ORIGINAL: RCKen
2.4 Ghz radios can still be affected by RF interference like this. Unfortunately many people are confused on this issue. 2.4 radios will not interfere with EACH OTHER, but RF interference can still affect them. Metal to metal contact can/will vibrate with the engine running and cause glitches in your radio that you are describing.
Ken
Spektrum says opposite of that.
http://www.spektrumrc.com/DSM/Technology/spekTech.aspx