So, My wonderful Silverado has the 5.3L Vortec and the 4L60E transmission and is sitting at 210,000 miles. What has been done (realted to major expenses): The transmission was rebuilt 12 months ago ($3k) and still has 2 years left of a 3 year warrenty. What is happening: I am putting about 1 quart of oil in it each week to top it off. The knock sensors need to be replaced (Throwing the check engine light) Options I am considering: (Cheap) Keep putting a quart of oil in a week to top it off and run it into the ground at some point in the future till the engine officially dies. (Next more expensive) have the valve cover gaskets, header gaskets, and the oil pan gaskets replaced, and have the knock sensors replaced at the same time (Approx $1000 investment). (Next more expensive) Get a stock crate 5.3L and have it installed ($2500-$3000), but this will be an engine with no miles and a full warrenty. (Next more expensive) Have my 5.3 torn down, bored out to a 5.7 and rebuilt replacing all the parts and upgrading the cam, and some other parts to push an extra 200HP and have a full warrenty. ($5500) and rent a car for 1-2 weeks. (Next more expensive) Buy a new or slightly used (1-3 year old) "New" Silverado. Take my current truck, pull the tags, and insurance and garage it till I can actually work on it while driving the new truck and upgrade the **** out of the old one. Other issues: The truck is 12 years old, its got a good bit of body work that needs to be done, inside, the carpet needs to be replaced, etc (Its not a "new" truck) Worst case, I would get into a truck payment that I don't want on a truck that is either new, or a few years old. Other than the oil leak and the milage, the engine cranks and sounds like the day it was purchased. What would you do?