Toyota 3UR Engine is a naturally-aspirated, 5.7 L, water-cooled petrol engine. It was designed to fit for use in Toyota Tundra, Land Cruiser, Sequoia, and Lexus LX570 vehicles.
3UR engines or 3UR-FE in the Toyota community holds the same engine architecture as those 4.6 Liter V8, 1UR, in the Lexus 460. However, Lexus engines are indeed produced in Japan, but the only Toyota plant in the world that produces 5.7 V8s is in Alabama.
3UR’s engine block and heads were owned by Toyota and contained most of the North American influence engine ever made. With their Aluminum block construction and variable intake lengths, 3URs is considered one of the most advanced truck engines available to the public.
3UR engines have Dual VVT-i Variable Valve Timing System on both intake and exhaust camshafts without the D-4S gasoline direct injection.
It is also equipped with an L-type sequential fuel injection system (SFI), Electronic Spark Advance (ESA), Acoustic Control Induction System (ACIS), Electronic Throttle Control System-intelligent (ETCS-i), and Direct Ignition System (DIS) with individual coils on each spark plug.
It is also incorporated with a 3-way catalytic converter stainless steel exhaust manifold.
Toyota offered an E85 Ethanol capable option for the 2009 model year.
So let us talk about more of 3UR engines; their engine design, tuning potential, power, issues, components, aftermarket support, and overall impact in the community and automotive industry.
Engine Specifications and Design:
- Production Run: 2007 – Present
- Cylinder Head Material: Aluminum
- Cylinder Block Material: Aluminum
- Configuration: V8
- Bore: 94 mm
- Stroke: 102 mm
- Valvetrain: DOHC 32 Valves Per Cylinder, Chain-driven
- Displacement: 5.7 L (5,663 cc)
- Compression Ratio: 10.2
- Weight: 490 lbs.
- Max HP: 381 HP at 5,600 RPM, 504 HP (TRD Version)
- Max Torque: 401 lb-ft at 3,600 RPM, 550 lb-ft (TRD Version)
3UR engine block is made of a die-cast Bodine Aluminum – which Toyota owns, to go with eight cylinders at a 90-degree bank angle in a V arrangement. It has a bore of 94 mm, 102 mm stroke, and a 21 mm cylinder bank offset.
This engine produces 381 HP at 5,600 RPM and 401 lb-ft of torque at 3,600 RPM.
Inside the bores, you can trace spiny-type cast-iron liners designed for better adhesion between the Aluminum block and cylinder liners. This large irregular surface is cast externally to reduce heat deformation and improve the heat dissipation of the bores.
A coolant pathway is created in the 3UR-FE engine to lay a better avenue and a more relaxed water flow between the left and right cylinder banks, to the cylinder head, and the water jackets of each of the cylinder banks.
Along with the water jackets themselves, plastic spacers control the coolant flow to keep the cylinder walls at a regulated temperature.
To add, on the bulkheads of the cylinder block are air passage holes that reduce back pressure and pumping losses created by the reciprocal movement of the pistons due to improvement of the airflow at the bottom of the cylinders.
3UR has a forged steel crankshaft supported by five main bearing journals made of Aluminum alloy, while the bearing lining surfaces are resin-coated to improve seizure and wear resistance.
The bearing caps of the crankshaft have four plastic region tightening bolts which Toyota tightened laterally to enhance reliability, and of different sizes both on the inside and outer sides for added journal security. Also, the crankshaft pulley has a torsional rubber damper to reduce vibration and noise.
This engine also has forged connecting rods with resin-coated Aluminum bearings, and knock pins are used at the jointing surfaces of the bearings caps to minimize the bearing cap movements and shifting during assembly.
In addition, connecting rods have plastic region tightening bolts also.
The 3UR engine has an Aluminum alloy cylinder head and covers; double overhead camshaft per cylinder bank design made from cast-iron with four valves per cylinder, two for intake and two for exhaust.
The engine uses a separate primary timing chain for intake camshafts, and each exhaust camshaft is driven by a secondary timing chain connected to the intake shaft.
Aluminum pistons are planted in the bores and cooled by four oil jets in the cylinder block; the pistons skirts are resin-coated to improve wear resistance and reduce friction.
The top groove of the piston ring is Alumite coated, while the bottom of the piston head has cast holes; these are minor details yet play an essential role in abrasion resistance and weight reduction.
The cylinder heads are mounted on the three-layer steel laminate type head gasket and a shim about the cylinder for each head gasket to improve durability and sealing. These head gasket surfaces are coated with heat-resistant fluoro rubber.
Headcovers in the 3UR engine are like the windows inside the machine. They improve the ventilation inside it and prevent premature deterioration of the engine oil through the exemplary airflow drawn from the right and left cylinder covers.
In addition to that, an oil delivery tube is provided for lubrication of the sliding parts of the valve rocker arms.
Between the Aluminum cylinder block and the intake manifold, a plastic separator case is situated on that spot to separate the engine oil from the blow-by gases.
This is done through a system called inertial impaction where blow-by gases would acquaint and contact a baffle plate, comply and collect on the plate and then proceed downwards the drip.
Applications of the 3UR Engine:
- 2007 – Present Toyota Tundra
- 2007 – Present Toyota Sequoia
- 2007 – 2021 Toyota Land Cruiser 200 Series (the Middle East and US markets only)
- 2007 – Present Lexus LX 570
- 2009 – 2014 Toyota Tundra (E85 Version)
- 2009 – 2014 Toyota Sequoia (E85 Version)
Engine Tuning, Upgrades, and Modifications
The Toyota 3UR engines are incredibly reliable and a perfect fit for engine tuning and other upgrades. It has strong stock internals, exemplary engine design, produces tons of horses, and what more can we ask, right?
So Toyota came up with an offer, a bolt-on roots-type supercharger kit developed by the Toyota Racing Development (TRD) Eaton Corporation Twin Vortices Series. This is available on both Toyota Tundra and Sequoia and can be installed by dealers and entirely covered under warranty.
This supercharger kit will put your 3UR engine in steroids, no doubt, with its solid buff to your machine to a staggering 504 HP and 550 lb-ft of torque. However, Magnuson offered an improved version of the supercharger kit above, which will make the TRD version numbers sound rookie with its 550 HP output.
Problems Surrounding 3UR Engine:
No matter how reliable the engines are, there will always come a time where some issues might occur and get in the way that can either cost us a tremendous amount of money or time.
It does not mean that these problems do happen every time, but a lot of these are the results of unprepared episodes as owners and overseers. So here are some issues that might occur in the 3UR engine:
First is the Water pump problem, which is prevalent across Toyota engines, including the 3URs and other powerplants. This happens when the internal seals or bearings fail, and this is where leaking starts out of the weep hole; weep holes are, by design, allow the coolant to leak out.
Fortunately, 5.7 L V8s is not likely to break its water pump that much, but if it continues to leak incessantly, you need to replace it immediately so that it will not escalate into a more serious matter like overheating and engine breakage.
Usually, these pumps last for about 150,00 miles. Some indicators that you experience water pump failure are visible coolant leak, overheating, and low engine coolant.
Next is the cam tower. What is a cam tower, by the way? Well, to make it short, cam towers are located under the valve covers, and RTV sealants are used instead of gaskets.
We are not saying that sealants are weaker, but sealants wear down through time, and eventually, oil leaks start to develop. You can notice that leaks start towards the rear of the cam towers and allows the oil to drip onto the high-temperature exhaust manifold.
You might notice some visible leaks, burning oil smells, and white smoke coming from the engine bay if you have a faulty cam tower.
Summary
3UR engines are highly and highly reliable engines. With its power amounting to almost stage 3 tuned cars out there, you will not be unsatisfied with its power output. Its engine design is also excellent and does not differ much from its UR family, so that we can expect a lot of longevity right here.
The only problem or issue that we may see through this engine is the cam tower and water pump; though they are not detrimental and are replaceable, these will still raise some eyebrows for some.
But, overall, 3UR engines are solid and durable engines—high tuning potential with excellent power output and design.
I hope that this simple guide provided help for you to understand the basics, engine design, tuning potential, power, issues, and overall impact on the automotive industry and community.