The crop needs to be "judged" in the morning to determine whether or not it is actually "impacted" or going "sour". Crops can feel funky all day long on many babies. So tonight, take away the food for the entire night. They will make it thru the night with no food. First thing in the morning, feel everybodies crop. A normal crop will be completely empty. If there is a hard lump in the crop, then it is indeed impacted. If it is soft and squishy, then it is on it's way to being sour.
Oil is ONLY given to an impacted crop. It helps dissolve hard substances. It is NOT good for a soured crop, as it is hard to break down in itself and will slow the stomach down, thus slowing the emptying of the crop, which is what generally happens with a soured crop.
Do not feed them anything but chick starter. If you suspect they are eating their bedding, (wood shavings...and mine must have eaten an entire bag full, LOL) switch them over to grass hay or a wire floor.
If the crop is squishy and soft, then add 3 tablespoons of raw unfiltered apple cider vinegar to a gallon of water. This will keep yeast/fungus from growing in the crop. You can also add probiotics, human grade will work if you don't have pet probios, and this will also help with the good bacteria's in the crop.
Sometimes babies stuff themselves with food til the crop is ready to burst. If this is the case, you can take away the food for an hour, replace it for 15 mins and then remove it again. You can also remove the food over night.
So check first thing tomorrow morning and do not leave food out tonight and see then how the crops feel. Check the food to poop ratio. It should be coming out as fast as it is going in.
Keep us posted!