One problem related to engine clicking and tapping noises has been reported for the 2006 Chevrolet Trailblazer. The most recently reported issues are listed below.
Was driving down a hill and started hearing a loud clanking noise. Had check the oil the day before and was right where it was suppose to be. Pulled over when we heard the noise and checked the oil and was completely bone dry and had to add 7 quarts. Got about 10 miles and the car completely shut off. Mechanic had checked what was wrong and it had thrown a piston rod.