Originally Posted by nakman
is it really the battery? Pretty common to hear a hissing from the charcoal canister.. which is near the battery obviously.
In the 4Runner it could be the brake accumulator but that is more of a buzzing sound and is closer to the back of the engine bay. I put my ear fairly close to the battery and the sound appeared to be coming from that positive-side vent.
Originally Posted by AShoe
Does it stink? Check the voltage across the battery while the truck is running. Venting gas can be a sign of overcharging. A strong sulfur smell is a sure sign of overcharging.
Didn't notice a smell and didn't notice anything visually (any kind of colored smoke). I don't have a voltage meter because I am an electrical idiot
Worst case, if the battery is indeed overcharging, is it safe to hook the battery back up and run it to check the voltage? Am I correct in assuming that an overcharged battery will mean I need to plan on a new primary battery this week.