hi guys wondering if any one could help i have a odd sound coming from the engine bay which sounds like its exhaust is loose but its not. I turn the engine over and after about 10 seconds the noise kicks in. only when you go the sound goes i decided to take air pipe off and put my hand over the hole and the sound stops but it sucks my hand in obviously so i have ti lift it off. thinking faulty maf i have no idea ??