Hello,
On my 2007 Hummer H3 I have a strange rumble/rattle sound. It happened when the engine is cold and I put my foot on the brake and shift into reverse. As I reverse, it makes the sound for about 10-20 seconds and then its gone. I usually do not hear it once the engine is warm. Any ideas of what it is? I do not think that it is the heat shield. Have had heat shield issue on our other hummer and it only was only an issue during acceleration and rough idles.
On my 2007 Hummer H3 I have a strange rumble/rattle sound. It happened when the engine is cold and I put my foot on the brake and shift into reverse. As I reverse, it makes the sound for about 10-20 seconds and then its gone. I usually do not hear it once the engine is warm. Any ideas of what it is? I do not think that it is the heat shield. Have had heat shield issue on our other hummer and it only was only an issue during acceleration and rough idles.