Identifying an exhaust manifold gasket leak can be very easy if ticking is present, and plenty of exhaust gas is making a stink at the engine, but minor leaks can be tricky. Ordinarily, the vehicle will be raised, and the intake manifold will be inspected for signs of leakage, such as black marks, and burned non-metallic components around the exhaust manifold. If there are no signs, the exhaust may be smoke tested, or plugged to make leaks more apparent.
How is an exhaust manifold gasket replaced?
Exhaust manifold gasket replacement only requires the manifold retaining hardware to be removed, the old gasket removed, and all mating surfaces cleaned thoroughly. If the manufacturer specifies sealant, it is applied to the gasket, otherwise the gasket is placed on the exhaust studs. The exhaust manifold will slide in place on the gasket, and the technician will torque new exhaust manifold retaining fasteners to factory specification.
RepairPal Recommendations for exhaust manifold gasket issues
As manufacturers spend millions of dollars designing the perfect exhaust system for their engines, we recommend using at least OEM quality parts, if not parts from the OEM.
What to look out for when dealing with exhaust manifold gasket issues
The exhaust system operates at extreme temperatures, so metal becomes brittle after a long service life. Fasteners need to be replaced when an exhaust manifold gasket is replaced as the old bolts are unreliable, and the fasteners may be destroyed during removal.
Can I replace the exhaust manifold gasket myself?
Replacing an exhaust manifold gasket is only a DIY capable project if the leak can be positively diagnosed at home, and when caught early. If caught late, the exhaust valves must be inspected by a trained professional technician. If any welding is required, a professional exhaust welder should complete the repair.