Hi my car a ford focus st 2.5 leaves some blue smoke and sometimes backfires when shifting gears when on full boost. First thought that it could be a boost leak as intercooler leaked according to a dealer. Intercoolet replaced and still have the same problem. Could this be turbo seals thst is on the way out?
My car has a manual transmission.
You should disconnect the hose on the turbo to see if you see indications that the turbo has oil in the intake. The oil seals in the turbo may start leaking and will cause the smoke you are seeing. If you see oil on the turbo vanes and inside intake tubing then lift up and down on the turbo shaft to see if bearing play is felt. If oil leaks or bearing issues you will need to have the turbo rebuilt.
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