Well since I'm the "mechanic" in my family, that means I get to wrench on the Malibu my parents just bought my 17 year old sister. It's her first car and even though it may have came a year late, it was for good reason. My parents are very protective and my sister isn't the greatest driver. Anyway, it's a 2001 with 145,000 miles and a little rough around the edges, but overall a nice, good running car.
First order of business was the temperature/thermostat situation. The temperature needle was pegged at 100*, the heater never warmed up, the idle was at 1500rpm, a fan was always on, and it was throwing a code for low temp. So I check out what's going on under the hood and see a big glob of silicone on the lower intake manifold where the thermostat housing bolts up. Great!
Pull the glob off and it's missing a big chunk of aluminum.
Guess this explains the low temperature.
The top bolt actually grabbed enough for me to tighten the housing down. I still used a little RTV just to cautious. I then globbed some JB Weld over top the exposed bolt threads. I figure it will hold for a while or until it comes time for a LIM gasket job.