Engine makes a "loping" sound at idle

[tank_7]

Curious if someone else has had a similar issue like this. It's a coworkers 4runner and she has been having some problems over the last couple of days. At idle it's making this loping sound as heard in the video. I was thinking harmonic balance or like a CAS or something. But I'm not really a technical mechanic.

Sorry I'm at work so I'll get back on here with more info later. Any ideas would be much appreciated.

 

[tank_7]

Also, theres no CEL. Which is weird.

 

[StreetCreeper]

I had a similar issue with my truck. While not quite as pronounced as in your video, it still pulsed and would dim the lights as I drove or idled. In my case it turned out to be a bad voltage regulator in the alternator. While that may or may not be the case for you, I would suggest checking for vacuum leaks as a good place to start. Also check the ground and power cables from the battery/alternator and make sure they are clean and tight.

Oh and I never had a cel light either.