GM is facing a new lawsuit alleging it concealed an oil cooler defect in some of its heavy-duty trucks and refused to honor warranty coverage for resulting engine damage.
The details: The lawsuit alleges that when the oil cooler—which uses engine coolant to regulate oil temperature while keeping the two fluids separate—cracks, pressurized oil can enter the cooling system or leak from the truck, potentially causing engine failure, according to Top Class Actions.
Plaintiff Robert Hubof claims that in June 2025, he heard a loud bang in his 2024 Chevrolet Silverado 2500 HD, which had about 16,453 miles on the odometer, before discovering oil in the coolant reservoir and leaking beneath the truck.
A GM technician found engine oil in the cooling system and metal debris in the oil system, but the repairs were not covered under warranty, leaving Hubof with a $41,319.79 repair estimate, according to the lawsuit.
Hubof, who has been seeking other GM truck owners potentially affected by the issue, alleges that the automaker denies full warranty coverage by attributing the damage to poor vehicle maintenance.
He also claims GM often covers only the replacement oil cooler, even when the engine itself needs replacing.
What they’re saying: “At this time, nothing to add to your story as GM generally doesn’t comment on pending litigation,” a GM spokesperson told CDG News via email.
Why it matters: The lawsuit raises concerns about potentially costly engine repairs and warranty coverage for GM heavy-duty truck owners, which could lead to increased service inquiries and customer disputes at dealerships.
It also underscores the importance of clear communication about warranty decisions and repair costs, particularly when customers face significant out-of-pocket expenses.
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Between the lines: The lawsuit comes months after the National Highway Traffic Safety Administration (NHTSA) announced it was expanding an investigation into nearly one million GM pickups and SUVs over a separate engine defect tied to a 2025 recall.
Models under investigation include the 2021–2026 Cadillac Escalade, Chevrolet Silverado 1500, Suburban and Tahoe, and GMC Yukon and Sierra 1500 equipped with L87 engines.
The initial 2025 recall covered nearly 600,000 vehicles from the 2021–2024 model years due to supplier quality issues, following reports of engine failures while vehicles were in motion.
Since the 2025 recall, GM has received roughly 7,000 reports of engine failures involving pickups and SUVs that had undergone repairs, while NHTSA has received 499 complaints.
Bottom line: The latest lawsuit adds to GM’s broader engine-related challenges, raising questions about repair costs, warranty coverage, and customer confidence, with potential implications for dealer service operations, customer satisfaction, and long-term loyalty to GM’s truck brands.
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