What is this sensor for? Yesterday I took it apart, and found there is a small hexagon plastic head inside the aluminum shell. Is it gonna cause any problem if I forgot how many turns I rotate the hexagon before putting it back?

 

i think it is the IAC

Idle Air Control valve.

i heard you shouldn't play with it. i have and it has not had any side effects yet. it adjusts the idle speed.

jason

 

when I took IAC off, I found it has some carbon deposit inside, and cleaned it. it helps also. but I don't know what will be bad if I forgot the original position of the hexagon inside it.

 

you should be able to get close enuff by turning it and monitoring your rpm's while the car is in park.

should be quite easy.

js

 

I took that off a while ago, and the hexagon turned quite a bit, but I put it back in and it ran fine. It is the idle control valve, and without it on it will not run(I tried it).

 

Is there a way to clean that without taking it apart?

I really wanted to do the IAC when I cleaned my throttle body a couple of months ago, but I just decided to leave it alone, fearing I would have to buy a gasket for it if i took it apart.

When you guys took it apart, did you replace the gasket or just reused the old one.

 

I re-used the old one, as long as you don't knick it or peel it when it comes off, it will seal fine. I know mine doesn't leak.