Ask the mechanic: Can I replace my old Premio Super with a Sienta?

Hello Paul, I have owned a used Toyota Premio Super 2000 for the last five years and it has been okay. However, lately, I am frequenting the garage because of constant breakdowns. Recently, the mechanic told me that the filter for the hydraulic fluid got damaged because the hydraulic was leaking. I want to get rid of the car and buy a Toyota Sienta since I have a small family. Please advise on its durability, maintenance or if it has problems with the gearbox or engine. Peter N

Hello Peter,

The leak in your Premio’s gearbox was most likely caused by a failing transmission pan seal. May I hasten to add that a full automatic gearbox service at 100,000kms ought to consider replacement of the gearbox filter and pan gasket as well as a suitable transmission fluid such as Toyota TIV or Dexron III fully synthethic gearbox oil. An attempt to cut costs during this service leads to the problems you are experiencing. 

The Toyota Sienta mini passenger van has a smaller and fuel-efficient 1NZ-FE 1.5 litre engine which will give you about 16 kilometres per litre of petrol on the highway and about 10-12 kilometres per litre in city traffic, depending on how you drive, the load and traffic jam. The Sienta engine has sufficient power (109 horsepower) to carry up to five passengers or light cargo suitable for your small family. 

The Sienta’s cuboid-shaped long, wide and high roof design provides ample passenger legroom, shoulder and headroom. There is also impressive cargo room when you drop the middle seats. Its cube-shaped body is not very aero dynamic whicch has an impact on fuel economy. The small 1.5 litre VVTi engine works well with the CVT (Continuous Velocity Transmission) gearbox to deliver the above impressive fuel economy. 

However, the 1NZFE engine’s timing chain kit and variable valve timing systems are sensitive to oil quality. It is prudent to use recommended fully synthetic 5W30 engine oil or the semi synthetic 5W30 or 10W40 when the engine ages. The continuous velocity automatic Transmission, which improves fuel efficiency of the Sienta, uses specific CVT service fluid. To avoid breakdown of this gearbox, service it with approved fully synthetic CVT oil as soon as you acquire the car. This will prevent costly damage and maintain fuel efficiency. If you maintain the Sienta well, it will give you better reliability and less running costs such as fuel.

Can I replace my Vitz 1.0 litre engine with a 1.5 litre?

I drive a 1000cc vitz 2007, which lacks power while going uphill. I am contemplating buying a new engine with more horsepower (1.5cc). What could be the issue? Cornelius

Hello Cornelius, I understand your frustration with the low power and acceleration of the Toyota 1KRFE 3 cylinder 1.0 Litre engine. This 1.0 litre engine only delivers 49 kilowatts or 66 horsepower compared to the Toyota 1NZFE 1.5 Litre engine’s better 81 kilowatts or 109 horsepower. 

A swap or migration of engines from the 1.0 litre to 1.5 litre will only reduce your fuel economy slightly as well as slightly increase your maintenance cost. Overall, the 1.5 litre engine will be efficient, more reliable and long lasting as it is not over strained as the smaller three-cylinder 1.0 litre engine. 

The only catch is the need to buy a 1.5L engine and corresponding gearbox for this migration. You will need to replace the engine computer and wire harness to suit the four-cylinder 1NZFE 1.5 litre engine. The four-cylinder engine exhaust manifold will also have to be found to replace the three-cylinder one. Corresponding engine mountings also ought to be found and fitted to the frame by a good welder. If you find the conversion process tedious and costly it might be less of a hassle to sell your 1.0 litre Votz and buy a 1.5 litre.