Huge amounts of white smoke under boost out the exhaust
Overboosting on the stock Hitachi turbo can damage the compressor carbon
seal. We have had very bad experiences with running over 15psi of
boost on the stock turbo (compressor carbon seal).
First of all, make sure the "PCV" (positive crankcase valve) system is working.
The FC3S does not have a PCV system per se, but it does use a "purge valve" to
recirculate vapors from the oil pan back into the engine to be burned. Those
of you who have "modified" or removed the emissions systems and vacuum hoses might
have inadvertantly modified this purge valve system incorrectly. Make sure both
of the two fittings on the oil filler pipe (one is at the base of the oil filler pipe
on top of the engine, and the other is at the top close to the oil filler cap) are
not blocked. If the oil pan section is not vented, it will pressurize
while the engine is running and cause oil it bypass the turbine piston compression
ring seal; extended periods of doing this can damage the turbo turbine piston ring
compression ring. Ideally, one of the fittings (top one is recommended) should
see vacuum at all times. You can vent at least one of the to atmosphere, but
the fitting does emit some nasty sludge; a catch can is highly recommended.
Oil bypassing the turbo compressor will allow significant amounts of oil to enter
the compressor housing, intercooler, and pipes. Inspecting the intercooler
and pipes for pools of oil will confirm this is the case. Checking the spark
plug tips will show excessive black, crusty deposits. In some instances, the
turbo turbine "piston compression ring" will fail, and oil will enter the exhaust
through the turbine section. Check the turbo turbine section, as the leaking
oil will usually seep between the flanges and bungs (i.e. O2 sensor). A turbo
that has a bad turbine piston compression ring will not foul spark plugs, as oil leaks
into the exhaust after it has passed through the engine. If the turbo is confirmed
to be the culprit, a turbo rebuild is necessary. Luckily, any turbo shop that
services Garrett turbochargers can do this for you, as the stock Hitachi turbos are
based on the Garrett T3 / T04 turbos; a Garrett T3 / T04 rebuilt kit will work on
the stock Hitachi turbo. If you are running an aftermarket turbo, please see
a dealer that can service your particular aftermarket turbo brand.
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