Since my Monte is being worked on by the trans guy and may be sold. I had to look at the Caddy because driving home the other day the heater didn't work. This is the second time this year. Last time I had the heater core flushed and it worked fine. So I decided I would do it this time. There is also a restriction piece in the line. One of the Cadillac sites suggested removing the whole piece. I just removed the rubber restrictor from inside of it. I ran it around the block and it seems to be heating up again. Hopefully the more flow will help keep the heater core clear of junk.