hi there i have a vw golf mk4 1.6 8v one day i pulled off at the lights took the car upto abot 4500 rpm went the front wheels slipped on a drain cover i herd a loud bang and the engine sounded like i had removed the air filter (very loud) there was no smoke trail behind me, i pulled over to check and noticed the upper inlet manifold had been forced apart, the engine was idling erratically and making a popping sound which i think is a backfire into the inlet manifold, any ideas what could be the cause of this? looking forward to your reply thanks