Ask the mechanic: What is wrong with my car AC?

Hi Paul, my Toyota Klugger has a peculiar airconditioning fault. Whereas the mobile AC technician has refilled it with gas two times within three months, it blows small amounts of cold air. The technician says the fans work well and there is no leakage of gas. My AC technician has run out of ideas. What could be the problem? Susan.

Hello Susan, from what you describe your air conditioning (AC) system may need an AC cabin filter replacement.
This filter is positioned between the AC blower and the air vents. When the cabin filter gets clogged with dust it tends to restrict cold air delivery to the vents. This filter ought to be inspected after every four engine services and replaced when it is found to be clogged with dust. In less dusty conditions the AC cabin filter can be used longer.

Hi Paul, I drive a Toyota Vista but there is a light showing ABS on the dash board in the last two days. What does that mean? Any danger on my car? Thanks.

Hello, the ABS light on your dash board stands for the Anti locking brake system which is designed to safely stop the car without skidding when you brake the car suddenly. This system is both hydro mechanical and electrical. ABS computor relies on wheel fitted sensors to monitor the speed of each wheel and communicate to the engine and transmission computors. A break down of the ABS system or an interruption of its power supply will cause the fault light to show.
This will not prevent normal hydro mechanical brake performance which enables you to drive the car to your nearest garage.
Occasionally a faulty ABS system can cause unexpected judder under the brake pedal which may compromise your car’s braking performance and safety. You ought to find a repair technician with a computor diagnostic tool to confirm whether the ABS unit, its relay or sensors are faulty.

Hi Paul, I drive a Toyota spacio 2004. Lately I have been noticing some puffs of white smoke coming from the exhaust especially when the rpms goes above 3,000. I read online that the most common cause of this could be a blown head gasket. Is this true and what’s the cost and lately impact of changing the gasket. Kind regards. Solomon

Solomon, white smoke from a car exhaust pipe is usually due to infiltration of engine coolant in the
combustion chamber where it gets burnt with the fuel air mixture. What you read is right, the common cause of this symptom is a damaged cylinder head gasket.
However it can also be a result of a damaged engine block or cylinder head which allow coolant to leak from its designated passages to the combustion chamber. It should be noted that sometimes small amounts of white smoke can be seen after a cold start in the morning.
A good engine mechanic should observe how much smoke is produced before dismantling to inspect the engine and confirm which of the above factors are responsible. This inspection should advise what parts need to be replaced and the cost. You ought to buy genuine Toyota parts for the delicate repair job.

Hi Paul, my vehicle is a Toyota Kluger. I replaced a tyre but as I was driving home ABS and foot brake lights started showing non stop. What could be the problem? Samuel.

Samuel, during the replacement of that tyre you need to establish that the ABS (Anti Lock Brake system) sensor was not dislodged or damaged. Another possible explanation could be that the spare wheel you fitted was not the same size as the ones on the car.
If this is the case then the ABS system will report a fault because the smaller or bigger tyre circumference will make the spare tyre move faster or slower than the other tyres. This triggers an ABS fault because the ABS computor is receiving conflicting speed readings.

Ask the mechanic
By Paul Kaganzi
0772316145
send sms: mycar (space) your comments and questions to 6933, or email them to [email protected]