A: To start with, the process of loosening the Exhaust Manifold-to-crossover pipe retainer nuts here involves the crossover pipe and is used only in V-type engines. In most cases, flanged connections or collars join this pipe to the manifolds. However, there are occasions when bolts that are unthreaded for part of their length are utilized together with springs. When fitting a new pipe, it is important the springs are fitted and in good mechanical state (such as no broken coils). There is also need to replace ring type seals.