Toyota 1NZ-FE/FXE Engine

1. Specifications
2. Overview, problems
3. Performance tuning

Toyota 1NZ engine specs

Toyota 1NZ-FE engine reliability, problems and repair

The NZ engines were introduced in 1999. They were designed specially for small class vehicles. The NZ consists of only two motors: a 1.5-liter 1NZ and a 1.3-liter 2NZ. The engine is designated for 5A-FE replacing. In contrast to its predecessor, a light aluminium cylinder block, a brand new crankshaft, pistons, connecting rods and others were used here.
While making all that, a cylinder head with a VVTi variable valve timing system was run on the inlet camshaft. Since 2004 the 1NZ hydraulic lifters have started to be assembled. It was necessary to adjust the valves at all the previous motors each 12,000 miles (20,000 km) of mileage. The 5A engine was fitted with a timing belt. The 1NZ engine has got a single-row timing chain with a 8-mm pitch of chain. In general, the engine is more like Toyota ZZ models.
Nowadays the 1NZs are still being produced. While assembling the 1NZs, its successor 2NR, 5NR and 7NR have been designed since 2010.

Toyota 1NZ engine modifications and differences

1. The 1NZ-FE model (2000 – present) is a basic motor. It has 10.5 compression ratio, 109 HP power at 6,000 rpm, and a torque of 141 Nm (103 lb•ft) at 4,200 rpm.
2. The 1NZ-FXE model (1997 – present) is a type designated for hybrid engine automobiles. It works by Atkinson cycle with a little bit delayed inlet valve closure. Compression ratio is increased to 13, power is 76 HP at 5,000 rpm, and a torque is 115 Nm (85 lb•ft) at 4,000 rpm. An updated model possesses a compression ratio of 13.4 and a capacity of 74 HP at 4,800 rpm with a torque of 111 Nm (82 lb•ft) at 3,600–4,400 rpm.

Toyota 1NZ common problems

1. High oil consumption. After running more than 100,000 miles (150,000 km) of mileage, 1NZ engines can start excessively consuming oil. If that happens, you need to replace valve stem seals and piston rings.
2. 1NZ knocking noise. It is also typical of the 1ZZ motor. If any, your timing chain has been strained. That is common with engines running more than 100,000 – 150,000 miles (150,000 – 200,000 km) of mileage. In order to handle the problem, you must get a new timing chain. One also should inspect the timing chain tensioner.
3. Rugh idling. If any, the problem can be solved by cleaning a throttle body unit and idle control valve.
4. Engine whistle. It is induced by a worn-out 1NZ alternator belt. You should check it.
5. The 1NZ’s vibration. You should check engine mounts, especially the anterior one. If everything is alright, clean injectors and replace the fuel filter. That will help to eliminate vibrations.
Apart from the above-mentioned things, the oil pressure switch is frequently disarranged, and the rear crankshaft oil seal leaks time after time. The cylinder block can’t be repaired. So, after running 150,000 miles (200,000 km), you will probably have to purchase a new 1NZFE engine.
Protecting yourself from all these troubles is easy as a piece of cake. You should use a high quality engine oil suggested by a manufacturer and do a regular maintenance of your 1NZ.

Location of the 1NZ-FE serial number

You can find the engine’s serial number on its front part under the intake manifold. The 3rd and 4th cylinders are located there.

Toyota 1NZ engine tuning

1NZ-FE Turbo. 1NZ-FTE. NA Tuning

A TRD turbokit for 1NZ is up for grabs. It will allow significantly increasing the stock engine’s capacity. You can assemble such a kit on your own. You should only get an IHI RHF4 turbocharger or something like that. It is also needed to get a turbo manifold, pipes, intercooler, blow-off, thick cylinder head gasket, 2ZZ-GE injectors, 1JZ-GTE fuel pump, and ECU 1NZ-FET/GReddy e-Manage Ultimate. At 9 psi (0.6 bar) boost pressure your motor shows about 150-160 horsepower.
If it’s needed to intensify capacity, you must get forged pistons, connecting rods and lots of other aftermarket parts. In any case, a 1.5-liter engine is not at all designed for setting records.
Besides, one can perform NA tuning, get performance camshafts (JUN), springs, valves, cold air intake, do port and polish, replace the intake manifold, throttle body, purchase a 4-2-1 header, and adjust the ECU. These upgrades help us intensify maximal engine rpm and reach higher rate of capacity.

1NZ-FE Supercharger

Like in a turbocharger case, you will be able to get some supercharger kits for NZ engines assembled by such leading companies as Blitz, Greddy, Jimze an so on. The most popular and cheapest Blitz is bolt on the stock internals and develops about 150 horsepower at 7 psi (0.5 bar). If these things are added with forged pistons fitted to a compression rate of 9 and JUN camshafts (duration 264 deg, lift 9.5 mm), the engine will be greatly renovated and you can boost its capacity to a maximal degree.

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