Japanese automakers have been the wolf pack leader in terms of reliability and power output with the mix of economic use throughout the years. And for sure, one of the top dogs in the engine department is the 3.0 L 2JZ-GE engine which debuted in the late ’70s from the then Supra Celica to rival Nissan’s Z engines.
This engine paved the way for the Supra six-cylinder lines.
So today, we will talk about the wonders of the 2JZ-GE engines. Its engine design, power output, tuning potential, issues, aftermarket support, and overall impact on the industry.
What are 2JZ-GE Engines?
The Toyota 2JZ-GE engine is a naturally-aspirated, straight-six, 3.0 L gasoline engine from the Toyota JZ family. It replaced the previous 7M-GE engine and more inclined to run best with medium to high engine speed ranges.
2JZ-GE features a cast-iron block, aluminum cylinder head, belt-driven double overhead camshafts with four valves for each cylinder, and wide-angled valves. It is also equipped with an L-type electronically controlled, multiport sequential fuel injection system or SFI and VVT-i system (Variable Valve Timing with intelligence) since 1997.
In addition to that, the 2JZ-GE engine has an integrated throttle body and Idle Air Control (IAC) into a single uniform unit. It used a conventional throttle body wherein the throttle valve opening is dictated by the effort exerted on the accelerator pedal; the more vigorous effort means a broader valve opening. Electronic Throttle Control System or the ETCS-i system is added to this particular VVT-i version as well as DIS (Distributorless Ignition System) and Electronic Spark Advance (ESA). The ECU of the 2JZ-GE engine also calculates the optimal opening of the valves according to the different driving conditions. It uses a control motor for the opening of the throttle valves.
Engine Specifications and Design:
- Production Run: 1991 – 2007
- Cylinder Head Material: Aluminum
- Cylinder Block Material: Cast-iron
- Configuration: Inline-six
- Bore: 86 mm
- Stroke: 86 mm
- Valvetrain: DOHC with four valves per cylinder
- Displacement: 3.0 L (2997 cc)
- Compression Ratio: 10.0 (Without VVT-i) and 10.5 (with VVT-i)
- Weight: 507 lbs.
- Max HP: 227 HP at 6,000 RPM
- Max Torque: 224 lb-ft at 5,800 RPM
The 2JZ-GE has two generations since its production. The early generation engine used a mechanical distributor ignition system and was manufactured from 1991 to 1996. This version produces 227 HP at 6,000 RPM and 206 lb-ft of torque at maximum and a compression ratio of 10.5. The second generation, which was manufactured the following year, integrated with the VVT-i system on the intake camshaft at the exact timetable, though others followed later in 1997. It also has a DIS-3 ignition system with three ignition coils. This engine has a 10.5 compression ratio, too; 227 HP at 6,000 RPM and 224 lb-ft of torque at 4,000 RPM.
Toyota’s 2JZ-GE engine block is made of cast iron that utilizes a seven-bearing support system with a skeleton structure that includes eleven oil returns, blow-by gas passages, and two central oil holes. It has a 86 mm bore and a 86 mm stroke. The external walls of the engine are curved to reduce noise and enhance the engine rigidity. Moreover, the alternator, air conditioning compressor, and other ancillary components are attached directly to the cylinder block.
The crankshaft has twelve counterweights and seven journals which both of the journals and pins are induction-hardened to increase their rigidity. The crankshaft also operates on Aluminum bearings, and the bearing caps are fitted inside through the use of plastic region tightening bolts.
The 2JZ-GE is equipped with a dual-mode crankshaft damper pulley, which combines a bending damper and torsional damper to reduce the vibration on both torsional and bending movements.
The connecting rods are hot-forged with each connecting rods, and connecting rod caps are joined via knock pins and plastic region tightening bolts. At the smaller end of connecting rod, a bimetal bushing is press-fitted onto the piston pin hole; on the bigger end of the connecting rod, an oil jet spray oil is mounted underneath the pistons for cooling.
2JZ-GE engines with a VVT-i system have connecting rods made of high-strength vanadium steel to reduce weight due to the engine’s higher power output. Toyota reduced the skirt portion a little bit to reduce weight as well as reduced piston valve recess to improve combustion efficiency.
The pistons are made of special cast Aluminum and are fitted with a single oil ring and two compression rings. It also has slot-less type oil return holes on the oil ring grooves to regulate lower temperatures hovering in the top ring groove. The top surface of the compression ring is chromium-plated; the piston skirt areas are coated with resin, and the side rails of the oil rings had undergone treatment with a gas nitriding process; all of these are designed to reduce the friction.
The 2JZ-GE cylinder head is made from lightweight, but strong aluminum mounted on a single-layered metal gasket and used a plastic region for bolt tightening. The head has small-diameter intake ports as well as sub-water jackets for the cooling of the intake ports. This innovation contributed to improved intake airflow velocity and increased torque production at low to medium engine speed range.
To add to that, 2JZ-GE with VVT-i system has a modified cylinder head water jacket to improve the cooling around the spark plugs to allow the compression ratio to increase. The cylinder head covers are made from high-strength magnesium to reduce weight, and cylinder head cover gaskets are made from acrylic rubber.
The engine has two overhead camshafts made of specially cast steel and heat-treated bearing caps; camshafts are driven via a timing belt. It has four heat-resistant steel valves per cylinder and equipped with seven journals, six of those are located between the two camshafts. The belt-driven camshafts have an automatic tensioner composed of a spring and an oil damper to maintain the tension. For the 2JZ-GE VVT-i engine, an oil passage has been made to supply the engine and right to the VVT-i system.
The 2JZ-GE engine uses an L-type electronically-controlled, multiport sequential fuel injection system. The air is introduced from the throttle body, air pipe, and air gallery that flows through the air chamber under the fuel injector and eventually mixed onto the fuel in this system. The air-fuel mix is sent in each cylinder every two revolutions.
In addition, the 2JZ-GE engine has a pentroof type of combustion chamber with spark plugs situated near the chamber center to improve the anti-knocking performance.
Applications of the 2JZ-GE Engines:
- Toyota Altezza AS300
- Lexus IS300
- Toyota Aristo
- Lexus GS300
- Toyota Crown/Toyota Crown Majesta
- Toyota Mark II
- Toyota Chaser
- Toyota Cresta
- Toyota Origin
- Toyota Progres
- Toyota Soarer
- Lexus SC300
- Toyota Supra
Engine Tuning, Upgrades, and Modifications
The 2JZ-GE engine is already an excellent engine to be proud of but if you are still finding the power output that can satisfy you, try upgrading the 1JZ-GE. I recommend buying the turbocharged version; 2JZ-GTE is far more practical in terms of costs because they will produce more power and have better internals.
But if you still want to proceed, you need to buy performance aftermarket cams, Individual throttle bodies, mounting an aftermarket intake system, headers, performance exhaust system, and some head porting.
You can also buy a 2JZ-GE turbo kit, Garrett GTX30, or the likes, with a complete set of details, bolt-in on the 2JZ-GTE pistons for the internals, or a 3-mm cylinder head gasket. Finally, purchase an 80 mm throttle body and have the ECU tune. This can give you at least 450 horsepower.
Problems Surrounding 2JZ-GE Engines:
The 2JZ-GE engine shares most of its problems with its younger brother, the 1JZ-GE engine. That’s not uncommon because they have the same cylinder block and head, and they only differ in their displacements and some features. But the overall engine design is almost the same. So, with that, I think it would help if we let the common issues and problems of the engine, from previous or current owners of the machine, come through and spread so that the other will have an idea of these issues. It is better to expect something wrong before it happens, and that will significantly cost you less due to preparedness through proper maintenance and care. Here are some issues that might affect the 2JZ-GE engine:
First is the knocking sound in the engine. Knocking sound in the 1JZ-GE engine is usually caused by the VVT-i system, connecting rod bearings, and unadjusted intake and exhaust valves. Always check the valve clearances and do it to start the process. If you eliminated the noise after checking the clearances, then the problem lies in the valves but if not, replace the VVT-i system with a new one. The belt tensioner also causes annoying sounds but does not directly contribute to engine knocking.
Next is the engine won’t start. Unable to start the engine is the face of reality; it is frustrating and, at the same time, affects your focus. This is mainly caused by spark plugs and more common in colder areas because some spark plugs became damp or frozen in these conditions.
And if the problem as mentioned above is not addressed as soon as possible, it can lead to misfiring. Misfiring happens when the engine cylinder cannot burn the air-fuel mixture in the combustion chamber; mainly due to defective or worn-out engine components such as spark plugs, piston ring, MAF sensors, oxygen sensors, etc. When an engine cannot get a hold of its power, it jerks aggressively, resulting in excessive fuel consumption and raised emissions output.
Next is the rough idling on some 2JZ-GE engines. Rough idling is so common that wide varieties of the engine are affected by this. Rough idling is when the air-fuel mixture is burned inconsistently in the combustion chamber. This is due to the accumulated dirt on fuel injectors, clogged air filters, spark plugs and wires, and exhaust system issues.
And lastly, the excessive oil consumption. This is because 2JZ-GE engines are built decades ago, especially if you are buying second-hand ones. Some of the internal components there are already loose or straight-up worn-out that need to be replaced.
The 2JZ-GE engine is a highly safe, durable, and relatively reliable engine. It can easily pass the 300,000-mile lifespan with proper maintenance and by using high-quality engine oil. This engine is not only an excellent platform to perform tuning, but it also housed many vital features that will stay in Toyota for years to come. The integration of the DIS ignition system, pentroof combustion chamber, oil passage, and overall better fuel economy and consumption. Pretty solid engine for its age.
I hope that this simple instruction and guide helped you understand the 2JZ-GE engine’s engine design, power output, applications, issues, problems, aftermarket support, tuning potential, and overall impact on the automotive industry and community.