Many Japanese kits (Tamiya, Fujimi, Hasegawa, Aoshima, etc.) do not have engines. Although there are not words on the box to say so, in most cases the box art will give you the necessary clues. If there is an image on the box side with the hood up and engine exposed, or an artists rendering showing a ghost image or cut-away image that includes an engine, there will be one in the kit. If no suggestion of an engine is seen anywhere on the box, there almost certainly will not be one in the kit. Tamiya in particular is very reliable in this regard. Their box art is very consistent.
Now, this doesn't always help when ordering online. After awhile you get a feel for what kits or types of kit will have an engine, but this takes experience. Sometimes the vendor can advise, though this isn't always helpful. Perhaps your best bet is to post a question in the Builder's Corner or other appropriate section of the forum. Someone here will know the answer and be happy to give you the 411.