Hi all,
I thought I would take the time to update this thread with the outcome of my investigations and attempts to free the seized unit. I removed the exhaust elbow last night and took it home for a decoke with caustic soda, it was a good job I did as well, the water channels were almost completely blocked! Below is a photo of the exhaust side of the turbocharger
clearly there is a considerable buildup of carbon deposits although it doesn't look nearly as bad as the one that latestarter1 shared on the first page of this thread. I sprayed it liberally with wd40 and using a socket wrench managed to get it turning. The vanes were still 'sticking' as they rotated so I employed some brake cleaner and scrapped the worst of the carbon from the channel. The turbo now span quite well although not as smooth as the starboard turbo. I reassembled the unit today and tested her in the marina with no load, I could here the definite whistle of the turbo spinning up as I increased the revs, so took a calculated risk of sea trialling her. I'm pleased to report that the engine now revs comfortably to 3800 rpm and the boat will get on the plane. My top speed is still impacted by fouling on the hull, so I wasn't expecting miracles, suffice to say I am relieved that I don't need to spend £300-£900 on a repair
This isn't the end of my problems though, please see the next post.........