General Motors overhauled its full-size SUV lineup with a range of fresh next-generation models, all of which were introduced for the 2021 model year. Now, however, the automaker has issued a new TSB (Technical Service Bulletin) that addresses a potential issue related to the engine oil cooler lines on the 2021 Chevy Tahoe, Suburban, GMC Yukon, and Yukon XL.
The bulletin was issued last month, and states that some of the full-size SUV models could have one to two engine oil cooler lines that are not fully seated into the quick connect at the radiator.
Affected vehicles include the following:
The TSB was issued specifically for vehicles in dealer inventory. Dealers are instructed to inspect the engine oil cooler lines at the quick connector on the radiator in order to ensure they are properly seated before selling or dealer-trading the vehicle.
No parts are required for the fix. However, catastrophic engine failure can occur if the oil cooler line is not properly seated. There are a total of two lines to check.
This TSB applies to both of the gas-powered engines offered in the 2021 Chevy Tahoe, 2021 Chevy Suburban, 2021 GMC Yukon, and 2021 GMC Yukon XL, including the naturally aspirated 5.3L V8 L84, and the naturally aspirated 6.2L V8 L87.
Most of the vehicles this TSB applies to are in dealer inventory. The fix should be done by the dealer prior to the dealer delivering the vehicles.
All four full-size SUVs affected by this TSB enter a new generation for the 2021 model year. All four ride on the new GM T1 platform, and are produced by GM USA at the GM Arlington plant in Arlington, Texas.