Three problems related to tank mounting have been reported for the 2004 GMC Envoy. The most recently reported issues are listed below.
The cluster gauge quit working. First the gas gauge stopped reading the amount of gas in the tank. Second, the speedometer and tachometer quit reading. About a month later the oil pressure gauge stopped working. Currently out of the entire cluster gauge system the battery meter is the only gauge that works.
The contact owns a 2004 GMC Envoy. The vehicle was purchased on September 29, 2004 and the mileage was 90. On March 27, 2007 tightened gas cap light came on. On March 30, 2007 the dealer stated that there was a leak coming from the neck hose connected to the gas tank and the fuel pump. The dealer stated that the gas tank had to be replaced. The contact was concerned about the safety risk involved considering the year of the vehicle. The failure mileage was 38,200, and the current mileage was 39,600.
A year after the purchase of my new 2004 GMC Envoy xuv my service engine light came on and an authorized service tech said I needed a new gas cap because of a small vapor leak. I bought the new cap and a few months later the engine light came on and again I bought another cap. From then I had been told by different mechanics that the vapor leak is coming from the nozzle the cap attaches to but today for the first time I was told I would fail my smog check because the vapor leak according to their diagnostics was not coming from the nozzle, but somewhere else near the tank. After research on recalls and complaints, I found out that my problem was similar to other complaints, that being the gm service bulletin 05-06-04-014a: info - diagnostic aids for trouble codes p0440, p0455 & / or p0442 fuel was leaking from the crack, and that the 2002 - 2004 Envoy may have issues with a crack in the gas tank filler neck as well. I checked out the assembly system and yep my filler tank connection from hose to tank is loose and showing evidence of gas leaking down the tank. It wasn't a small vapor leak, it is a mushroom cloud event just waiting to happen to my backside! the interesting part of this disaster is that they did this as far back as I could search, so far as early as 2001. Gm had advised their mechanics that the problem was resolved and redesign of the system was in place with welded units attaching the components, rather than rubber booting to plastic tanks. I have the internal memo of their declarations for three years so far. Today, I'm in possession of a loaded bomb and see that TSB's are issued for years through 2009. Plus theres a discrepancy with service warranties of 10 years or 120,000 miles vs 150,000, I have those internal documents from gm to the dealers as well. I cant afford this. Other Envoy owners I've talked to are saying the same things exactly.