Toyota 1AZ-FE

The Toyota 1AZ-FE is a 2,0 l (1,998 cc, 121.93 cu-in) straight-four 4-stroke natural aspirated gasoline engine from Toyota AZ-family. This engine was manufactured by Toyota Motor Company from 2000 on Kamigo Plant and Shimoyama Plant.

The Toyota 1AZ-FE features a lightweight aluminum block with thin cast-iron cylinder liners and aluminum head with two camshafts (DOHC) and four valves per cylinder (two intakes and two exhaust). The 1AZ-FE engine has VVT-i (Variable Valve Timing with intelligence) for intake side, Sequential MPFI fuel injection system, Toyota DIS “Direct Ignition System” with ignition coil for each spark plug. The 1AZ-FE engine is also equipped with “Electronic Spark Advance” (ESA) system, which selected optimal ignition timing in accordance with inputs from sensors.

An 86.0 mm (3.39 in) cylinder bore and 86.0 mm (3.39 in) piston stroke give the 1AZ-FE motor a total of 1,998 cc (121.93 cu-in) of displacement. Compression ratio rating is 9.8:1.

The engine produces from 147 PS (108 kW; 145 HP) at 6,000 rpm to 152 PS (112 kW; 150 HP) at 6,000 rpm of maximum horsepower and from 190 Nm (19.4 kg·m; 140.2 ft·lb) at 4,000 rpm to 193 Nm (19.7 kg·m; 142.4 ft·lb) at 4,000 rpm of peak torque.

The breakdown of the engine code is as follows:

• 1 – 1-st generation engine
• AZ – Engine family
• F – Economy narrow-angle DOHC
• E – Multi Point Fuel Injection

General information

Cylinder block

The 1AZ-FE has an open-deck die-cast aluminum cylinder block with cast-iron liners and a die-cast aluminum lower crankcase and a stamped oil pan. The forged steel crankshaft is fully balanced with eight counterweights and supported by five main bearings.

The connecting rods and caps are made of high-strength steel. To reduce engine weight, nut-less type plastic region tightening bolts are used. The engine used aluminum pistons with two compression and single oil ring. The cylinder bore is 86.0 mm (3.39 in) and the piston stroke is 86.0 mm (3.39 in). Compression ratio rating is 9.8:1.

Main bearing cap bolts tightening procedure and torque specs:

• Step 1: 20 Nm; 2.0 kg·m; 15 ft·lb
• Step 2: 40 Nm; 4.0 kg·m; 29 ft·lb

After securing bearing cap bolts, make sure crankshaft turns smoothly by hand.

Connecting rod bearing bolts

• Step 1: 25 Nm; 2.5 kg·m; 18 ft·lb
• Step 2: Turn bolts 90°

Cylinder head

The cylinder head is made of strong, light aluminum alloy which gives it good cooling efficiency. Each camshaft is supported by five bearings. The dual overhead camshafts are driven by a single-stage roller chain. The camshafts act on four valves per cylinder via bucket tappets. Valve diameters are 34.0 mm (1.3 in) for intake and 29.5 mm (1.2 in) for exhaust.

For the pre-2003 1AZ-FE engine, intake duration was 236 degrees and exhaust duration was 228 degrees. For the upgraded version of the 1AZ-FE engine that was introduced in late 2003, intake duration was 243 degrees and exhaust duration 220 degrees.

The 1AZ-FE engine used electronically controlled sequential fuel injection system with 12-hole injector nozzles that are mounted in the inlet ports.

Head tightening procedure and torque specs:

• Step 1: 79 Nm; 8.0 kg·m; 58 ft·lb
• Step 2: Turn all bolts 90°

Camshaft bearing cap bolts

• № 1:30 Nm; 3.0 kg·m; 22 ft·lb
• Other:9 Nm; 0.9 kg·m; 6.4 ft·lb

Maintenance data

Valve clearance adjustment data

Calculate the thickness of new adjusting valve lifter so valve clearance comes within specified values.

R = Thickness of removed valve lifter
N = Thickness of new valve lifter
M = Measured valve clearance

Intake:
N = R + [M – 0.24 mm (0.009 in)]
Exhaust:
N = R + [M – 0.35 mm (0.014 in)]

Valve lifters are available in 35 sizes to range from 5.06 mm (0.1992 in) to 5.74 mm (0.2260 in), in steps of 0.02 mm (0.0008 in).

Example (intake valve):
R = 5.12 mm
M = 0.45 mm
N = 5.12 + (0.45 – 0.35) = 5.22 mm, so we need a valve lifter 5.22 mm (0.2055 in).

Vehicle applications

Author: Sergei Wers
About: Co-founder and CEO of a multi-brand auto repair shop (engine repair, chassis repair, body repair and painting) for over 15 years. I have been developing internet sites with technical specifications for more than seven years.