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1UZ is the primary engine of the UZ range, which also included 2UZ and 3UZ. Being first released in 1989, this 4.0L motor served as an alternative to Toyota 5V, being as efficient and trustworthy as its predecessor. The brand utilized this motor for the biggest Toyota and Lexus vehicles.
1UZ-FE features an aluminum cylinder block with DOHC 90° V8 configuration and thin cast-iron sleeves. Connecting rods are 146 mm long. Having 2 aluminum heads, it’s a twin cam motor with four valves on cylinder. Due to the absence of hydraulic lifters, motor requires some regulations from time to time. 1UZ have the firing order 1-8-4-3-6-5-7-2. The flow rate of 1UZ-FE injector is 220cc/min.
The motor was subjected to modification in 1995. Toyota employed lighter rods (581 g instead of 628 g) and pistons with higher compression index of 10.4. Capacity was equal to 260 hp while the 1UZFE flow rate increased to 251cc/min. In 1997, VVTi systems were introduced as well as long two-stage intake manifold, known as ACIS. The other changes were in cylinder head seals, inlet ports, bigger sizes of inlet and exhaust valves, ignition system. Restyled pistons had the compression rate of 10.5 and electronic throttle body.
Timing belt was present in all 1UZ-FE motors. It can run for 50,000-60,000 miles (100,000 kilometers). All the models without VVTi have valves, which keep their form even if timing belt is broken.
In 2002, Toyota stopped the manufacture of 1UZ-FE and substituted it with 4.3L 3UZ-FE.
|Also called||Toyota 1UZ|
|Cylinder block alloy||Aluminum|
4 valves per cylinder
|Piston stroke, mm (inch)||82.5 (3.25)|
|Cylinder bore, mm (inch)||87.5 (3.44)|
|Displacement||3969 cc (242.2 cu in)|
|Power output||188 kW (256 HP) at 5,400 rpm
192 kW (261 HP) at 5,400 rpm
213 kW (290 HP) at 5,900 rpm (VVTi)
220 kW (300 HP) at 6,000 rpm (VVTi)
|Torque output||353 Nm (260 lb·ft) at 4,400 rpm
365 Nm (269 lb·ft) at 4,400 rpm
407 Nm (300 lb·ft) at 4,100 rpm (VVTi)
420 Nm (310 lb·ft) at 4,000 rpm (VVTi)
|HP per liter||64.5
|Weight, kg (lbs)||165 (364)|
|Fuel consumption, L/100 km (mpg)
|for Lexus LS400
|Oil consumption , L/1000 km
(qt. per miles)
|up to 1.0
(1 qt. per 750 miles)
|Recommended engine oil||5W-30
|Engine oil capacity, L (qt.)||5.0 (5.3)|
|Oil change interval, km (miles)||5,000-10,000
|Normal engine operating temperature, °C (F)||–|
|Engine lifespan, km (miles)
-No life span loss
- 1989–2000 Lexus LS 400/Toyota Celsior
- 1989–2002 Toyota Crown/Toyota Crown Majesta
- 1991–2000 Lexus SC 400/Toyota Soarer
- 1992–2000 Lexus GS 400/Toyota Aristo
- Toyota MR2 Le Mans Car
1UZ-FE Engine Problems
The motor is very durable and can run for 300,000 miles. If to take care of it properly and examine regularly, you will prevent the engine tapping, oil leakage and high oil consumption.
After the motor runs more, the troubles with water pump, alternator and starter are possible. And it’s rather hard to remove a starter. The fuel quality may influence the work of spark plugs, which are rather costly. Use only high-quality fuel to prevent spark plug failure as its replacement is hard and expensive.
1UZ Generation 2, released since 1994, and VVTi motors are inclined to major damage in case of timing belt break. So, it’s recommended to control the condition of timing belt and replace it with a fresh one on time. Simultaneously, 1UZ Generation 1 features more powerful pistons, connecting rods and some other details. Though its capacity is lower, it’s more durable and reliable. Besides, it allows a vehicle to move more smoothly.