An exhaust-manifold gasket is more likely to need renewing than the gasket on the intake manifold, because of the greater damage caused to the exhaust system by heat; but the procedure is much the same for both. A 'blown' exhaust gasket can be detected by excessive noise from the exhaust, and by white burn marks around the manifold flange. Replacing manifold gaskets can be performed at home with a few simple tools. Before removing either manifolds, apply penetrating oil to all nuts or bolts which must be undone. When the nuts or bolts are removed, the remains of the old gasket may cause the manifold to stick: tap the manifold with a rawhide hammer to loosen it. If any manifold studs are broken or damaged, remove them using self-locking grips, two nuts and a spanner, or stud remover. After reassembly, run the engine to working temperature, switch it off and check the torque settings.