I’m sure it is a heat issue. My xbox360 still freezes up, but with the intercooler installed it will play much longer than without. Without the intercooler the 360 dies within 5 minutes of startup, with it installed it will work for about 15 minutes before the freeze happens.
So now I just have to wait for MS Xbox support to get back to me. I emailed them Monday night, so last night was 24 hours and they were supposed to get back by then, but there’s the whole xbox live maintenance downtime happening right now. So I figure they might have their hands full at the moment.