Oil cooler for truck is defective and thus allowed all oil to be mixed with the coolant. GM is stating they will flush engine and replace with exact same part. Very common issue and sad to have a $100k truck and it is junk.
2025 GMC Sierra 3500
Owner reports · Recalls · Investigations
Limited comparison data
There is not enough comparable history to draw a useful model-year comparison.
About this comparison →How this year compares
Owner complaints by model year
Compare all Sierra 3500 years →Counts vary with age, sales and reporting. They are not failure rates.
What owners reported most
All reported categories
Tap a category to read its complaints. One report may name several components.
When problems were reported
Mileage at the reported incident
Limited mileage data: 1 of 16 reports include usable mileage. There isn’t enough coverage to show a useful chart.
NHTSA’s mileage field refers to the reported incident, not necessarily the filing date. This shows report counts, not the likelihood of a failure.
What to inspect
Issues worth paying extra attention to based on owner reports.
- Service Brakes. Review the 4 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
- Electrical System. Review the 3 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
- Engine. Review the 2 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
NHTSA owner reports · September 18, 2026 snapshot.
Engine complaints
2 reports“I own a 2025 GMC Sierra with 30,000 miles. The oil cooler failed and caused loss of oil pressure and potential internal engine damage. The dealership acknowledges the failure but refuses to escalate the case or perform a proper inspection. I am being instructed to continue driving the truck even though it may suffer catastrophi…
Read full complaint
“I own a 2025 GMC Sierra with 30,000 miles. The oil cooler failed and caused loss of oil pressure and potential internal engine damage. The dealership acknowledges the failure but refuses to escalate the case or perform a proper inspection. I am being instructed to continue driving the truck even though it may suffer catastrophic failure while driving. This is a safety hazard.”
Official recalls
126V129000 · Fuel System, Gasoline:delivery:fuel Pump:control/drive Module
Mar 5, 2026
General Motors, LLC (GM) is recalling certain 2025-2026 Chevrolet Silverado 3500, and GMC Sierra 3500 vehicles with gasoline engines and dual fuel tanks (RPOs L8T and N2N). The rear fuel pump may not transfer adequate fuel to the front tank, causing an engine stall.
Consequence & remedy
Consequence: An engine stall increases the risk of a crash.
Remedy: The vehicle's engine control module (ECM) will be updated by a dealer or through an over-the-air (OTA) update, free of charge. Owner notification letters were mailed April 8, 2026. Owners may contact GMC customer service at 1-800-462-8782 or Chevrolet customer service at 1-800-222-1020. GM's number for this recall is N262544420. Vehicle Identification Numbers (VINs) involved in this recall became searchable on NHTSA.gov on March 5, 2026.
Model-level recall history does not show whether a particular VIN is affected or has received a repair. Check a VIN with NHTSA ↗
NHTSA investigations
0No exact-year investigations in this snapshot.
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