[brucehandley]

i've run turbo skymasters for 20 years. living in colorado the turbos get used! the wastegate controllers tend to coke up when the shafts wear. with 3000 hours i would bet the shats are worn. you can use a copper based lubricant periodically or have the wastegate overhauled($s). i also have had problems with the turbo controller, it seems a lot of shops don't know how to correctly overhaul them. eventually i found someone at firewall forward in ft collins, co that knows what they are doing. what i have noticed over the years is that shops in the mountain areas know a lot about turbos and oxygen systems because a lot of aircraft have them. sea level shops just haven't seen that many. as far as induction leaks, i had a rubber coupler come completely loose and still got near full boost at 7000 feet. the turbos are a bit overdesigned.