I have a 99 suburban with start-up trouble

What is your question?

I have a 99 Chevy suburban k2500 5.7 liter 350. Sometimes, not always, when I'm going to start it won't turn over, instead it makes a singular loud sound until I let off of the ignition. It's a completely different sound then when it it turning the engine over

How long has your 1999 Chevrolet K2500 Suburban had this problem?

About a month