Idling in Park

i noticed today on my lunch break in a Starbucks parking lot that, while idling in park, the truck will remain at around 1k RPMs but every fifteen or so seconds will drop 400 or so and then kinda stutter-- like it wants to stall-- but then jumps back to 1k.

i'm probably overthinking it, but every other time i've sat in a parking lot it's never done that.

AC TRD OR 4x4
the only things i've done recently are grease the U-joints and torque the U-bolts.

any ideas?

 

Ya take it back where you got it from your truck shouldn't hunt like that. Sounds like possibly your iac is having problems

 

ac compressor kicking on/off

 

thanks, dudes. i'm gonna test some things tomorrow. idling with and without A/C and i'll get a video anyway if i can.

 

Mine does the same thing when warm. Taking it to the dealer on Monday to get this checked as well as tranny fluid.

 

it's definitely the AC. with it off, it hovers around 600 RPM steady.

thank you, @127.0.0.1

 

I have same issue. Any news from your trip to the dealer?

 

It's the AirCon. I understand defrost mode forces the AC to run making the RPMs fluctuate. If you change settings/turn off the fan, mine stops fluctuating

 

Not to be confused with....