Ask the Mechanic

Thursday January 28 2021
By Paul Kaganzi

Why is my heater not working?

Hello Paul, my AC works perfectly but the heater does not. What could be the cause of the breakdown?


Hello Tony, did you know that hot coolant is used to heat up your car ventilation? A breakdown of one of the ventilation heating components that help to channel this coolant around the vents can cause a no heat condition.

There are a couple of components you need an AC technician to investigate. These include a blocked heater core, bad heater control valve or a broken down air door actuator, which is ordinarily used to select cold or hot air for the ventilation system. A qualified car AC technician should know how to test the heater core unit for blockage by running water through it.

This is recommended before the decision to remove it. Removal of the AC core would require dismantling a part of your dashboard, which requires a knowledgeable technician who will be able to reassemble the different components. The car manufacturer recommended AC coolant 314a should be used after the job.


Which is better between a Premio and Spacio?

Hello Paul, I need to buy a car for my brother who is torn between a Toyota Premio and Toyota Spacio. He will sometimes need to travel with elderly people to the village. Which car should we buy?



Hello Robert, the Toyota Premio is a sedan saloon car while the Toyota Spacio is a multi-purpose vehicle (MPV). Your choice between the two will be based on their functionality and your brother’s transport needs. Let’s understand the difference between your two options.

The sedan or saloon car (Premio) is usually a two row, five passenger transporter with four doors and an extended trunk. Space for the passengers and cargo is fixed and cannot easily be adjusted. On the other hand, the MPV (Spacio) has a three row, five to seven seating capacity with the space for passengers and cargo shared interchangeable.

One can deploy seven seats to accommodate more passengers or carry one passenger and fold down the centre and rear seat rows to create extra cargo space. In fuel economy terms, the 1.8 litre engines on both options will more or less give you the same fuel efficiency and differences will be due to loading of passengers or cargo, how you drive and service condition.


The Premio saloon’s more aero dynamic structure has better driveability on the highway because of better response to dynamic and torsional road forces as well as a lower coefficient of drag during high speed driving. Premio would be a better option for a frequent highway traveller who has only three to four passengers and minimal cargo. The Spacio on the other hand is a good shuttle for children and family with shopping, parcel or cargo delivery.

My car is failing to start

Hello Paul, I have had trouble with starting my Prado petrol for about two months now. I even had the fuel pump replaced but without much change. The mechanic checked the spark plugs and some other part which he immersed in water for some time (is it solenoid? can’t remember the name) and declared it was okay. What could be the trouble? 



Hello Sam, has your technician run a computer diagnosis to check whether the engine has an electrical fault causing the cold start difficulty? There are electronic components in your Toyota engine such as the crank shaft position sensor, coolant temperature sensor or throttle position sensor that can cause starting difficulties if they are faulty.

A computer diagnosis will help to rule them out. It would be good to request your mechanic for a written defect and repair report indicating clearly what he repaired so that you are not left guessing. Repair history serves as useful case notes when following up on a persistent fault or trying to get a second opinion.

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