A/C Pushing me forward?

today I noticed my truck pulls forward (and backwards) if I turn on the a/c while i'm stopped.

I know my rpms would go up a bit (about 150-200) but I haven't ever noticed it pulling more.

I tested this out on a flat driveway, and I would pull forward without the a/c on, but with the a/c on I got a bit more speed.

Anything to be worried about?

 

Ac puts more load on the engine, so maybe the truck revs a little more to compensate, mine does it too. Never tested the pulling forward thing, makes sense if the rpms are hogher

 

Seems like it should rev more, but only to compensate. Just enough to make up for the used power by the compressor. Oh well.

 

Completely normal. It's just your compressor kicking on and off to maintain refrigerant pressure with the AC running, and the ECU/engine working to compensate the extra load placed on the engine when the compressor needs to run.

Others here may be able to define the mechanics of all of this more precisely than me, but you have nothing to worry about. Everything is working as intended.

 

Mine did it over the weekend while waiting to take my turn over an obstacle. Completely normal.

 

FYI , the AC compressor cycles when either defrost setting is selected and it will happen in winter too

 

...what's AC?

Just kidding. But that's normal. And as oz said, it happens with the defroster too. Ask me how I know...