225,000k on odometer 4.6 V8 - when cold the car runs fine, sounds great - after you drive it for 20 minutes and it warms up it develops a rattle in the engine - sounds like under the valve covers at takeoff and low speed - driving through a parking lot type of speed. I've replaced all the coil packs and spark plugs last year and the fuel injectors and fuel filter today thinking that might be the issue. No check engine light - the problem still exists. I'm lost and need help - any...

05 GT - Engine rattle when hot