Service bulletin PIP-4957-B

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

The communication, as NHTSA indexes it (as of 2026-10-19)
Type	Service bulletin
NHTSA id	10052829
Published by NHTSA	2013-09-19
Manufacturer's number	PIP-4957-B
Manufacturer's date	2013-09-01
NHTSA component	ENGINE AND ENGINE COOLING:COOLING SYSTEM

NHTSA's summary

GM: ON SOME VEHICLES A HOOT, GURGLE, HOWL, OR SWOOSH NOISE MAY BE HEARD COMING FROM THE ENGINE ARE. REPLACE THE THERMOSTAT HOUSING WITH THE CORRECT PART NUMBER. ALSO INCLUDE MAKE/MODEL BUICK LACROSSE MODEL YEAR 2014. *JS

The document

No address for NHTSA's copy can be built for this communication. Ask the dealer for it by the manufacturer's number.

Components

Engine, Cooling system

Vehicles listed
BUICK LACROSSE	2011, 2012, 2013
CHEVROLET IMPALA	2012, 2013, 2014

Listing a model year does not mean every vehicle of it is concerned: the document says which.

Other bulletins for the same vehicles and component
14588C	2023-12-18. Service bulletin. Engine Cooling Fan Motor
PIP5684B	2020-08-10. Service bulletin. This Preliminary information communicates the use of air leak diagnostic test tool CH-52250 in addition to the information found in the service manual.
19NA104	2019-07-29. Service bulletin. This informational bulletin provides information for dealers/technicians and customers on steam/vapor coming from the front grille or radiator area.
PIP5257B	2018-08-20. Service bulletin. This Preliminary Information communication provides information to the technician on the steps to diagnose and repair vehicles that may have oil mixed in with the engine coolant. Technician will need to inspect the oil cooler if equipped for possible leaking into the cooling system through the radiator. If no issue found replace the engine as well as all rubber coolant hoses.
PIE0385B	2018-05-21. Service bulletin. This engineering information bulletin ends the need for information from the field on vehicles that have the concern of a noisy water pump.
PI1203	2018-05-21. Service bulletin. This preliminary bulletin provides information of a normal condition of steam coming from the front grill area after the front gets wet and then heats up from the engine components.
PIP4957B	2017-08-15. Service bulletin. This Preliminary Information communication provides information to the technician about vehicles that have a Hoot, Gurgle, Howl, or Swoosh noise from the engine cooling system. Technician will need to replace the thermostat housing with the correct part number.
PIP5093	2017-08-15. Service bulletin. This Preliminary Information communication provides information to the technician about vehicles that may have an engine oil leak that appeared as they were driving the vehicle in extremely cold ambient temperatures. The technician may find the oil leak is coming from the rear main seal. Technician will need to check for proper thermostat operation by following thermostat Diagnosis as outlined in Service Information and replace the thermostat as necessary. Also the technician will remove the cam cover, inspect the positive crankcase ventilation baffle inside, and replace the cam cover if obvious sludge build up is present. Any debris in the positive crankcase ventilation pipes, hoses, the positive crankcase ventilation nipple on the cam cover, and the throttle body should be cleaned out. Technician should inspect the related positive crankcase ventilation hoses/connections for potential damage and replace if necessary. Run the engine at operating temperature for 15 minutes at idle. Then turn the engine off, and drain the engine oil for at least 15 minutes to remove all oil and condensation or water from the crankcase. Follow Service Information repair procedures to repair any oil leaks that were induced as a result of the frozen positive crankcase ventilation system and excessive crankcase pressure. Technician should insure the Engine Control Module calibrations have been installed to adjust the engine oil life monitor to a maximum of 7,500 miles (12,070 KM) as well.
PIP4959C	2017-08-15. Service bulletin. This Preliminary Information communication provides information to the technician with information about vehicles that misfires or roughness on cold start up. Technician may find Diagnostic Trouble Code P0300 set. Technician will need to add coolant dye to the system and run the engine through warm up to circulate the dye. Pressurize the cooling system after a cold soak and inspect the cylinder with a bore scope for coolant dye. If coolant is found in the cylinder technician will need to contact General Motors Product Quality Center for engine replacement.
PIP4959D	2017-08-15. Service bulletin. This Preliminary Information communication provides information to the technician with information regarding high misfire rates always on #1 cylinder. A customer may complain of misfires or roughness on cold start up with a P0300 diagnostic trouble code. Technician is to add coolant dye to the system and run the engine through warm up to circulate the dye. Pressurize the cooling system after a cold soak and inspect the cylinder with a bore scope for coolant dye. Dye is used to identify coolant over residual fuel being that might be left in the cylinder. The technician is not to replace the cylinder head as it will not correct this concern. In some cases it is necessary to remove the head for inspection. Do not replace the engine for small surface pock marks or a pitting appearance this is normal and do not connect to coolant passages. Usually if porosity is present there will be a break in the carbon ring. Only replace the engine if true porosity is found. Technician is to call Product Quality Center with the latest version of bulletin 02-07-30-029 if porosity is found and engine replacement is required.