speed that travels a distance of 20.0 meters per second (72.0 km / h at speed). It means that is moving up and down.

At 4000 rpm, which produces the maximum torque, 13.3 m / s, and when 6500 rpm, which is 500 rpm higher than 6000 rpm, which produces the maximum output, is assumed to be the rev limit, the average speed is 21.7 m / s.

For reference, I calculated the change in piston speed when a 4G69 engine with a stroke of 100.0 mm is rotated up to 10000 rpm. Looking at this, it seems that the speed increases by approximately 6.65 m / s as the number of revolutions increases by 2000 revolutions.

Considering only 20.0 m / s, which is a guideline for general engines assuming mass production, it is mechanical to set the upper limit of high rpm to about 6000 rpm (whether it rotates or not). It seems to be preferred both mentally.

4G69 Engine Problems And Reliability

Since the 4G69 design itself is a continuation of the already “run-in” 4G64, there are not so many problems during its operation. It is imperative that the owner of this engine must take into account – the resources of the engines working in conjunction are interconnected. That is, if the roller or balance shaft bearing fails or needs to be replaced in time, the balancer belt, as well as the timing, must be replaced at the same time.

Even with a slight malfunction of the balancer bearing, it is wedged. As a result, an increased load on the timing belt, further, severe wear and breakage of the teeth. At best, the car will simply stall, at worst, a broken belt with damaged valves.

One of the factors for increased bearing wear is poor quality engine oil, its low level in the system, or a dirty oil filter or oil intake.

Engine vibrations are another common problem with the 4G69. Most often it occurs due to wear or damage to the engine mounts. As a rule, the left one most often fails due to design features.

Another reason for vibrations is the occurrence of compression and oil scraper (less often) rings during long-term sedimentation. The use of simple means for decoking solves the problem.

But the use of internal engine cleaners for these purposes is not recommended, since simultaneously with the release of the rings, all internal surfaces and deposits are cleaned of deposits, getting into the lubrication channels contribute to accelerated wear of the timing mechanism. And in particular, they accelerate the wear of the balancing shaft bearing.

Idle speed instability. Occurs due to failure of the regulator, contamination of the throttle valve, or with faulty injectors. The problem is quite standard and is solved by flushing and adjusting faulty engines, or replacing them with new ones.

4G69 Engine Maintainability and upgrade

The 4G69 engine is repaired without any problems. This is due to the availability of a wide range of spare parts, which, in some cases, can be used from kits for 4G64 and 4G63.

Most often require replacement:

• oil scraper rings;
• valve stem seals;
• valve cover gasket, crankshaft and camshaft seals;
• oil intake, if there was a blow to the pan due to its proximity to the wall;
• the presence of cast-iron sleeves allows you to bore to the next repair size.

Separately, it should be noted the excellent possibility of tuning the 4G69 engine. Since the possibilities for lightening the masses of pistons and connecting rods have already been chosen by the manufacturer, turbochargers are installed, turning an ordinary “aspirated” into a turbocharged one.

Especially for the 4G69 engine, RPW produces several kits that include everything you need to install supercharging, including all necessary gaskets and fasteners.

According to the manufacturer, after installing their kit, the engine is capable of developing power up to 300 hp.

The delivery includes:

• air pump with a capacity of 255 liters per hour;
• nozzles, increased productivity;
• cylinder head from Lancer Evolution;
• intercooler for air cooling;
• additional oil pump for the turbine;
• modified camshaft for correct operation in turbocharging mode.

Due to the fact that after installation the valve timing changes, and the engine runs on a qualitatively different working mixture, chip tuning of the engine is necessary. That is, the engine ECU itself is changing (corrected).

Oil for 4G69 Engine

For engines manufactured in Japan, the manufacturer recommends the use of oils with a viscosity of 5W-30 and the ACEA A3 / B4 standard. However, it is stipulated that when operating the car in conditions of low or high temperatures, these values ​​\u200b\u200bmust be adjusted, in accordance with the ambient temperature. The SAE table shows this clearly:

Thus, for temperatures:

• from -35 to -30, oil with the first index 0W is required;
• from -30 to -25 – 5W;
• from -25 to -20 – 10W;
• from -15 to -20 – 15W;
• from -10 to -15 – 15W oils can be used.

Chinese manufacturer for year-round use Total Quartz 9000 Energy 0W-30 oil. This type of oil meets the ILSAC GF-5 specification, has a reduced phosphorus content, which allows the exhaust aftertreatment system to work more efficiently and, as a result, reduces fuel consumption. The oil change interval is every 8000 km.

Service Interval For 4G69 Engine

• Timing belt replacement – 80,000 km;
• valve clearance adjustment – 30,000 km;
• cleaning the crankcase ventilation system – once every two years;
• fuel filter replacement – 20,000 km;
• air filter replacement – annually;
• replacement of antifreeze – 40,000 km;
• spark plugs – 20,000 km;
• the intake manifold and catalyst may need to be replaced after 60,000 km.

Cars on which 4G69 is installed

Japan:

• Mitsubishi Eclipse 2006 – 2012
• Mitsubishi Galant 2004 – 2012
• Mitsubishi Lancer 2004 – 2006
• Mitsubishi Outlander 2004 – 2006
• Mitsubishi Pajero Sport 2008 – 2016
• Mitsubishi Challenger 2008 – 2016
• Mitsubishi Grandis 2003 – 2011
• Mitsubishi Zinger since 2008 (only for models with automatic transmission)

China

• BYD S6 2011 – 2013
• Great Wall Haval H3 2008 – 2013
• Great Wall Haval H5 since 2009
• Geely EC8 2011 – 2014

America

• JMC Vigor Pick-up 4×4 since 2012

Conclusion

An updated version of 4G64, under the name 4G69, was released in 2003 on Mitsubishi Grandis and Mitsubishi Outlander cars and became the latest representative of the Sirius engine family (which, in addition to our engine, also included: 4G63T, 4G61, 4G62, 4G63, 4G64, 4G67, 4G69, 4D65 and 4D68).

In the new engine, the height of the cylinder block was reduced to 229 mm relative to its predecessor, the cylinder diameter was increased to 87 mm (was 86.5 mm), lightweight pistons were installed (278 g versus 354 g on 4G64), a light crankshaft (14.9 kg versus 15.8 kg on 4G64 ) and connecting rods (530 gr vs. 623 gr).

The cylinder head is installed new, with a system for changing the valve timing on the intake shaft and the height of the MIVEC valves, the diameter of the intake valves has increased to 34 mm, exhaust to 30.5 mm.

There are no hydraulic compensators on the 4G69, so every 40-50 thousand km it is necessary to adjust the valves, the clearances of the inlet valves for hot 0.2 mm, exhaust 0.3 mm.