> erik, > There are two possible causes for the noise that you describe. Pre-ignition > commonly called "pinging" (rare in DeLorean's) it is a serious condition > that could cause serious harm to the internal engine components. > > It could also be an exhaust gasket leak. If it's the gasket it won't effect > engine operation, it just sounds bad. There is a third possible cause. There is a metal heat shield rivited on the top of the cross over pipe. It is not unheard of to have the rivets loosen up to the point that the metal shield rattles when the engine is revved to any sort of RPMS. Bruce Benson