Together with 4GR-FSE, in 2003, Toyota introduced the 3.0 L displacement engine for the GR engine family. It replaced the internationally recognized inline-six engine, the 2JZ-GE. This engine uses the same Aluminum 60 degree V6 cylinder block as 2GR. However, the cylinder’s diameter of 3GR is smaller. Also, these engines feature different cooling systems. Other than the 3GR engine, the Toyota GR series includes the following models: 1GR, 2GR, 4GR, 5GR, and 6GR.
So today, we will discuss the 3GR engine and its versions – the basic 3GR-FE and 3GR-FSE. Its engine design, power output, applications, issues, and everything that correlates to this engine.
Engine Specifications and Design
- Production Run: 2003 – Present
- Cylinder Head Material: Aluminum
- Cylinder Block Material: Aluminum
- Configuration: V6
- Bore: 87.5 mm
- Stroke: 83 mm
- Valvetrain: DOHC 4 Valves Per Cylinder
- Displacement: 3.0 L (2994 cc)
- Compression Ratio: 10.5 (3GR-FE) and 11.5 (3GR-FSE)
- Weight: 384 lbs.
- Max HP: 256 HP at 6,200 RPM
- Max Torque: 231 lb-ft at 3,600 RPM
Toyota 3GR engines are designed for Rear-Wheel Drive longitudinal mounting; 3GR-FE wears the badge representing the Toyota 3GR line. This engine is equipped with Dual VVT-i variable valve timing technology and was first installed in the Lexus cars with 300 index and other Toyota vehicles. 3GR machines are substantially similar to 2GR engines but only with a smaller displacement and layout. The rated power output of the 3GR-FE engine is 228 HP at 6,400 RPM and 221 lb-ft at 4,800 RPM.
Toyota’s 3GR-FE cylinder block is made from cast Aluminum Alloy and a spiny type cast-iron cylinder liners cast into the block; this irregular surface allows a better bond between the Aluminum cylinder block and the liners.
It has a bore of 87.5 mm, obviously sharing the same stroke with 2GR with 83 mm, and a compression ratio of 10.5. The cylinder banks of the 3GR engine have a 60-degree V angle; to go with a bank offset of 36.6 mm. The external walls of the block were curved and used reinforced ribs to couple with the transmission. Besides, drilled passages or spacers in the water jacket allow more intensive coolant circulation near the top of the cylinder. This improves thermal efficiency and heat dissipation.
3GR-FE is also equipped with an ETCS or Electronic Throttle Control System, which allows the ECM to facilitate the closing and opening of the throttle valve based on the driver’s demand through the accelerator pedal. At the same time, it positions the throttle valve under different driving conditions and RPM range to deliver optimum performance. It also supports the SNOW operation mode, a damping response to the pressing of the accelerator pedal.
The oil filter of 3GR is installed horizontally, right in the front, on the top of the upper sump bracket; front engine mounts are liquid-filled, active braces are not applied. Toyota also installed an ATF heater or warmer in the cooling system mounted on the throttle valve body cover, reducing the oil viscosity friction by increasing the oil temperature under cold conditions. This greatly improves fuel efficiency and prevents transaxle oil from overheating while the vehicle is moving.
Its fuel system has a return line, and the fuel pressure regulator is built in the fuel pump module, which is run by the ACIS that operates under the exact algorithm of those 1GRs.
The Toyota 3GR engine uses two DOHC Aluminum Cylinder heads with a variable valve timing system (Dual VVT-i) on the intake and exhaust camshafts. These alloyed cast-iron camshafts have induction hardened cams and were divided at the cam journals. They have been slightly revised for it uses two-layer metal type head gaskets and used shims around the bores for better durability and sealing. In addition, it uses a multipoint injection system and variable-length intake manifold ACIS (Acoustic Control Induction System) technology.
To add to that, this engine has a forged steel crankshaft, which is made from cast-iron with five balance weights and four journals; the crankshaft bearing caps are tightened from the bottom with four bolts using the plastic region tightening method.
3GR-FE’s connecting rods were made of sintered forged steel and had narrow connecting rod bearings to reduce the friction; crankshaft bearings were made from Aluminum. The Bigger end of the connecting rod has a 56.0 mm inner diameter, while the smaller end has a 22.0 mm inner diameter.
To go with that, 3GR-FE uses hyper eutectic Aluminum pistons, instead of the forged ones, for tighter skirt clearances and added strength. This composition also improves the resistance to scuffs and seizures and mainly operated at lower temperatures. It has a shorter compression height and streak-finished plastic-coated shorter skirts for seizure resistance. Oil jets are installed in the block to spray oil into the cylinders to improve durability and reduce friction within the walls and the pistons.
Applications of 3GR-FE
- 2003 Toyota Crown (GRS182 for China and Asia-Pacific)
- 2005 Toyota Reiz (GRX121 for China)
- 2005 Lexus GS 300 (GRS190 for the Middle East and Asia-Pacific)
- 2007 Lexus IS 300 and Is 300 C (GSE22 for Middle-East and the Asia Pacific)
- Hongqi HQ3
Toyota also produced a 3GR engine version with a direct fuel injection system which is known as D4 direct injection, and this engine is called 3GR-FSE. The fundamental changes of this engine are modified intake ports, optimized pistons, different spark plugs, and an increased compression ratio of 11.5. This engine produces 252 HP at 6,200 RPM and 231 lb-ft of torque at 3,600 RPM.
Application of 3GR-FSE
- 2004 Toyota Mark X (GRX121 for Japan)
- 2003 Toyota Crown Royal and Athlete (GRS182/183 for Japan)
- 2005 Lexus GS 300 (GRS190/195 for Europe and North America)
- 2008 Toyota Crown Royal (GRS202/203 for Japan)
- 2006 – 2009 Toyota Mark X Supercharged (316 HP)
Engine Tuning, Upgrades, and Modifications
3GR engines are designed for city life and city driving, used for daily commutes and other errand stuff. So for any upgrades to work and achieved, you need to spend serious cash for this one. However, if you want to do it, you will need some performance parts such as a performance exhaust system and cold air intake; this can increase the engine power but will not cure the itch. So with that, you need to buy a TOMS 3GR supercharger kit and install it on the stock internals, and it can deliver more than 300 HP and 288 lb-ft of torque. Then, buy a 3-inch performance exhaust system and get more power.
Toyota 3GR engines are somehow similar to the 2GR engines; therefore, they share most of the issues. However, we will cover some problems here that are a common occurrence among 3GR engines but not necessarily affected the significant number of the production numbers.
The first and the most known problem is the oil leak. An oil leak in the 3GR engine is due to the breakage of the rubber section of the oil tube in the VVT-i lubrication system. This breakage is the leading cause of a rapid oil loss in the engine; oil starvation may lead to severe engine damage – camshaft beds and crankshaft bearings. However, oil loss can only be determined when the oil pressure warning indicator lights up. This issue so big and endangering to the vehicles, Toyota announced a recall service campaign.
Another usual and weakest point problem of the 3GR engine is the water pump leaks and noise. This consumable has a service of around 30,000 miles. Water pumps are vital for engine operation as it provides the coolant circulation and problems such as this restrict the proper coolant flow that will create a ripple that results in overheating. Again, normal wear and tear is the primary suspect of this.
Some reports show that there is noise from the headcover area at starting, and the possible errors are related to valve timing. This issue is common on 1GR, 2GR, and 3GR engines. The root of this problem is the VVT-i sprocket. Therefore, it is recommended to replace the valvetrain components of the sprockets with the camshafts and carriers assembly.
Additional issues are idle speed control problems that can be solved by replacing the throttle body assembly or cleaning it. Detrimental errors due to poor valve maintenance; and alternator pulley one-way clutch failure, which is associated with VVT control valves
Toyota also raised major recall campaigns, and the concern was raised over valve springs. This issue is due to having either foreign matter in the material or spring ruptures; corrosion of Aluminum components of the fuel system that leads to the destruction of welding, cracks, and significant fuel leaks; defects of injector ring seals; and spontaneous loosening of the fuel pressure sensor.
Toyota 3GR engines are city driving and commute cars that can produce substantial power outputs. It has that same charisma that the 2GR, which is pseudo-origin but having a smaller displacement for better fuel economy and reliability. This Rear-Wheel Drive motor can serve for many years with the proper maintenance and care. Though it has some minor issues and weak points, such as the water pump and VVT-i tube, that does not equate to a bad engine. Overall, this engine, compared to 2GR, is a far more reliable and pretty solid engine for an everyday drive.
I hope that this simple guide may help you understand the 3GR engine more. Its characteristics, engine design, power, torque, and overall impact on the automotive industry and community.