Bought this car and was wondering wtf was wrong with it, let me explain..... low mileage 5.0. when i started it for the first time in a few years, itfired up just fine, after it sat overnight and i tried to start it it made sounds,,,, like loose rocker arms and no compression, so after i cranked on it awile, it built oil pressure and ran fine, holds really good oil press and runs like a top, with no noise, but if it sits a day or so, same thing happens, its like the lifters are colapsing, then they build up and start opening the valves and it comes to life, but wtf? any sugestions?