Yes — a proposed class action has been filed, but no settlement or payout exists yet. The case is Hubof v. General Motors LLC, No. 2:26-cv-13622.
A proposed class action asks the court to let one case cover many owners. Pickup Truck Talk reports it was filed Sept. 24, 2026 in the Eastern District of Michigan in the Pickup Truck Talk report. It centers on the engine oil cooler, the part that cools engine oil, in heavy-duty Duramax trucks. No class has been certified yet.
Official resources:
- Read the official notice from Carpro — Use this primary source to verify the official announcement.
- Read the official notice from Theautowire — Use this primary source to verify the official announcement.
Table of Contents
- Which trucks are included?
- What failure is alleged?
- What happened to the lead truck?
- What does the lawsuit seek?
- What should owners do now?
Which trucks are included?
The filing proposes a nationwide class for U.S. buyers and lessees with the 6.6-liter L5P Duramax diesel. It names 2024–2026 Chevrolet Silverado 2500HD and 3500HD trucks.
It also names 2024–2026 GMC Sierra 2500HD and 3500HD trucks. A separate Idaho class is also proposed. Check these three points against your paperwork:.
- 2024, 2025, or 2026 model year
- Silverado 2500HD or 3500HD, or Sierra 2500HD or 3500HD
- 6.6-liter L5P Duramax diesel engine
What failure is alleged?
The complaint alleges the engine oil cooler can crack during normal driving. The Auto Wire reports the crack can push pressurized oil into coolant or leak externally, causing sudden oil loss and engine failure in The Auto Wire analysis.
The suit further alleges GM knew of the problem. It claims coverage was denied by blaming low oil or poor maintenance. A cracked cooler can itself lower the dipstick reading, so low oil may be a symptom rather than the cause.
What happened to the lead truck?
Lead plaintiff Robert Hubof alleges his new 2024 Silverado 2500HD failed in June 2025 at about 16,453 miles. MotorBiscuit reports the truck made a bang, showed oil in the coolant bottle, had an oil-filled cooling system, and contained metal debris in the MotorBiscuit account.
He then received a $41,319.79 repair quote. The complaint alleges GM denied the repair under warranty. His experience is an allegation, not proof of how other trucks will fare.
What does the lawsuit seek?
The plaintiff seeks class certification, a jury trial, and damages. He also seeks court-ordered relief. That includes a supervised repair and replacement program for affected trucks.
Important limits apply. The allegations have not been proven. No class has been certified and GM has not been found liable, as noted by CarPro in the CarPro legal roundup.
What should owners do now?
The suit points to dealer documents rather than a safety recall. Service Update N232430450 in August 2024 held certain 2024 HD trucks for inspection.
Bulletin 25-NA-150 followed in June 2025 for coolant contamination. Owners who suspect this failure should preserve proof now:.
- Keep all repair orders and warranty denials
- Keep oil-change receipts and maintenance records
- Photograph coolant color, oil in the reservoir, leaks, and warning lights