The new thermostat on my 99 is stuck open (only 2,000 miles old, but we won't get into that right now...I'll save that for AutoZone!!!). Anyway, other than getting poor gas mileage and no heat (not that I need it in the summer), will I do any damage by not changing it out immediately? I have a long trip this weekend (700 miles) and I don't have time to change it before I leave. I don't mind the depleated gas mileage, but I don't want to do any damage to the engine or PCM. It'* only heating up to 125 degrees or so. Thoughts??