I recently bought a large scale Christmas train for my 6yr old son and I to enjoy. This is our first train. Assembly went well and the train has been operating fine until last night when I started to hear a squeaking noise coming from the front car - possibly the wheel? Unsure what to do at this point. The track is on the ground and we have been running the train for about 30 mins to an hour for about 3 days. Any suggestions are appreciated!