Audio Systems: FM Reception, gmc yukon, chevy trucks

Question
I have a 2004 GMC Yukon with the factory radio: am/fm/cd/xm
Lately the FM reception does not receive well while the engine is running; turn the engine off and the signal comes in fine. All other am/xm works fine with the engine running or not. I have tried a new antenna and that did not help. Can you please steer me in the right direction as to what the problem might be?

Answer
I hear a lot about this problem on 2003 to 2005  all gm ,Chevy trucks and they all share the same radio
i don't know for sure but i believe the radio is bad  almost all the people with this am/fm problems try to replace the antenna and it didn't help

take the radio to a repair shop and have them run a test on it