08-05-2012, 04:16 PM
TURBOCHARGING SYSTEMS
47047087-Turbocharger.pdf (Size: 88.04 KB / Downloads: 59)
OPERATING PRECAUTIONS
When Starting
After engine has started, allow it to run at idle for several
minutes. If engine has been shut down for a long period, be sure to
run engine at idle until engine oil has circulated throughout engine.
When turbocharger is replaced, remove oil pipe by loosening top flare
nut and pour fresh engine oil directly into oil filler port.
During Operation
Monitor oil pressure gauge to confirm that constant oil
pressure is available. If abnormal noise is produced by rotating parts
of turbocharger, or unusual vibration is noted, stop operation and
check.
When Stopping
Allow engine to run at idle for several minutes before
stopping engine. If engine is operated at high load, then stopped
abruptly, the engine oil supply is cut off while the turbocharger is
still very hot. The turbocharger bearings will be overheated and could
be damaged.
TROUBLE SHOOTING
Check the following items. If found defective, replace
turbocharger assembly. If related parts are defective,
repair or replace.
VIBRATION OR NOISE
1) Inspect for defective bearings or interference of
rotating parts with related objects. Consider neglect of engine oil
change, sustained use with contamination in oil pipe, a restricted or
broken oil filter. Check for repeated abrupt starts and stops that
could cause bearing failure.
2) If nothing is wrong with lubricating system, an
incorrectly balanced rotating section or bent shaft may be suspected.
This is due to excessive wear of bearings or contamination that have
caused damage to turbine or compressor wheels.
3) If any of these conditions exist, turbocharger assembly
must be replaced. Before a new turbocharger assembly is installed,
carefully check for contamination or pieces of broken turbine or
compressor wheels which might be left in manifold system.
LOW BOOST PRESSURE
1) Check air cleaner element for contamination or clogging
and clean or replace element as necessary. If turbine or compressor
wheels do not rotate smoothly and lightly when turned by hand,
replace turbocharger assembly. Check wastegate valve or relief valve
which might be left opened.
2) If turbocharger appears to be good, but has low boost
pressure, check for the following:
* Gas leaks in exhaust system.
* Deformed or clogged exhaust pipe or muffler which might be
causing increased exhaust resistance.
* Air leaks from compressor discharge side.
WHITE EXHAUST SMOKE
Sustained engine operation with faulty bearings will result
in failure of oil seal which could cause leakage of engine oil into
exhaust and intake pipes. Leakage of engine oil from turbocharger
into exhaust pipe or intake pipe will result in White colored
exhaust. If this occurs, check for clogged, crushed or deformed oil
return pipe. If nothing is wrong with oil return pipe, leakage is
probably due to wear of piston ring (seal ring) in turbocharger.
TESTING
Pressure Check
1) For Camry, connect a 3-way union to boost compensator
pressure hose and install a pressure gauge to it. While driving with
engine running at 2500 RPM or more (accelerator pedal fully depressed
in first gear).
2) For Pickup, connect a pressure gauge to fuel filter.
While driving with engine running at 2400 RPM or more (accelerator
pedal fully depressed in low range). Check the turbocharging
pressure. Standard pressure is 7.7-9.7 psi (.54-.68 kg/cm