My dodge journey check engine light is on and my temp..gauge is going to hot then cold

Hello, first it's best to check to see what is causing the check engine light to come on. A diagnostic tool capable of determining what trouble codes are stored and then monitoring related components -- such as engine temperature -- is important to have as a resource to find out what is going on. Reach out to some local technicians near you to find out what's going on: www.repairpal.com/repair-shops