The vehicle (2021 GMC Yukon Denali) has suffered three consecutive, catastrophic failures of the engine's rear main seal. Following the initial replacement—which requires mechanics to unbolt and drop the vehicle's exhaust system—a massive exhaust leak developed in the engine bay. The vehicle is now actively pumping toxic exhaust fumes directly through the air conditioning vents into the passenger cabin, creating an immediate carbon monoxide inhalation hazard. The underlying mechanical issue is a chronic failure: either excessive crankcase pressure (clogged PCV system) is repeatedly blowing the engine seals, or the dealership technicians failed to properly align and seal the exhaust flanges/gaskets upon reassembling the vehicle. General Motors corporate has been notified of this recurring, unresolved safety defect. The vehicle is currently undrivable due to the severe buildup of fumes inside the passenger compartment while the engine is running.
GMC Yukon fuel smell problems
20 of the 5,036 owner complaints about the GMC Yukon describe gas smell in the cabin, most of them for the 2021 model year.
- owner complaints
- 20
- worst model year
- 2021
- typical mileage
- 100,000
By model year
- 20221
- 20214
- 20171
- 20162
- 20152
- 20081
- 20052
- 20041
- 20012
- 20001
- 19991
- 19981
- 19971
Often reported together
Fuel pump 9Check engine light 4Fuel leak 3Loss of power 1Fuel gauge 1Fire or smoke 1
What owners say
Exhaust fumes and stink on cold start . vehicle only has 40,000 mi and I have exhaust smells coming in through hvac system!!
When initially turning the vehicle on for the day and turning on the heater, the cabin fills up with exhaust fumes odor. This also happens while the car is idling and not moving. Have taken it to the dealership and they do not know how to proceed or what is wrong with it.
THE fuel pressure line from the fuel pump to the flex fuel sensor chaffed a pin hole leak near the front top of the fuel tank. This caused a significant fuel smell and trace leak at the front of the fuel tank which could lead to a fire or explosion. The new hose has a longer chaffing covering leading me to believe gm knew about this issue. vehicle has 127,000 miles. I feel gm should reimburse me for this repair as a fuel line should not have ever chaffed through and leaked.
High pressure fuel pump regulator failed and cause gas leaking, reduced engine power and gas smell coming back in vehicle. It was also blowing out white smoke. It had delayed ignition starting. The engine light did come on. Several makes and models of GMC has had recalls for this problem. The 2017 GMC Yukon was not included for this recall and should have been.
My family and I purchased this vehicle brand new in August 2021. We live in Phoenix Arizona and bought it from Earnhardt Buick & GMA in Mesa, AZ. While driving the vehicle in the last few weeks I personally could smell a strong odor of fumes in the cabin when the A/C or Heater were on. After a few days of noticing it my nose got numb to the odor as I dismissed it and kept driving the vehicle. After about a week, I had my two kids in the vehicle, they both noticed and made comments on how strong the odor of fumes were. We decided to not utilize the A/C or the Heater and contacted the dealer for investigation and repairs. This is a very serious health hazard as I and my family were exposed to exhaust fumes entering the cabin. For a few days and nights I suffered headaches and some dizziness as I was driving mostly the vehicle. We did take it to Earnhardt Buick & GMA in Mesa, AZ for investigation and repair. The maintenance supervisor confirmed that indeed somehow the exhaust had some crack that allowed fumes to enter the ventilation system. The Vehicle is now under repair at the dealership. I was notified by the maintenance advisor that this defect would not be cover under warranty as the vehicle is out of manufacture warranty. I Also had purchased an extended warranty (Platinum) which they had stated "bumper to bumper", but this also does not cover the manufactures defect. There were no warning lights associated with this problem. I would strongly recommend that inspections be made, especially if some drivers have problem with smell and odors. This is a big health hazard. Thank you for your attention. [XXX] . [XXX] [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
The vehicle was not starting and after 3 attempts it started, but a strong smell like gasoline came inside the car, and as I checked, fuel was running all the way to the ground. Major hazard! The vehicle was taken to the dealership and diagnosed with a leak in the High-Pressure Fuel Pump. According to the service advisor NOT COVERED under powerterain warranty. The part just went bad, and needs to be replaced. However, the vehicle has been in the service department since July 3 (Now it is July 18) and the part is in back order and no news as of when my vehicle will be fixed. My vehicle is a 2021 and I do not understand how a part is not available, or discontinued (according to parts department). I need my vehicle fixed!
Fuel pump leak. our cabin fills up with exhaust causing myself and my 3 young kids (1,3,5) to start coughing, eyes and throat burning, headaches & a hard time breathing. confirmed by GMC dealer in concord & separate auto shop. They told us it had a recall and that they couldn't fix it after paying them to diagnose it since it was recall. Now GMC dealer is telling us that the problem and recall exists for other 2015 Yukon models but our VIN # Is not included and that's why they never fixed the problem that I've been complaining about since I bought the truck (dont remember exact purchase date but the vehicle was new and under warranty for years). I've taken it to the dealership 3 times for the same problem (exhaust smell in cabin) and they kept saying it's fine. Now it's so bad that we can't drive it because it makes us feel sick.
Car keeps running rough, stuttering when switching off, smells like gas. Engine light comes on and goes off every other day. Started after fuel injector recall, dealership says it's the fuel pump leaking and unrelated to the fuel injector problem. I don't know if they changed the gaskets and the lines when fixing the injectors. It's a high pressure fuel pump with direct injectors.
Raw fuel fumes inside the cab and outside the vehicle. After looking under the vehicle there is a slow but steady fuel leak from the gas tank. I believe it is the plastic fuel line that has worn a hole in itself from rubbing on another object.
Related recalls
Fuel system, diesel: storage: tank assembly
- What is wrong
- General Motors, LLC (GM) is recalling certain 2021 Cadillac Escalade, 2021, 2023-2024 Chevrolet Tahoe, and 2022 and 2024 GMC Yukon vehicles equipped with a 6-cylinder diesel engine. The original fuel tank may have been replaced with an incorrect fuel tank, which can allow fuel to leak in a rollover crash.
- Risk
- A fuel leak in the presence of an ignition source increases the risk of a vehicle fire.
- Remedy
- Dealers will inspect for the correct fuel tank and replace it, if necessary, free of charge. Owner notification letters were mailed November 5, 2025. Owners may contact Cadillac customer service at 1‑800‑333‑4223, Chevrolet customer service at 1‑800‑222‑1020, or GMC customer service at 1‑800‑462‑8782. GM's number for this recall is N252512770. Vehicle Identification Numbers (VINs) involved in this recall became searchable on on September 18, 2025.
Recall number 25V619000 · Recall details
Fuel system, gasoline: delivery: fuel pump: control/drive module
- What is wrong
- General Motors, LLC (GM) is recalling certain 2021 Cadillac Escalade, Escalade ESV, Chevrolet Suburban, Tahoe, GMC Yukon, and Yukon XL vehicles. The fuel pump power control module may cause the fuel pump to fail or operate intermittently, which can interrupt fuel flow to the engine, and cause an unexpected engine stall.
- Risk
- An engine stall increases the risk of a crash.
- Remedy
- Dealers will replace the fuel pump power control module, free of charge. Owner notification letters were mailed on October 14, 2021. Owners may contact Chevrolet customer service at 1‑800‑222‑1020; Cadillac customer service at 1‑800‑458‑8006; or GMC customer service at 1‑800‑462‑8782. GM's number for this recall is N212332040.
Recall number 21V739000 · Recall details
Fuel system, gasoline: storage: tank assembly
- What is wrong
- General Motors, LLC (GM) is recalling certain 2021 Chevrolet Tahoe and GMC Yukon vehicles. The fuel tank assemblies may be missing adhesive between two layers of the fuel tank shell which may result in a fuel leak.
- Risk
- A fuel leak in the presence of an ignition source increases the risk of a fire.
- Remedy
- GM will notify owners, and dealers will replace the fuel tank, free of charge. The recall began March 6, 2021. Owners may contact Chevrolet customer service at 1‑800‑222‑1020, and GMC customer service at 1‑800‑462‑8782. GM's number for this recall is N212327720.
Recall number 21V064000 · Recall details
Fuel system, gasoline: delivery: fuel pump
- What is wrong
- General Motors LLC (GM) is recalling certain 2020 Cadillac Escalade, Escalade ESV, Chevrolet Camaro, Silverado 1500, Suburban, Tahoe, GMC Sierra 1500, Yukon, and Yukon XL vehicles. The fuel pump may be missing a pressure regulator, allowing for over-pressurization of the fuel system.
- Risk
- Over-pressurization can crack the fuel pump and cause leaks, increasing the risk of a fire in the presence of an ignition source.
- Remedy
- GM will notify owners, and dealers will replace the fuel pump, free of charge. The recall began December 18, 2019. Owners may contact Cadillac customer service at 1‑800‑333‑4223, Chevrolet customer service at 1‑800‑222‑1020, or GMC customer service at 1‑888‑988‑7267. GM's number for this recall is N192283991.
Recall number 19V837000 · Recall details
Fuel system, gasoline
- What is wrong
- Gm is recalling 27,188 my 2009 cadillac escalade, escalade hybrid, escalade esv, and escalade ext; chevrolet avalanche, suburban, tahoe, tahoe hybrid, and colorado; and gmc yukon, yukon hybrid, yukon xl, and canyon vehicles. The fuel system control modules may have a condition in which an adhesive separation of the room temperature vulcanizing (rtv) seal between the seal and the housing may allow water to seep into the module.
- Risk
- Water in the module could cause a short or open circuit, illumination of the service engine soon lamp, setting of diagnostic trouble codes or the engine may be hard to start, may not start or may stall increasing the risk of a crash.
- Remedy
- Dealers will install a new fuel system control module free of charge. The recall began on may 18, 2009. Owners may contact cadillac at 1‑866‑982‑2339, chevrolet at 1‑800‑630‑2438 and gmc at 1‑866‑996‑9463 or at www.gmownercenter.com.
Recall number 09V154000 · Recall details
Questions about the GMC Yukon fuel smell
Which GMC Yukon years have gas smell in the cabin problems?
The model years with the most reports are 2021 (4 complaints), 2001 (2 complaints) and 2005 (2 complaints).
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