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During normal operation the SRT - 4 turbocharger will emit a very high frequency whistle at full boost 68.9 - 103.4 kPa (10 - 15 psi) during WOT acceleration.

During throttle tip-out, the surge valve will emit a light air “woosh” noise. If there is excessive NVH or other air leak/turbocharger noises, the intercooler plumbing or turbocharger control system may be compromised.

TO identify the source of the concern, check for Diagnostic Trouble Codes (DTC'S) stored in PCM memory. If any DTC'S are present, refer to the appropriate Powertrain Diagnostic Information.

If there are no DTC'S stored, use the folling chart.

CONDITION POSSIBLE CAUSES CORRECTION UNDERBOOST - 20.6 - 27.5 kPa and turbocharger lag at WOT with some air leak noise OVERBOOST - 103.4 kPa (10 psi) or more even at part throttle (could be as high as 137.8 kPa (20 psi) or more). A "Fluttering" noise can be heard during overboost. CAUTION: Engine damage can result from prolonged Overboost. </B>Waste Gate control hose plumbing compromised/disconnected
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UNDERBOOST - 27.5 - 62 kPa (4 - 9 psi) @ WOT with "horse laugh" on throttle tip-out. Surge valve control hose plumbing compromised. Repair plumbing
NORMAL BOOST - but turbocharger lag and "horse laugh" noise on throttle tip-out. Surge valve scroll and vacuum feeds reversed Reverse vacuum lines ()
UNDERBOOST - 0-20.6 kPa (0-3 psi) a WOT with loud air leak noise outside vehicle. Turbocharger may emit a "howling" noise. Intercoooler plumbing hose disconnected Inspect plumbing

Very rough idle TIP/MAP sensor hoses connected improperly or TIP disconnected

CONDITION</B>

POSSIBLE CAUSES</B> Low boost pressure, lack of power Clogged air filter Leaks between engine and turbocharger Exhaust restriction Restriction in charge air cooler hose(s) Wastegate stuck open Wastegate actuator malfunction Seized turbocharger shaft Overboost Wastegate stuck shut Wastegate actuator malfunction Noisy operation or vibration Leak(s) in charge air cooler hose(s) Intake or exhaust leaks Oil starvation Worn turbocharger bearings Damaged turbine/compressor fins Blue smoke from exhaust Oil return line blocked Engine breather clogged Turbocharger shaft seals damaged