true or false

[hisel]

some one told me we must off air cond and radio first before start the engine, and must wait few second before we start the engine. the question now. what happen if i start the engine without those thing

 

[mizhan]

i'm certain there cud be possible benefits, albeit minute. i never turn off the aircond when i start/turn off my cars; no related problem in years.

 

[jarance]

No need to off air con. The E46 aircon control very smart one..

When you turn your ignition key to "ON" (just before cranking), you will observed that the FAN speed bar is shown to be setting as your previous setting.

When you crank the engine, observe the FAN speed bar..
When the engie is running, observe the FAN speed bar..

 

[astroboy]

1. Off radio and aircond to start car, this will focus the battery's output solely to the starter for cranking. Radio is not too power hungry unless u have amps. Aircond blower fan draws lots of current, so it will starve your battery leaving not much for cranking your starter. Practice those will help preserve your battery longer. That's why some people say their battery can last 12 months while mine can last at least 36 months. Of course, there are other reasons, another topic for another day.

But I think not applicable to the newer BMW as pointed out by Jarance.

2. Turn the key to "ON" for a while before cranking the engine. This is a good practice to wait for sensors initialization and also allow time for fuel to build up at the fuel rail before cranking. More relevant to fuel injection engine. Proton engine idle valve can easily be damaged if one does not wait and that's when u feel erratic idling in a Proton if this procedure is not practiced by the owner for quite some time.

Again, Japanese cars are all vulnerable to this, maybe not BMW..