4Runner Overheating Active Air Flap

Sounds familiar! I had a similar issue with my 4Runner. Is the engine temp spiking quickly, especially at lower speeds or when idling? And are you noticing any weird noises from the front of the engine bay before the overheating starts?

Yep, exactly that! The temp gauge climbs fast when I'm stuck in traffic. No weird noises that I've noticed, though. Did you figure out what the culprit was in your case?

Okay, sounds like the same gremlin I fought. Pretty sure it's the electromechanism on the active air flap. Best to get it checked out, as it could cause serious damage if it gets too hot. I ended up at a workshop and they confirmed my fears.

Thanks a bunch for the insight! I was dreading that it was something major, but at least now I have a direction to point the mechanics in. I got the bill: 590€ to replace the defective electromechanism. I really appreciate the help!