2003 chevy avalanche starts up but dies when you put it into gear and press gas

SOURCE: 94 chevy suburban revs up and down, then dies

timing chain

SOURCE: chevy avalanche transmission problems

Hello;
Are you getting the check engine light? If so the electronics may have gone out. You may not need a rebuild but you won't know till you pull the oil pan on the transmission and inspect the contents. You may also have lost the neutral safety switch. It is mounted on the drivers side of the transmission. Check those out first and let me know what codes you get.
For Ponchoboy; the clunking and hissing you hear are teminal root causes. Drop the oil pan and if it has a lot of filings and metal it is time for a rebuild.
Hope this helps; Rate me highly;
Rich
RPM Northwest

SOURCE: 2003 CHEVY AVALANCHE dash board telling me left

check the lil switch that'll be located on the latch anchor point or within a few inches of it.... odd is the switch is faulty

SOURCE: 89 chevy celebrity dies when put in gear

get your fuel filters and cataltic converter checked

Testimonial: "thanks very helpful!!"

SOURCE: Where is oil sending unit on 2003 Chevy Avalanche

It's at the very back of the block, top-center, under the intake manifold.