Can you track an iPhone with no SIM card in it?

No it is only traceable if a text is sent which will then give the police your position. If the phone has no Sim the phone is void, empty as such, which means it still can be operated but without a Sim card you cannot access the Internet, call, text, or anything along the Wifi range. It's only traceable with the Sim card inside. Yes, the phone has a serial number on the inside of the phone, but that will not give locations; it will only say where and what date it was made.