Bought a used 159 limited edition 9 months ago, high mileage so expected some issues. Generally runs well, especially when cold, but as it warms up (after about 8 - 10 miles) two problems appear:
1. Noticeable chassis creak in background, not necessarily worse over bumps but when you pull up and pull away you get a low frequency 'creak'. When stopped, you can recreate it by pushing down on the front right panel. Local garage dismantled the front right suspension fully but couldn't see or hear any problem. It may be in that general area but perhaps not the suspension itself. Any thoughts, could it be linked to steering system?
2. When cold, turbo works fine through full range. When warm, as you accelerate through 2nd/3rd gear and above at times, not flooring it, the mid range (about 0.8 - 1.0 bar) sees the turbo pressure 'wobble' and you get get interruption of acceleration. There is an accompanying noise which is hard to describe, sounds like a rasping noise. At lower and higher turbo pressures, you don't see this at all. If you drive it like a lunatic you don't use this mid range for long so you don't see it, but you'd get 12 mpg!! Forums indcated MAP sensor so I have cleaned that thoroughly without success. Also used two tanks with additive to clean up the general system, no change. Garage indicated maybe intercooler pipes might be softening and need replacement, meaning they are squashing at these turbo pressures and then releasing? Again, any thoughts?
Hope someone can help, these are notshow stoppers but really irritating. Can't afford to throw speculative money at these without an idea of cause.