I have resolved TWO problems that seem to be common with early 2000's suburbans, tahoes, and silverados, and all you will spend is $12 or less. FIRST, the knocking noises heard when starting up the 5.3 liter engines can be eliminated by using a oil filter that has a check valve built in. I put a Bosch filter, about $12, into my '01 suburban. It keeps the oil up in the engine where it needs to be at startup. Knocking since new, the noise is virtually gone at startup on an engine with 230K on it. The check valve is not 100% though, and if the vehicle sits for more than a few days the oil does slowly leak back into the pan and the knocking returns. But if you drive it today you will notice the lack of knocking tomorrow when you start it. AC Delco makes one also, for about $4, but I have not tried it. SECOND, the knocking noise you can hear AND feel in the steering wheel when making a turn. Many an intermediate steering shaft have been replaced for big bucks when the problem can be fixed with a $4 can of silicon spray. Under the dash where the steering wheel attaches to the steering shaft is a yoke-like connection. I wiped the dust from it 2 years ago, gave it a spray, and the knocking has been gone since! I went from thinking the suspension was going to fall apart underneath me to not a sound with a couple squirts of silicon.