2016 Tacoma 4 x 4 rough idle.

My truck idles at 600 rpm. When braking it will dip slightly below 500 then back up. Idle seems slightly rough. This happens after vehicle is warm. A/C and defrost is off. Took it in to the dealer and the service department says this is normal. I have just under 31k miles. Anybody else with issues ?

 

Maybe try going to a different dealer.

 

Mine has the heartbeat when idling but only if the AC is on. It's just the compressor cycling. If I turn off the AC it idles smooth.

 

A lot of vehicles do that.

 

I found this thread while searching for erratic idle. Did the op ever find a fix? I have a 2017 4 cyl 4x4 5 speed that does the same thing. While coming to a stop, clutch in, idle will swing down to 500 rpm, then swing up to around 900, then settle down. I've experimented a little. It does this when engine is warm, with a/c off, lights off, steering wheel not turned. I'm only concerned because truck feels like it's going to stall before it catches itself. Some sensor must be telling the Ecu to do this....going to try and make a video to take to dealer...

Thanks

 

The brake booster also causes it to drop in RPM at idle due to vacuum use. That’s normal, my truck does that. A lot of cars do that. It actually raises the RPM sometimes when you press the brake at idle.

 

Thanks, glad to hear from another member with a manual transmission. Most post are dealing with a/t issues that may be causing idle issues. My rpm does rise when I turn the wheel and/or turn on a/c. It's the dip to 500 that's weird