GMC Canyon overheating problems

Filed Sep 9, 2026 · Driver assistance, Transmission · FL

I’ve included all my repair orders regarding to coolant smell/leak and transmission shutter. I purchased my truck on XXX. We had planned a family vacation to [XXX], and we were driving up when I felt the transmission shutter at around 3:00 to 5:00 p.m. while cruising at approximately 55 to 62 mph. Since then, I’ve noticed it happening more frequently. I took the truck to GMC dealer Jack Hanaia at [XXX] (I believe it was in XXX). I expressed my concerns, and they couldn’t find any issues with the transmission, along with the coolant leak. They claimed they couldn’t find a leak, but the service advisor could smell a strong coolant leak. Later on March 5th the coolant leaked, and I got a different advisor. She could smell the leak but the tech couldn’t replicate the issue. A few months later, around August, I took the truck to a different dealership, the Buick GMC dealership at [XXX]. I informed them that I had a coolant leak smell, a transmission shutter, and other issues listed on the repair order They couldn’t find the transmission problem or the coolant leak, but the advisor could also smell the coolant leak. I’m getting tired of going to the dealership and getting a turnaround to go home with the same issue. I have issue with parking sensor blocked all the time. My AC issue is becoming more problem for me, the temp doesn’t match the reading with a thermometer, it’s way off to the point where I have to turn it to LoW to get max cold. When set at 65, it feels like 75 degree. I have videos. My last 2009 GMC Canyon 3.7 crew cab treated me and my family well for 13 years. I bought it in 2013 and sold it in XXX. I thought to choose GMC Canyon over Toyota Tacoma, but now that I’ve been experiencing this issue nonstop, I’m regretting the decision to pay the truck in full cash. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Apr 22, 2026 · Engine · AZ

Coolant leak observed at the upper radiator hose quick-connect fitting. The leak appears to originate from the internal seal at the radiator inlet connection. This issue developed without warning and is consistent with a known defect in the radiator hose seal design used in 2023 GMC Canyon vehicles. Vehicle experienced coolant loss and visible residue at the connection point. No visible external damage to the radiator or hose assembly was observed. GM has issued a Special Coverage program for similar radiator inlet hose seal failures in related vehicles using the same component design. Concern is that this defect may lead to coolant loss and potential engine overheating if not addressed.

Filed Apr 14, 2026 · Electrical, Engine · TX

The engine coolant temperature sensor has failed on my 2019 GMC Canyon. The check engine light is illuminated, the temperature gauge does not register correctly, the air conditioning has been disabled by the vehicle's computer, and the engine cooling fan continues to run after the engine is turned off. These symptoms are consistent with the vehicle entering fail-safe mode due to loss of a valid coolant temperature signal. The problem was confirmed by an independent mechanic who diagnosed a failed coolant temperature sensor. The mechanic attempted to source a replacement part through GMC but was informed the part was unavailable. The reason for the parts unavailability is unknown, though in his experience, it typically means that the manufacturer is stocking up and preparing for a recall This issue appears to be widespread across 2017–2020 GMC Canyon and Chevrolet Colorado V6 trucks based on extensive owner forum documentation. The safety concern is significant: without reliable coolant temperature monitoring, there is no assurance the engine is operating within safe thermal limits, and the driver has no warning if overheating occurs. The disabled A/C also creates a safety risk during periods of extreme heat. The vehicle has approximately 60,000 miles. The problem has been present for approximately three months and is ongoing.

Filed Mar 9, 2026 · Engine · VA

Coolant leak caused by known manufacture defect in upper hose assembly causes coolant to drain and engine to overheat. CEL only comes on when coolant is almost gone. GMC refuses to cover the known issue after 36k miles.

Filed Mar 7, 2026 · Engine · SC

Coolant Leaking at 22K miles, smell of coolant, check engine light on and off 2X's. Coolant evidence on driveway and in engine cabin. Known condition for GM Model. No parts available for replacement. No recall for issue.

Filed Feb 27, 2026 · Engine · VA

Upper radiator hose connection to radiator is faulty causing leak of coolant. Yes it is available for inspection upon request. Truck began to run cooling fan at full speed in the middle of winter with no warnings of high heat or low coolant. After two weeks, check engine light finally cut on to indicate low coolant flow. Coolant reservoir was subsequently checked and found to be completely empty. It is apparent this reservoir had been extremely low / empty for at least two weeks with no warnings. Without proper warning and leaking coolant, truck could have overheated. Should this had happened in dead of summer, truck could have very well overheated with no warning. The problem was investigated and confirmed by dealer as leaking coolant at the connection of the upper radiator hose to the radiator. Was quoted $983 to replace the hose. No warning lights appeared until issue had been ongoing for over two weeks. A quick search of "GMC Canyon Upper Radiator Hose" will reveal many identical occurrences of this issue. This is a safety hazard / design flaw that GM is not acknowledging and is putting the burden on the vehicle owners for their own issue.

Filed Feb 25, 2026 · Engine · AZ

The upper radiator hose on some huge percentage of these trucks fail (mine has failed at just over 37K miles). You can check the Colorado Chevy and GMC Canyon forums, youtube, Facebook, etc., et al, and find plenty of instances where this has failed. As this is the cooling system, it can cause the engine to overheat and potentially ruin the engine. The flaw seems to be an engineering issue with the rubber seal they use (instead of a high quality o-ring) to seal the upper hose to the radiator. Additionally, since this can cause engine failure it should be addressed immediately. Instead, my local Chevy dealer, since its not a recall item, said they could schedule a time next week for me to LEAVE the truck and that I am responsible for the repair. This is extremely unfair to the consumer who depends on these vehicles. This should absolutely be a recall item. You can find 1000's of examples online and if you can pull GM repair data, I'm sure you'll find 1000's more.

Filed Jan 19, 2026 · Engine · VA

There are widespread reports of the O ring seals on the radiator and heater hoses failing and causing coolant leaks. These leaks are significant enough to render the vehicle inoperable and with no cabin heating or cooling. This could lead to life-threatening situations in adverse weather conditions. It could also create dangerous roadside failure situation in heavy traffic, particularly on interstate highways. Dealers are aware of the issue and are currently repairing vehicles under warranty. However some dealers are telling owners that the cooling system is not part of the engine and drivetrain, and therefor is not covered under the original factory warranty if the vehicle has exceeded the initial bumper to bumper warranty limits. Dealers are also telling owners that parts are on backorder due to high demand, and that repair wait times could take weeks. The vehicle is unsafe to operate with a known coolant leak. Video of leak (another owner) here. [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Jan 19, 2026 · Engine · IN

Upper radiator hose attachment is leaking due to faulty rubber gasket. This comes up across GMC Canyon groups on Facebook 10 times a day. It is happening to ALL of them mainly pre 2025 on 3rd gens. Part is on back order at all GMC dealers due to so much volume of issue. Happening as early as 10k-20k miles on brand new trucks causing over heating issues due to coolant leaking out. Hopefully a recall for the part is done before engines start blowing.

Filed Jan 5, 2026 · Engine · 13,500 miles · CA

The contact owns a 2025 GMC Canyon. The contact stated that while the vehicle was parked, the contact discovered a coolant leak underneath the front of the vehicle. No warning lights were illuminated. The vehicle was taken to a dealer to be diagnosed; however, the vehicle had not yet been diagnosed. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 13,500.