My Atlas 2-6-0 Northern Pacific mogul does not appear to be running very well on my Atlas code 55 track. It is extremely noisy, sounding as if it is hitting the ties, and pushing the cars (with low profile wheels that I installed) on the track by themselves yields a totally smooth noise free experience. Pushing the engine over the track feels very bumpy as if it is in fact hitting the ties and the larger wheels are definitely taller than my low profile wheeled cars. Is this expected? Are there any engines with smaller profile wheels? It's a bit disappointing as this is the perfect engine for the project my brother and I are working on but we must have a good running train of course. Any insight to this is greatly appreciated!