I just got a 07.5 duramax it has 175000 ish on it,does not want to hold good oil pressure would stay right below the 30 mark on the gauge all the time unless you just started it then it is higher. When i would come to a stop and start to accelerate the low pressure light would come on for a brief second then go off the gauge wouldn't move at all. The turbo then started to make a bad wining noise that went away after it would build about 7 or so pounds of boost. Started home with it after he gave me a 24 month warrenty, made it 400 mile stoped to get fuel started the truck up and it wouldn't hold any oil prussure at idle but it would if you reved it up then i heard a loud noise from the turbo like a churp so i turned the engine off and pulled the mouthpiece to the turbo off and turbo shaft had a lot of play,and i mean a lot. Had it towed to a diesel shop. If the turbo is bad would it be part of the low oil pressure problem at idle? It also lost some of its coolent the tank was almost empty! Any thoughts any one?