My family car is an Alza. I drive it weekends to fetch whole family of 3 generations to meals and shopping. My Parents + my sister + my son... It's a great economical car... trust me, it is very valued for money.
However, I realized driving on hot weather, aircon is not as cold and the engine is sluggish. A little peek under the hood, the answer was revealed.
The Air box intake pipe is in the engine compartment and it is sucking hot air from inside the engine bay. I guess this design is from Japan where during winter, it is taking warm air to prevent throttle body from freezing.
Also realised that the Aircon piping are HOT on both the H and L pipings as soon as I cut off the engine for around 5mins.
Checking my garage, I found this piece of heat shield I took out from my EvoX's Open Pod Heat Shield project. It's a industrial plastic material used widely for advertisement boards. It resist heat well and will not melt easily. (It survived 3 months in a Turbocharged engine)
Here's the picture of the heat shield in place. Just slot it in after you cut it to shape. I was very lucky as it is the same shape as the design I traced out for my EvoX project, only thing is in the Alza, I only use exactly half of it.
Do ensure that the heat shield had some curved front part towards the grill to help scoop cold air into the intake compartment.
Cable tie it to keep it in place... However I find it already fitting tightly and perfectly.
A closer look. The heat shield nicely compartmentalize the hot area from the Intake area and the Air Con piping. The intake pipe will only be sucking in cold air and fresh from this part of the engine bay
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Did a 30 KM drive after this DIY. The difference is felt by everyone in the car. Car accelerated smoother and easier after traffic light stops. Air Con cools down faster and have to turn the thermostat down a little...
Raya is coming and many will be traveling and traffic jams will be unavoidable. Try this little DIY that will give you and your family a more comfortable traveling experience (also to give a little power to your car instead of sucking hot air)