I have a 2007 H3X that I bought used about a month in a half ago. Everytime we fill up, the engine idles REALLY low to the point of almost stalling out. Last fill up (2 days ago) it actually stalled. This happens immediately after fill up (using regular grade fuel from BP always) then it doesnt happen again. Any suggestions? Also in the last two weeks the fuel cap indicator light came on and the check engine light came on a few days after that.

The truck only has 40k miles on it. The other issue that I don't know is normal (because it has been gettting louder) is a creaking sound coming from the undercarriage during turns. It sounds like the truck is breaking in half. We only have 10k miles before the warranty runs out, but any info would greatly help!!

Tina
2007 H3X Desert Orange
2000 Yamaha YZFR600
2006 Suzuki GSXR750
1996 GMC Sonoma

 

Does the engine light turn on and stay on when it stalls? If so, the computer has stored a code indicating something. You would have to decipher the code with a meter. That is extra strange. The undercarriage seems to be maybe some joints which need lubrication with a grease gun. Most oil change shops say they greased the fittings and dont. Thats why I do it myself.

 

The check engine light would stay on constantly and the "fuel cap" indicator words would appear by the mileage. Apparently the GMC dealership says that there is a valve and cylinder that is supposed to let the truck know when it is full on gas. This unit had not been doing it's job on stopping the fuel, so it would overflow, causing the fuel to get sucked into the injectors. They did 8 updates on the computer, reset the computer, and blew out the gas lines, as the cylinder that got full of gas, is full of charcoal that got into the gas lines. They said the truck should run better now, but it might still have chunks of charcoal in the lines. Sounds like a load of crap to me, but today she has been running great! Thank for the advice madmike.

 

As it turns out, our Hummer is spending more time at the dealership than on the road. We keep finding little issues with it. The stalling issue was a bad valve in the gas tank and we had to get the whole tank replaced last month. We had issues with the door indicator light coming on last month saying a door was open (but only in the rain), which turned out to be a leak in the sunroof which the sunroof had to be replaced. Now the horn sounds like a dying duck...it is low and hardly noticable when the alarm sounds. The dealership is going to look at that soon. We also had to take the truck in when we first bought it (Dec 08) due to a rattle from the roof....turned out the clips on the roof rack were cracked and the dealership replaced the center piece of the roof rack. Now a clip is broken on the roof rack light over the drivers side and those clips need to be replaced. Has anyone else had this many issues with their trucks????