Toyota’s Japanese car engines have always been famous because they combine the use of modern technology, ease of maintenance and good performance. The first generation power unit with the 1JZ index was a six-cylinder inline engine having a volume of 2.5 liters and 3 liters. These engine are installed on the Toyota Crown, Mark II, Supra, Brevis, Chaser, Cresta, Progres, Soarer, Tourer V and Verossa.
This machine appeared in 1990 and was able to stay on the assembly line until 2007, proving that this machine is highly capable and high-tech. But the 1JZ engine also underwent some improvements: an ACIS mechanism was added which changed the intake geometry, the attachments were now on a single rivulent belt, and the oil pump was replaced with a reliable and productive version of the trochoid type.
1JZ-GTE Problems & Reliability
Despite the fact that the Toyota 1JZ engine is known for its reliability and durability, it still has some weakness. What problems usually arise and how to solve them:
- The first problems is with the valve and VVT-i clutch. The short life of these elements often results in floating speed and knocking on the engine. After replacing it, the problems disappeared.
- The engine won’t start. The reason for this problems is usually the spark plug which is flooded with oil or fuel, open the spark plug cover, take the spark plug and clean it using a dry cloth or sandpaper.
- High fuel consumption. Usually connected to the lambda probe which failed. It is advisable to replace the oxygen sensor as well as the air filter and possibly the mass air flow sensor (MAF).
- Increase in oil consumption. If the engine mileage is high, it is possible that the valve stem rings and seals will need to be replaced.
- Weak timing belt tensioner. The power source of the belt is declared by the factory at the level of 100 thousand kilometers – not bad, but because of the tensioner it can break early. Fortunately, all engines, except for the direct injection version, are “non-stick”, when the belt breaks, the piston and valve do not meet. But anyway, when the problem with the timing belt occurs because of the tensioner, it’s no fun.
- The reliability of the electronic fuel injection system in the 1JZ had a revolutionary design for its time, which made it possible to ensure the highest quality fuel combustion in a wide range of revolutions. The car reacts quickly when stepping on the gas pedal and feels dynamic.
- Apart from this reliability, it features the power unit having two camshafts which are actuated by the belt at the same time. Thus, the vibration of the engine is almost completely imperceptible, which has a positive effect on the comfort of the car equipped with this power unit.
1JZ Fuel Consumption
The engine shows acceptable fuel consumption considering its power. In the city, it takes 15 liters per 100 km, on the highway consumption is reduced to 9-10 liters per 100 km, and in a combined cycle the consumption is 12.5 liters.
1JZ Engine Maintenance
- The engine has not only impressive dynamic performance, but also excellent resource characteristics: an overhaul is required no earlier than 400,000 km. All work is carried out according to the manufacturer’s regulations and recommendations.
- The timing mechanism is driven by a belt; when the belt breaks, the valve does not bend. The life time is 80,000-100,000 km.
- Antifreeze is used as a coolant, which has to be replaced every 3 years or every 60,000km.
- The engines of the 1JZ series do not demand special spark plugs: you can install regular, platinum or iridium spark plugs. The frequency of changing candles every 20 thousand km.
- Every 100 thousand km, it is required to adjust the thermal clearance of the valve using shims.
1JZ Oil Changes Interval
The frequency of oil changes is in the region of 10,000km, for this you will need 4.2 to 5.1 liters of oil with a viscosity of 5W-30 or 5W-40.
In 2000, both engines were modified by direct fuel injection. Engineers expect the motor to be more economical while maintaining the same power. But the design with a high-pressure fuel pump has become more capricious than the basic engine, it has a strong dependence on fuel quality, access to spark plugs deteriorates, and overall reliability decreases.
Yes, fuel consumption has decreased, which users love, but tuning lovers and “racers” prefer conventional modifications because they don’t have too many problems. Btw, Nissan also has a good RB26DETT sports engine with a capacity of 280 hp, so the 1JZ is hard to compete with.