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??

Yeah, I'll trade ya my working 180 for that one so I can run cooler.

It should be fine. Better than stuck closed!! hehehe

seems to me engines that run cold like that tend to burn oil. Atleast the 350 in my grandpas river boat will, he usually gets little pebles stuck in the thermo, when its running around 100 degres, it goes through oil.

I'll keep a closer eye on the oil until I have to swap it out for a working 180 degree stat.

You'll be ok for a short while but will throw the ses code for not warming up.
Have a good trip and check the oil often.