Which parts fail
Components named in complaints (fuel pump, injectors, fuel tank, hybrid and EV propulsion).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2004 Chevrolet Trailblazer EXT owners, lightly cleaned up (personal details are redacted by NHTSA).
I purchased a Chevrolet EXT Trailblazer on nov. 26, 2004. 2 months later on feb. 1, 2005 it was towed into the dealership after shutting down 5 times with 2 loud explosions. The malfuction of the vehicle came close to a couple of accidents occuring and an almost near death experience for my daugher and I when it shut down for on a 4 lane highway by attempting to cross it unto the residential area. The dealership informed me that the fuel injection valve had malfuctioned and remained open releasing all the gasoline unto the engine. They are replacing the injector, spark plugs/wires that were flooded with gasoline, and the intake gasket. I contacted GM which also confirmed to me that the series of events could have started a vehicle fire and the first time this happened I should have left the engine off and vacated it immediately. …
The vehicle was purchased in sept 2004. In March 2005 I started noticing it was hard to start in the morning when it was cold and it idled roughly and would stall when I pressed the gas pedal to accelerate. The dealer found nothing wrong with it then. In April 2005, with 9400 miles on it, the service engine light came on so I took it back to dealership. They cleaned out (flushed) the fuel system and proceeded to tell me not to buy "cheap gas" because sometimes it will have particles in it that can clog up the fuel system (then what is the fuel filter for?). Since then I have had the fuel system flushed three more times. I probably could have had it done more times, but it is extremely inconvenient to keep going to the dealership and being without a vehicle, so I just dealt with the rough idle and hesitations. …
The dealership that we bought our car from didn't want to fix our problem being that we didn't have and extra 1500 dollars to buy an extra warranty for the car about three weeks later after taking it off the lot at a store the car didn't come back on so we called and asked a mechanic what could be wrong and they let us know that it could be the fuel pump or some thing to do with the fuel lines so we took it in to get checked and it was the fuel pump and the fuel tank so we called the dealership and told them what happened and they told us that they would talk to the manager and see what they can do so then about two hours later they called back saying that they couldn't do nothing because of the fact that we didn't buy the extra 1500 dollar warranty so I told them that it wasn't even thirty day after we took the car off the lot and all they could say is that they were sorry we didn't …
Due to a service engine soon warning light and smelling gas inside my vehicle, I took my vehicle to my local mechanic. He stated there was a crack in the neck of my fuel tank. The tank needs to be replaced. He also stated that this is a common problem with trailblazers. I then took the vehicle to the GM dealer where it was purchased. Their initial diagnosis was the fuel cap needed to be replaced. At that point I asked them to check for a crack. They did and verified there is a crack. I mentioned GM campaign 07099a - a recall for Trailblazer EXT's to remedy this problem by replacing the fuel tank at no charge. Unfortunately, this recall only affected certain VIN #'s and mine is not within the affected number range. I believe this is a very dangerous safety defect that should be remedied by the dealer at no cost to me. …
I have a 2004 Chevrolet Trailblazer EXT with 161,000 miles on it. A few weeks ago I got to noticing a real strong gas odor in and around the vehicle. I have done a lot of research and have had the vehicle checked out and came to the conclusion that it is the common problem that is affecting many other Trailblazer EXT owners. It is the fuel tank inlet check valve at the top of the fuel tank. In doing my research I have noticed that many people have had this issue fixed by some recalls that have been issued so I took the vehicle to my local Chevrolet dealer to find out about it only to be informed that mine is 41,000 miles past the recall mileage and will cost upwards of $1,000 to fix. I am worried about a possible fire or explosion with this issue. I am afraid to drive it to work every day and to use it to take my children to school. …
On several occasion over the past year my fuel gauge in my 2004 Chevrolet Trailblazer lt has read inaccurately leading to breaking down due to the vehicle running out of gas while the gauge was still reading at least 1/4 tank moments before the engine stalls. On all occasions I was driving on the freeway the gauge showed 1/4 tank and then all od a suddenly dropped to e with the fuel warning light coming one. Within a few miles of this sudden drop and the warning light coming on the engine would stall due the vehicle being out of gas. I have complained to my local dealer on several occasions and all they have offered to me is to replace the sending unit, which in this model is integrated with the fuel pump at the cost of almost $800. This seem wrong to me. …
My wife's 2004 Trailblazer EXT service engine soon light came on in late September 2009. She had been complaining of a gasoline smell after filling the vehicle. I had the obdii code read and it was code 0440 evaporative fuel system - small leak. I was told to replace the gas cap, and it did not remedy the problem. I then found out that the 2002-2004 Trailblazer EXT had a known problem with the gas tank filler necks developing cracks and causing the ses light to come on and gas to leak when the tank is filled or near full. I contacted Chevrolet, who stated that out Trailblazer is not in the VIN range of Trailblazer EXT's that were covered by a special notice that allowed the tanks to be replaced under a special extended warranty. The replacement cost is $900+. This is a known problem with 2004 Trailblazer EXT, outside of the narrow VIN range that Chevrolet will admit to. …
Service engine soon light came on. Took it to auto zone and computer diagnosis was EVAP emission leak, small. Code:p0440. This happened twice over 2-3 week period. Replaced gas cap, that was not the problem. Light came back on. Took to dealership garage, I was told that I had a significant leak in my gas tank, at the filler neck, would cost $900 to fix it. Thing is, I had been driving this car around for over 3 weeks with my 2 small children in it with the possibility it could have caught on fire! How scary is that? Dealership said it was not safe to drive due to possibility of catching fire. Contacted GM consumer service, awaiting their return call. They didn't seem interested in helping me. I know previous yrs (2002, 2003, and early 2004 models) have the same problem and was covered by GM or were recalled. I have never received a recall notice. …
I just gased the Chevrolet Trailblazer and was driving down the road and we could smell gas did not think much of it because we just got gas then the check engine light came on it was a po442 code evaporative emission control small leak detected so I have been smelling gas off and on and keep getting the po442 code. So I go buy a vent valve solenoid and put it on clear the code I notice gas around the intake pipe on the gas tank so I take a closer look and its broke half way around the filler neck and this is a recall on certain VIN #s but mine is not included in this recall I think it should be when you are dealing with fuel and the amount of fuel that can leak out this can be a fire hazard for sure I think GM needs to step up and take care of this problem on all vehicles that have this problem instead of picking an choosing certain VIN #s.
We were doing our normal fill-up (truck was off) and after we filled it up & turned it over, the fuel gauge shot way over the 'full' mark. Every time we turned the vehicle on, the fuel gauge was reading differently, I have no idea how many times it was right. The oil pressure and battery charge gauge have also been giving false/sporadic readings as well. After much searching, I found the root cause of this to be a very common problem not only in the trailblazers but the tahoes and several other of their vehicles (the instrument clusters are faulty). Given the expansive nature of this issue, and the potential dangers of not knowing your speed, fuel level, oil pressure or rpms, I'm having problems seeing why this isn't a recall already. It seems to happen more in the 2003-2006 models more than others from what I've found as well.
NHTSA investigations
Fuel pump module leaks gasoline
During the course of this ea investigation, odi observed that the majority of the complaints (88%) and warranty claims (94%) were reported for vehicles that are registered for use in the salt belt region of the us.this area includes 20 states in the northeast, mid atlantic and the midwest regions and the district of columbia.consumers in the salt belt region reported to odi that they could smell fuel vapors in their…
Fuel System complaints in other Trailblazer EXT years
Frequently asked questions
How common are fuel system problems on the 2004 Chevrolet Trailblazer EXT?
NHTSA has 46 complaints about the fuel & propulsion system of the 2004 Chevrolet Trailblazer EXT, 18% of the model year's 261 complaints. The component named most often is storage › fuel gauge system (3 mentions).
Is there a recall for 2004 Chevrolet Trailblazer EXT fuel system problems?
No. NHTSA lists no fuel & propulsion system recall for the 2004 Chevrolet Trailblazer EXT, though it has 1 recall for other components. If the problem is widespread, a repair may still be covered by an extended warranty or a manufacturer service bulletin — ask a dealer.
At what mileage do 2004 Chevrolet Trailblazer EXT fuel system problems start?
Half of the complaints with a recorded mileage happened before about 83,000 miles, and 8% before 25,000 miles.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.