LS6 Engine Hoot, Whine or Whistle Type Noise at 2200-3000 RPM While Driving, Stationary or Coming from Front of Dash On Acceleration (Replace Water Pump Inlet Housing Including Thermostat and Gaskets)
| Subject: | LS6 Engine Hoot, Whine, or Whistle Type Noise at 2200-3000 RPM While Driving, Stationary, or Coming from Front of Dash On Acceleration (Replace Water Pump Inlet Housing, Including Thermostat and Gaskets) |
| Models: | 2004-2005 Cadillac CTS-V |
| with 5.7L V8 Engine (VIN S - RPO LS6) |
| Built Prior to VIN Breakpoint 60123719 |
This bulletin is being revised to provide new service information. Please discard Corporate Bulletin Number 05-06-02-009 (Section 06 -- Engine).
Condition
Some customers may comment on a hoot, whine or whistle type noise coming from the front of the dash on acceleration. This noise may also be heard at 2200-3000 RPM with the engine temperature between 79-93°C (174-200°F) while driving or when the vehicle is stationary.
Cause
The source of this noise may be from a flutter caused by coolant flow passing the thermostat round bypass plate.
Correction
Important: The water pump inlet housing and thermostat MUST be replaced as an assembly. The thermostat is not serviceable separately.
A new design water pump inlet housing with a revised thermostat round bypass plate has been released to eliminate this type of noise. Technicians are to replace the water pump inlet housing, including the thermostat and gaskets, with P/N 12600172 (kit). Refer to and copy out all of the appropriate repair procedures from SI (Service Information) before attempting the repair.
Parts Information
Part Number | Description |
|---|---|
12600172 | Water Pump Inlet Housing, (Including Thermostat and Gaskets [Kit]) |
Warranty Information
For vehicles repaired under warranty, use:
Labor Operation | Description | Labor Time |
|---|---|---|
J3500 | Thermostat, Outlet and/or Gasket - Replace | Use Published Labor Operation Time |
