Garrett does make a good turbo, but I think Subaru's been a lifelong customer of Ishikawajima- IHI.Most (if not all) US turbos are manufactured by Garrett for many years now and they have pretty good reliability record. Most fauilures of Garrett units were due to abuse or failure to properly change oil at proper intervals with proper oil.
Looking at the sticker, engine and transmission are from Japan, then 40% of components are from Japan and 40% of components are US/Canada origin. Not excatly "knocked down kits" being imported here....That plant in Indiana is technically in Japan. Trade laws are weird. The cars produced there are complete knockdowns as far as I've read. So cars produced there actually have to be "imported" on paper and have tariffs paid before they go to the dealer.
Usually the bearings become starved for oil, start to bind, and then shed metal. Then the clearances open up due to wear and the shaft gets loose and moves radially. At that point the impeller and turbine start banging around in their housings and you get battering damage and metal shards headed into the engine and out the tailpipe.What causes that kind of damage? Heat or oil starvation?
Would a pyrometer help prevent turbo melt down?
I occasionally flew turbo charged aircraft. One of the shut down procedures was to allow the engine to idle for a minute or two before pulling the mixture.Usually the bearings become starved for oil, start to bind, and then shed metal. Then the clearances open up due to wear and the shaft gets loose and moves radially. At that point the impeller and turbine start banging around in their housings and you get battering damage and metal shards headed into the engine and out the tailpipe.
The stuff going into the engine is the biggest problem since it destroys the heads and pistons for sure, and maybe scores the cylinder walls.
Change your oil on schedule and use nothing but synthetic! Check and clean, or remove, the banjo filter!
I would put a pyrometer on a highly tuned engine just to keep track of the combustion temps, but it wouldn't have helped in this case, IMHO. Someone ignored the warning signs here and kept flogging the car after the turbo started to go! This kind of damage doesn't happen in a couple of seconds - probably it was many minutes, with really bad noises from the engine compartment and black smoke pouring out the tailpipe. If he had shut it down as soon as he saw smoke (when the seals failed) he might have saved the engine.
Here is the discussion - I didn't post a link because they don't really say much worth reading. ... I think this might be your problem, turbo out of my brothers poorly maintained Forester XT : Justrolledintotheshop
Spokane WA USA
The turbos in our cars are pretty small, and de-spool pretty quickly after last use. I don't have a turbo-timer or anything, but I often let it idle briefly before shutdown.Does anyone with a XT (or GT)let it idle a bit before shut down?
Would some sort of pressure oiler be helpful to continue to feed the turbo with oil after the engine is shut off?