I have a 2005 Expedition 116000 miles, replaced the oli cooler, welded both ends of EGR cooler, STC upgrade, Updated oil plugs and stand pipes, Turbo supply and drain upgrade. Oil changed to full synthetic, Coolant change with Ford Gold. Pypass filtration and coolant filtration. Two new AGM batteries. All of this was done two days ago, added the coolant today and started it up. Prior to these upgrades the engine started quickly and ran very well. Initially I had to crank it for about three minutes before it fired up. After engine was running I was standing in front of truck and A high pitch grinding noise started not really loud but definately noticable. I shut it down and started looking around but did not find anything wrong. Fired it up again and had to crank it for at least 30 seconds before it fired up. Sound returned in a minute or so. Let ir run for about two minutes sounds like it is coming from the turbo, looking around I notice a slow oil leak at the plate that oil cooler housing bolts to. Oil pressure gauge showed oil pressure while running. When I was installing the parts, everything went together well. I had not had any issues with the way it ran prior to the upgrades. My questions are could the small oil leak be responsible for the difficulty starting? Is there a way to tell if the turbo is bad with out having to pull it off of the engine? Any advice or guidance would be greatly appreciated.