Mitsubishi 4G64 Engine Review: Specs, Problems and Reliability

The Mitsubishi 4G64 engine is a part of the Sirius family and is shared by many other engines, including the 4G63, 4G63T, 4G61, 4G62, and others. It was released in 1989 for the Fifth-Generation Mitsubishi Galant model.

The Mitsubishi 4G64 engine is made in Shenyang by SAME and assembled through semi-knockdowns for complete knockdown kits. The first regular assembly took place in April 2000.

The Mitsubishi 4G64 engine produces the most torque at 3,500 rpm for enhanced power and usability when driving. Moreover, it does this while also delivering class-leading fuel economy.

Mitsubishi 4G64 engines and the more common 4G63 engines share many characteristics. The most popular variant of the latter is the 2.4 Liter displacement engine, which eventually replaced its predecessor, the 4G54. Engine blocks for both are cast from similar materials as well- closed deck block design with no oil jets to dampen piston movement- but there are significant differences between them that can be seen by looking at their height: a taller block on the former engine by 6 mm, a larger bore size and an increased stroke both result in having higher compression ratio relative to its smaller counterpart; this also results in better power output and overall performance for enthusiasts who value these statistics.

The Mitsubishi 4G64 engines have a 100-mm long-stroke crankshaft, and compression height is increased from 85 mm (4G63) to 86.5 mm in 4G64s. The connecting rods were also adjusted by 150mm and weighed 34.83 lbs, while the Chrysler versions feature fracture-split forged powder metal connecting rods for supporting pistons at 38 lbs weight only.

4G64 Engine Specs

Manufacturer	Shenyang Aerospace Mitsubishi Motors Engine Manufacturing Co Ltd Shiga Plant
Also called	Sirius
Production	1983-nowadays
Type	In-line
Valve per cylinder	MIVEC intake
Oil pump type	Involute gear type
Cooling system	Water-cooled forced circulation
Water pump type	Centrifugal impeller type
EGR system	Single type
Injector type and number	Electromagnetic 4
Injector identification mark	N275H
Throttle position sensor	Variable resistor type
Closed throttle position switch	Contact switch type, incorporated in idle speed control motor-TRUCK Movable contact type, incorporated in throttle position sensor – EXPO
Number of cylinders	2 4
Total displacement, cc	2,351
Cylinder bore mm	86.5
Piston stroke mm	100
Compression ratio	8.5 9 9.5 11.5
Power output h.p at rpm	112/5000 124/5000 132/5250 150/5000 150/5500
Torque output, Nm/rpm	184/3500 189/3500 192/4000 214/4000 225/3500
Fuel consumption, for Eclipse III city highway combined	10.2 7.6 8.8
Oil consumption, L/1000 km (qt. per miles)	up to 1.0 (1 qt. per 750 miles)
Recommended engine oil	0W-40, 5W-30, 5W-40, 5W-50, 10W-30, 10W-40, 10W-50, 10W-60, 15W-50
Engine Oil Capacity, L	4.0
Oil change interval, km (miles)	7,000-10,000 (4,500-6,000)
Engine lifespan, km (miles) -Official information -Real	– 400,000+ (245,000+)
Tuning, HP -Max HP -No life span loss	1000+ –

The 4G64 2.4L engine requires 4.5 US Quarts (4.3 Liters) of new SAE 5W-20 oil for an oil change with a new oil filter.

Valve Timing

Intake valve Open BTDC	20” 19”
Intake valve Close ABDC	64” 57”
Exhaust valve Open BBDC	64” 57”
Exhaust valve Close ATDC	20” 19”

Torque Specifications

	Nm	ft.1b.s.
Cooling fan bolt	11	8
Water pump pulley bolt – Engine without cooling fan	9	7
Water pulley bolt pump – Engine with the cooling fan	11	8
Generator brace bolt	14	10
Generator mounting bolt	24	17
Generator pivot nut	23	17
Crankshaft pulley bolt	25	18
Spark plug	25	18
Distributor nut	11	8
Ignition coil bolt	14	10
Ignition power transistor nut	18	13
Tensioner bolt	49	35
Tensioner spacer	49	35
Oil pumps sprocket nut	55	40
Crankshaft sprocket bolt	120	87
Tensioner “B” bolt	19	14
Silent shaft sprocket bolt, right	46	33
The engine supports bracket bolt, left	36	26
Camshaft sprocket bolt	90	65
Throttle body bolt – SOHC	12	9
Fuel rail bolt	12	9
Fuel pressure regulator bolt	9	7
Throttle position sensor bolt	2	1.4
Idle speed control motor bolt	3.5	2.5
Idle air control motor bolt	3.5	2.5
Turbocharger wastegate actuator bolt	12	9
Bearing cap bolt M8x25 M8x65	24 20	17 14
Cylinder head bolt	95	69
Oil bolt	7	5
Oil filter bracket bolt	19	14

What Cars Have The 4G64?

• 1993-1997 Mitsubishi Chariot
• 1988–2006 Mitsubishi Delica/Van
• 1997-1999 Mitsubishi Eclipse GS Spyder Convertible FWD model equipped with a 141 hp (105 kW) 2.4 L 16-valve SOHC
• 2000-2005 Mitsubishi Eclipse
• 1994–2003 Mitsubishi Galant
• 1990–present Mitsubishi L200
• 1996–1998 Mitsubishi Magna (codenamed 4G64-S4 and fitted to the TE-TF series)
• 1990–1996 Mitsubishi Mighty Max
• 1998-2005 Mitsubishi Montero (V11 – 2 door) Latin America version
• 2001 Mitsubishi Airtrek
• 2003 Mitsubishi Outlander
• 1987–1990 Mitsubishi Sapporo
• 1986-2005 Mitsubishi Triton
• 2005 Mitsubishi Zinger
• 2003-2006 Kia Sorento 2.4i Manual
• 2004–present Brilliance BS6
• 2008–present Chery V5
• 1983–1992 Dodge Colt Vista (AWD only)
• 1990–1992 Dodge Ram 50
• 2006–present Great Wall Hover(X240 and V240)
• 1986-1998 Hyundai Grandeur
• 1989–1991 Hyundai Sonata
• 1999–2005 Hyundai Sonata
• 2001 Hyundai Santa Fe
• 2000–2005 Kia Optima
• 1998-2003 Mitsubishi Space Wagon

Sealant

	Specified sealant	Quantity
Rocker cover	3M ATD Part No. 8660 or equivalent	As required
Semi-circular packing	3M ATD Part No. 8660 or equivalent	As required
Oil pan gasket	MITSUBISHI GENUINE PART MD970389 or equivalent	As required
Engine coolant temperature gauge unit	3M ATD Part No. 8660 or equivalent	As required
Engine coolant temperature sensor	3M Nut Locking Part No. 4171 or equivalent	As required
Oil pressure switch	3M ATD Part No. 8660 or equivalent	As required
Oil pressure gauge unit	3M ATD Part No. 8660 or equivalent	As required

Mitsubishi 4G64 Engine Problems and Reliability

Mitsubishi’s 4G64 engine is identical to its 4G63 and shares many things including wear, problems, and issues. If you are concerned with premature or excessive wear of any part of the 4G64 engine’s parts or components, these observations should help keep your vehicle running smoothly and efficiently for years to come:

The vibration is most commonly felt on the left-hand side of the engine. If this happens, replacing loose engine mounts can fix it!

The main problem with the Mitsubishi 4G64 engine is vibration caused by its imbalance. The balance shaft aims to reduce this, but poor engine oil choices increase the risk of insufficient oil flow and a lack of hydraulic lifters means it can give out prematurely.

Rough idle can be attributed to neglect such as dirty air filters, fuel injectors and ECT sensors. Try checking these parts every now and again for changes or replacements.

The 4G64 has a hydraulically lifted head; This means you avoid having to adjust the valves yourself. In contrast, the Sirius family of engines requires the belt to be replaced at least every 60,000 miles.

4G64T Engine

In terms of turbo options, there are just two to consider: 4G64 SOHC and 4G64+4G63. For the former, you will need an EVO turbocharger, EVO header pipe, EVO intercooler, 560cc fuel injectors and radiator in order to upgrade your engine. The latter requires additional electronic components such as ECUs.

• an Evo turbocharger
• an Evo header
• an Evo intercooler + pipes
• a 2.5″ exhaust system
• an Evo fuel pump or Walbro 255 lph
• 560cc fuel injectors (Evolution)
• a large radiator (e.g., Mishimoto)

A second option, the Mitsubishi 4G64 with Evo head, will produce better results. You’ll need a Mitsubishi Evolution head and all its respective equipment.

The list of main OEM and aftermarket parts:

• an Evolution head
• 150mm connecting rods (e.g., Manley)
• ARP rod bolts
• 87mm forged pistons
• an Evo intake system
• Evo spark plugs
• Evo ignition coils
• an Evo fuel system
• 750 cc fuel injectors
• a Walbro 255 fuel pump
• an Evo turbo
• an Evo header
• a 3″ exhaust system from the beginning to the end.

Let’s go over some changes and additions to the list.

• a cold air intake
• a Mishimoto radiator
• a 3″ ETS intercooler and pipes
• an AMS intake manifold
• Kelford 272 cams
• adjustable cam gears
• valve springs and retainers
• an FP Green turbo + a manifold
• an Aeromotive fuel rail
• an Aeromotive fuel pressure regulator
• 1,000 cc fuel injectors
• an Aeromotive 340 lph
• a TiAL bypass valve
• an Evo turbo

The 4G64 cylinder block is notoriously rough on the balance shafts, so you will have to do some modification in order for your engine to produce an optimal 500 HP.

Your 4G64 turbo will then need refining + oil jets installed in the heads (to prevent dry starts) and extra-large valves giving out with valve springs and bronze guides.

4G64 Destroker

The 4G64 engine has a high rod-to-stroke ratio that is advantageous for reaching high revolutions. However, the reduction in displacement comes from long rods and short stroke camshafts which result in a 2.1l engine.

This can be remedied by taking a 4G64 block or using one of these blocks with an existing 4g63 that results in an 88mm crankshaft length. 156mm connecting rods are needed, as well as installation of oil jets into the block before you install your destroker kit due to ACL bearings and around 8 hours, work on average time per crank to have it ready.

The information provided in this article is for general informational purposes only. The author and publisher make no representations or warranties of any kind, express or implied, regarding the accuracy, adequacy, validity, reliability, availability, or completeness of any information presented. The reader is advised to consult a qualified professional, such as a mechanic or dealership, before making any decisions related to their vehicle's engine oil or maintenance.