A leak on an exhaust manifold can be welded, or depending on the severity of the damage, result in having the unit replaced. Small cracks are patchable, but large cracks require more extensive repair.
The exhaust system begins at the manifold. When the manifold is damaged, the engine sounds louder, releases poisonous gas into the air and often results in poor fuel economy.
Small cracks can be welded shut. Although this is still considered a temporary fix, proper technique will extend the lifetime of the weld. The following instructions explain how to properly patch a smaller crack.
- Remove the manifold The manifold mounts to the head of the engine. Loosen and remove the bracket bolts as well as the nuts that secure it to the top of the engine.
- Clean the manifold Once the manifold is off the car, use a lint free cloth to clean the damaged area. Be sure to wipe any debris off to avoid ruining the weld.
- Begin to solder Set the oxy-acetylene torch to low heat and begin filling the crack.
- Finish soldering Finishing filling the crack and let the manifold naturally cool off. Once it cools down, check for any obstructions inside its ports and mount it back to the engine.
When the crack is too severe on the manifold, the structural integrity is compromised. This results in the welds braking. In these circumstances, the exhaust manifold must be replaced by a professional.