Hey, don't know if any of you have experienced this, tried searching but didn't found anything related. My car starts normal, with a pretty good idle. It warms up like allways. When I turn on the radio (with factory sub) and/or headlights the idle stays normal (700-800rpm). Everything's ok up to the moment when I turn on the a/c, the idle lowers suddenly and won't stabilized, the engine shakes a little but not much. This will happen like 95% of the times I turn on the car, it doesn't matter if it's the first time in the day or the tenth time; and it goes away in like 5 to 10min. I know it's not the a/c gas because it doesn't have any problem cooling at our every day temp of 90deg. I'm thinking maybe its electrical. Any help will be appreciated...

 

i think that happens to everyone?

 

So you have a unusual idle during this entire time frame?...What does it idle at when vibrations occur?

The a/c will usually drop my idle momentarily but it returns back to normal. I get subtle vibrations but it only lasts 1-2 seconds.

 

When I turn the a/c on it will idle around 500rpm and yes, it will do it for 5 to ten min.
I will take the car of the garage, run to the first stop light and it will continue. It will stop if I turn the a/c off or after a little while. Don't really think it's normal.

 

a/c running the compressor off of the engine's power.....

of course it's gonna affect it.

 

Sounds like the compressor is boggin it down waaaay too long though.

 

mine does it the whole time...

 

Mine makes a grumpy sound when i turn the a/c on when i turn the a/c on right after starting the motor. But it doesnt last any amount of time. Its an instant...GRUURP sound. But yours sounds kinda serious. Take it to the dealer. 5 to ten minutes of shaking???? Not normal guys.

 

Mine does it at stop lights when it is idling.

If you think the tC is bad......my Yaris with the GReddy exhaust is even worse....it is normal.The compressor is using motor power to run,AC compressors do not pull power evenly......as the head in the compressor builds pressure and cools the gas it open and closes the valve and that is what makes them run like that.

Get the compressor checked to make sure it is not failing......they do fail and can make the car idle really weird,but your description sound like normal operation.If you have an aftermarket exhaust you will really notice the rise and fall of the idle even more than you would with a stock exhaust.

 

I really noticed it when the exhaust was put on the car like BZinn1 said. If I recall my rpms chill at like 500 or so with the a/c on and never really exactly stabilizes. I'll have to take notice next I use the A/C.

 

Agreed. Unless your engine suddenly dies when you introduce the added draw of the A/C compressor...I wouldn't worry about it.

 

Are we talking about a cold start? If so, 5-10 minutes of idling at strange RPMs is completely normal; the engine's trying to warm itself up. If there was a problem with your compressor constantly running, you would see the impact in your gas mileage.

I have never been in a car that hasn't vibrated with the A/C on, except my old Dodge truck... which CONSTANTLY vibrated, A/C or not (5.9 liter V8 ).

 

Mine does it at every stop light I stop at with the AC on........freaked me out the first time it happened.....now I just ignore it.....it happens withthe defrosters on as well as I beleive the air for them comes out the same path as the AC so it dries the windows moisture.

 

Mine stopped doing it...after the compressor went bad

 

Thanks for the feedback guys. I do have the Borla exhaust and a set of headers, maybe thats the reason. Either way as long as it cools I'll ignore the shaking.