Heres the prob: 2002 5.3liter with 94,000 miles on it, starts fine-engine is noisy due to lack of oil lubrication on initial start up. but mine is a little extra noisy. seems to idle fine, sometimes lopes a little bit. when i give it little gas and hold it(about 800-900rpms) the engine shakes like crazy-vibrates the whole body. above 1000rpms shaking goes away. ive heard about cam lobes getting worn, but i am not sure that this is the problem. this engine has had much abuse, but always the finest maintainance(Mobile 1 full synthetic every 3000 miles religiously, fuel filter every oil change, new plugs and wires,etc).
Any help will be extremely appreciated. I would love to continue going to the track, but i do not know if i am just doing further damage to an exsisting problem.