Toyota 1UZ-FE 4.0L Engine Specs, Problems & Reliability

Here in this post, I have gathered information about the Toyota 1UZ-FE 4.0L Engine from its official website, including its specifications, Problems, and Reliability.

We believe in providing reliable information to our readers, therefore we prefer to obtain information on the Toyota 1UZ-FE 4.0L Engine from authentic sources.

This article, which has been updated, has all the information you require about the Toyota 1UZ-FE 4.0L Engine.

The 1UZ-FE is the first of its kind in the UZ engine family. From 1989 until 2002, when it was superseded by the 3UZ-FE engine, Toyota and Lexus provided a 4.0-litre V8 gasoline engine in their high-end and performance vehicles.

The 1UZ engine eventually took the place of the Toyota V family’s antiquated design, which was in use from the 1960s through the 1990s.

Toyota 1UZ-FE 4.0L Engine

The 1UZ-FE motor uses an aluminium cylinder block with thin cast-iron cylinder liners. The cylinder banks in the engine block are at a right angle to one another.

There is a 21-mm dislocation between the cylinder banks. There are eight balance weights on the forged steel crankshaft in the engine, and it has six primary bearings.

The engine featured lightweight and strong forged steel connecting rods, aluminium pistons, and induction-hardened connecting rod pins to reduce rotational mass.

The 1UZ crankshaft, FE’s connecting rods, piston pins, and pistons were all changed and made lighter in late 1994. The engine has a stellar reputation for its low noise and silky performance.

Engine Specifications

Engine code 1UZ-FE
Layout Four-stroke, V8
Fuel type Gasoline (petrol)
Production 1989-2004
Displacement 4.0 L, 3,968 ccs (242.1 cu in)
Fuel system Before 1994: Multi-port fuel injection (MFI)
After 1994: Sequential multi-point fuel injection (SFI)
Power adder None
Power output From 259 PS (191 kW; 256 HP) at 5,400 rpm
to 300 PS (221 kW; 296 HP) at 6,000 rpm
Torque output From 333 N·m (34 kg·m, 245.4 ft·lb) at 4,000 rpm
to 420 N·m (42.8 kg·m, 309.5 ft·lb) at 4,600 rpm
Firing order 1-8-4-3-6-5-7-2
Dimensions (L x W x H):

Cylinder head

Blockhead alloy Aluminium
Valve Arrangement: DOHC, belt drive
Cylinder head height:
Valves: 32 (4 valves per cylinder)
Intake valve timing: Non VVTi (before 1994): 224°
Non VVTi (after 1994): 232°
VVTi (after 1997): 230°
Exhaust valve timing: Non VVTi (before 1994): 229°
Non VVTi (after 1994): 229°
VVTi (after 1997): 229°
Valve head diameter: INTAKE Before 1997: 33.5 mm (1.3189 in)
After 1997: 34.5 mm (1.3583 in)
EXHAUST Before 1997: 28.0 mm (1.1024 in)
After 1997: 29.0 mm (1.1417 in)
Valve stem diameter: INTAKE Before 1997: 5.970-5.985 mm (0.2350-0.2356 in)
After 1997: 5.470-5.485 mm (0.2154-0.2159 in)

Before 1997: 5.965-5.980 mm (0.2348-0.2354 in)
After 1997: 5.465-5.480 mm (0.2152-0.2157 in)

Valve clearance (Cold)

Intake valve 0.15-0.25 mm (0.006-0.010 in)
Exhaust valve 0.25-0.35 mm (0.010-0.014 in)

Compression pressure

Standard 12.5 kg/m2 / 300 rpm
Minimun 10.0 kg/m2 / 300 rpm
Compression differential limit between cylinders 1.0 kg/m2 / 300 rpm

Oil system

Oil consumption, L/1000 km (qt. per mile) up to 0.5 (1 qt. per 1200 miles)
Recommended engine oil 5W-30
Oil type API SH
Engine oil capacity (Refill capacity) Dru fill: 6.0 L (6.3 US qt, 5.3 Imp.qts)
With filter change 4.8 L (5.1 US qt, 4.2 Imp.qts)
Without filter change 4.5 L (4.8 US qt, 4.0 Imp.qts)
Oil change interval, km (miles) 10,000 (6,000)
Oil Pressure Idle speed: 29 kPa (0.3 kg/cm 2, 4.3 psi) or more
3,000 rpm: 294 – 588 kPa (3.0 – 6.0 kgf/cm 2 , 43 – 85 psi)

Ignition system

Spark plug NGK: BKR6EP-11
Spark plug gap 1.1 mm (0.0433 in)
Spark plug tightening torque 18 Nm (1.8 kg⋅m, 13 ft-lb)

Cylinder block

Cylinder block alloy Aluminium
Compression ratio: 1989-1994: 10.0:1
1994-1997: 10.4:1
1997-2004: 10.5:1
Cylinder bore: 87.5 mm (3.44 in)
Piston stroke: 82.5 mm (3.25 in)
A number of piston rings (compression/oil): 2 / 1
A number of main bearings: 5
Cylinder inner diameter (standard): 87.500-87.510 mm (3.4449-3.4453 in)
Piston skirt diameter (standard): 87.470-87.480 mm (3.4437-3.4441 in)
Piston compression height:
Piston pin outer diameter: 21.997-22.009 mm (0.866-0.8665 in)
Connecting rod bushing inner diameter: 22.005-22.014 mm (0.8663-0.8667 in)
Piston ring side clearance: Top 0.020-0.060 mm (0.0008-0.0024 in)
Second 0.015-0.055 mm (0.0006-0.0022 in)
Piston ring end gap: Top 0.250-0.450 mm (0.0098-0.0177 in)
Second 0.350-0.600 mm (0.0138-0.0236 in)
Oil 0.150-0.500 mm (0.0059-0.0197 in)
Crankshaft main journal diameter: 66.988-67.000 mm (2.6373-2.6378 in)
Crankpin diameter: 51.982-52.000 mm (2.0465-2.0472 in)

Toyota 1UZ-FE 4.0L Engine Problems & Reliability

The 1UZ engine was the inspiration for Toyota’s UZ series (which included the 2UZ and 3UZ). Appearing in 1989, it was made for the highest-end Toyotas and Lexuses.

The previous Toyota 5V was upgraded to this new 4-litre motor. Both have earned a reputation as powerful and dependable Toyota engines.

aluminium 1UZ-FE V8 cylinder block with thin cast-iron cylinder sleeves produced by pressing.

146 millimetres is the standard length for rods made to specification 1UZFE. It has a twin-cam, four-valve, aluminium-head cylinder.

Because 1UZ lacks hydraulic lifters, it requires routine valve adjustments.

Engines powered by Toyota 1UZs have a specific firing order of 1-8-4-3-6-5-7-2. The standard 1UZFE engine has 220 cc/min injectors.

The engine has had minor upgrades since 1995. The high-compression pistons (CR = 10.4) and the lightweight rods (581 g, compared to 628 g in the previous iteration) are the main differences.

The engine now has 260 horsepower. 1UZ-FE stock fuel injectors have a flow rate of 251 cc/min.

Since 1997, 1UZ-FE engines have been upgraded with a Variable Valve Timing with Intelligent Control (VVTi) system (intake cams), revised inlet ports, enlarged inlet and exhaust valves, a new cylinder head gasket, a lengthy 2-stage intake manifold (ACIS), and a new ignition system.

New pistons with a compression ratio of 10.5 are employed in the 1UZ-FE VVTi, along with an electronic throttle body.

The timing belt is used in every 1UZFE engine ever made. In terms of mileage, it can go between 50,000 and 60,000. (100,000 km).

If the timing belt fails, the valves won’t bend during any updates without the variable valve timing system (VVTi).

Toyota 1UZ-FE 4.0L Engine Review 

The 1UZ-FE Toyota 4.0L V8 engine has been considered to be among the best and most reliable motors ever created. It first appeared in 1989 with the Lexus LS 400 and went on to power a broad variety of Toyota and Lexus automobiles for more than two decades. For a full review, please check this YouTube video Here.

Toyota 1UZ-FE 4.0L Engine FAQ 

Is the 1UZFE a reliable engine?

The 1UZ-FE was an overengineered marvel, but it was ultimately doomed in motorsport.

Despite being the result of a far-fetched plan, this particular eight-cylinder engine is remembered as one of the finest and most dependable in history.

How long does a 1UZ engine last?

Despite what you may have heard, 300,000 miles is not a small amount. Quite a few engines didn’t make it that far.

Still, the 1UZ’s durability is remarkable. It doesn’t knock, leak, or waste any oil if you keep it in good condition.

How good is the 1UZFE?

Consumer Reports states that a 1UZFE engine should run for more than 200,000 miles with no problems.

We have seen 1UZFE engines that have doubled that mileage and still run strong with routine upkeep.

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