The 4.0-liter V8 engine Toyota 1UZ-FE was assembled at the Tahara plant from 1989 to 2004 and was installed in the most powerful rear-wheel drive models of the Japanese concern at that time. There are two generations of the engine: 1989 without phase control and 1997 with VVT-i system.
Main characteristics of the engine Toyota 1UZ-FE
| Parameter | Value |
|---|---|
| Production | Tahara plant |
| Engine make | 1UZ |
| Years of production | 1989-2002 |
| Cylinder block material | Aluminum |
| Power system | Injector |
| Type | V-shaped |
| Number of cylinders | 8 |
| Valves per cylinder | 4 |
| Piston stroke, mm | 82.5 |
| Cylinder diameter, mm | 87.5 |
| Motor weight, kg | ~165 |
| Oil volume in the engine, l | 5.0 |
| Oil change is carried out, km | 7000-10000 |
| Engine life, thousand km | Factory: -, in practice: 400+ |
| Tuning potential, hp | up to 1000 (without loss of resource) |
Characteristics by generation 1UZ-FE
1UZ-FE (1989, non-VVVTi)
| Parameter | Value |
|---|---|
| Engine displacement, cm³ | 3968 |
| Power, hp | 250-260 @ 5400 rpm |
| Torque, Nm | 355-365 @ 4400 rpm |
| Compression ratio | 10-10.4 |
| Environmental class | Euro 2 |
1UZ-FE (1997, VVTi)
| Parameter | Value |
|---|---|
| Engine displacement, cm³ | 3968 |
| Power, hp | 290-300 @ 5900-6000 rpm |
| Torque, Nm | 400-420 @ 4000-4100 rpm |
| Compression ratio | 10.5 |
| Environmental class | Euro 3 |
Engine application
| Vehicle Model | Years of manufacture |
|---|---|
| Toyota Aristo 1 (S140) | 1991-1997 |
| Toyota Aristo 2 (S160) | 1997-2000 |
| Toyota Celsior 1 (XF10) | 1989-1994 |
| Toyota Celsior 2 (XF20) | 1994-2000 |
| Toyota Crown 8 (S130) | 1989-1991 |
| Toyota Crown Majesta 1 (S140) | 1991-1995 |
| Toyota Crown Majesta 2 (S150) | 1995-1999 |
| Toyota Crown Majesta 3 (S170) | 1999-2002 |
| Toyota HiAce 4 (H100) | 1989-2004 |
| Toyota Soarer 3 (Z30) | 1991-1997 |
| Lexus GS (S140) | 1991-1997 |
| Lexus GS (S160) | 1997-2000 |
| Lexus LS (XF10) | 1989-1994 |
| Lexus LS (XF20) | 1994-2000 |
| Lexus SC (Z30) | 1991-2000 |
Reliability, construction and repair of Toyota 1UZ 4.0 engine
The ancestor of the Toyota UZ family (which later included 2UZ and 3UZ), the 1UZ engine, appeared in 1989 and was intended for the top models of Toyota and Lexus. This 4-liter engine was intended to replace the old 5V motor and successfully coped with its task, along with gaining a reputation as one of the most durable and reliable Toyota engines.
The 1UZ-FE cylinder block is aluminum, with a 90° camber angle, with pressed thin cast iron liners. There are two aluminum cylinder heads, two camshafts per cylinder and 4 valves per cylinder. There are no hydrocompensators, so the 1UZ requires periodic valve adjustment.
Since 1995, the engine was slightly updated, light connecting rods were used (were 628 grams, now 581 grams) and pistons under the compression ratio of 10.4, and the power increased to 260 hp.
Since 1997, 1UZ-FE received VVTi system on the intake shaft, changed intake channels, increased diameter of intake and exhaust valves, changed cylinder-head gasket, used a long two-stage intake manifold ACIS, improved ignition system. Also on the 1UZ-FE VVTi used new pistons for increased to 10.5 compression ratio, as well as electronic throttle.
In the timing belt was used, its service life is 100 thousand kilometers. On versions without VVTi, the valves do not bend when the timing belt breaks. Versions with VVTi can not boast of this.
Production of this power unit continued until 2002, when it was displaced by the 4.3 liter 3UZ-FE.
Service Regulations
| Maintenance item | Periodicity | Volume/Type | Notes |
|---|---|---|---|
| Oil service | Every 10,000 kilometers | Oil 5W-30 or 5W-40 | Engine oil capacity – 6.3 liters; 5.6 liters required for replacement |
| Gas distribution mechanism | |||
| Transmission timing type | – | Belt | The timing belt lasts up to 100,000 km; in practice, up to 150,000 km |
| When the belt breaks/slips | – | Valve bending (VVTi version only) | |
| Valve thermal clearances | Every 100,000 km | Adjustment with washer selection | |
| Consumables replacement | |||
| Air filter | Every 40,000 km | – | |
| Fuel filter | Every 40,000 km | – | |
| Tank filter | Not to be replaced | – | |
| Spark plugs | Every 40,000 km | – | Frequently needs replacing |
| Auxiliary belt | Every 100,000 km | – | |
| Antifreeze | Every 3 years or 60,000 km | – |
Toyota 1UZ engine problems, defects and life
- Ignition system failures – spark plugs often do not last for their recommended life and can be difficult to replace.
- G timing belt failure – the complicated and costly procedure of replacing the timing belt results in it often being replaced late. It is especially important to carry out the replacement in time on versions with VVTi, because when the belt breaks, the valves bend.
- Small breakdowns – frequent oil leaks from the oil seals and unreliable pump. The pump is located on the timing belt, and its jamming can lead to serious damage.
Engine 1 UZ is the case when you have to look for flaws with a magnifying glass. 1UZ-FE does not have any design flaws, shortcomings and diseases. All faults occurring on these power units are most often associated with age, manner of operation or irregular maintenance. From low-quality gasoline can quickly die plugs, and their replacement is associated with some difficulties. The 1UZ-FE itself is extremely reliable and is often called a millionaire. This engine is able to pass 500 thousand kilometers and more.
Tuning the engine Toyota 1UZ-FE
Compressor
The first step on the way to increasing the power of 1UZ can be the purchase of a compressor kit based on Eaton M90. Such options have an intake manifold in the kit, and you also need to buy a fuel regulator. It is desirable to buy a straight-through exhaust and 4-2-1 manifolds. At a pressure of 0.4 bar, the motor 1UZ will be able to develop up to 330 hp. This is the most reliable and popular tuning for UZ.
To get even more power, you need to buy forged pistons under compression ratio 8.5, connecting rods, ARP studs, intercooler, injectors from 2JZ-GTE, Walbro 255 lph, exhaust 3″, VEMS brain and inflate 0.7 bar. That will be enough to get over 400hp.
1UZ turbo
On forged pistons of the above configuration, instead of a compressor, you can assemble a turbo node using a turbo kit based on a single Garrett GT40. Or buy yourself a turbine, intercooler, weld the manifold. You will also need a westgate, block-off, boost controller, oil drain, oil supply, thermal insulation, piping, clamps, VEMS brains. The 1UZ will end up making over 450hp.
1UZ twin turbo
Something similar can be made on the basis of two Garrett VNT25 turbos. Similar kits are sold and can easily be installed on a forged piston. This can provide over 500hp.
In any of the above cases, you can use more powerful superchargers, get serious about tweaking the engine, increase boost pressure, and take off as much power as possible.
ENGINE RATING: 5