2014 - 2019 Cadillac ATS-V - CTS V-Sport: Service Bulletin: #19-NA-256: Diagnostic Tips for Knocking, Rattle, Squeak and/or Squeal Type Noise from Engine

#19-NA-256: Diagnostic Tips for Knocking, Rattle, Squeak and/or Squeal Type Noise from Engine - Engine Replacement Recommendations for HFV6 Gen 1 and Gen 2 - (Jan 14, 2021)

This bulletin replaces PIP5216G. Please discard PIP5216G.

Involved Region or Country	North America
Condition	Some customers may comment on one or more of the following conditions: Knocking noise Seized engine Lower end squeak or squeal
Cause	This condition may be caused by a crankshaft main or rod bearing failure.
Correction	Verify there is metal in the engine oil by removing the oil pan. Remove the main or rod bearing caps: If the main and/or rod bearing are not the cause of the debris, refer to SI for further diagnostics.     If the main and/or rod bearings are found to be the cause of the debris, before deciding whether to replace the engine or repair it, refer to the Service Procedure below before making that determination.

Service Procedure

 

 

1. Inspect the oil control solenoids for metal debris. This shows the oil filter is in by-pass and unfiltered oil with bearing debris was pumped into the oil lubrication galleys, throughout the engine.

 

1. Inspect for damage to the cam caps journals and camshaft journals on the heads (obvious signs of metal through the cap).

 

 

1. Inspect the timing chain idler sprockets for stiffness when turning (Should turn smooth and free).

Any of the above 3 instances would be cause to replace the engine instead of repair.

While engine replacement at this point will be necessary, additional inspections should also be made for conditions:

• Sludging caused by lack of maintenance. Refer to the latest version of Service Bulletin 16-NA-222.
• Global oil starvation caused by running the engine very low on oil.
• Intentional abuse to the engine.

If these conditions exist, warranty could be declined or feedback made on Warranty Parts Center (WPC) inspection. Maintenance documentation should be obtained in these instances for warranty validation.

Clearly document your findings on your repair order, fill out the cost worksheet, and call Product Quality Center (PQC) only if required for your dealer.

A repair and then replacement will usually be cause for additional inspection and scrutiny that could result in more questioning about the repair methods.

HFV6 engines are scheduled to be returned to the WPC for inspection to verify the concern, as well as the information provided in the repair order to support the engine replacement.

Additional SI Keywords: PIP5216, PIP5216A, PIP5216B, PIP5216C, PIP5216D, PIP5216E, PIP5216F, PIP5216G, PIP5216H, PIP5216I, PIP5216J, PIP5216K, PIP5216L, PIP5216M