How to Repair an Exhaust Manifold Leak

What You'll Need
Rubber hammer
Replacement Gasket
Safety gloves

With an internal combustion engine, you may find that you develop an exhaust manifold leak. The manifold is the part of the car that keeps the gases from leaking back into the car, so if you have a hole, or other problem in your exhaust manifold, you are actually leaking toxic fumes back into the body of the car. This can be very problematic, and you will need to repair it as quickly as possible in order to prevent damage to your car, the catalytic converter, or any other part of the vehicle. In order to prevent further damage to your car, you need to fix that leak quickly and simply.

Step 1 - Check the Leak

Before you can begin to work on the leak, you will need to check your engine, including the exhaust manifold area, to ensure that there are no further leaks which need to be repaired. You should also look under the bonnet to check that oil is not leaking into the manifold. When looking for these kinds of problems, the manifold will need to be as cool as possible, and you should leave it parked, with the engine turned off, for about 2 hours before you proceed. Be careful when you touch the manifold, as they can become very hot. If you are not sure when the car was last used, but need to work on the exhaust straight away, put on a pair of safety gloves.

Step 2 - Remove the Bolts

Once you are ready, and have located the leak, you can begin to extract the manifold. Take off the bolts that keep the manifold in place. You will need a wrench to unscrew these bolts, as they hold the exhaust manifold onto the head of the engine, and so have to be tight. Look for two large bolts, one either side of the manifold.

Step 3 - Remove the Manifold

Unscrew these bolts and then pull the manifold away from the body of the car. You may find that it becomes stuck, or won't shift. In this case, you should strike the top of the exhaust manifold with a rubber hammer. The hammer has to be rubber, or you run the risk of harming the manifold. You should also avoid taking the manifold out of the engine completely, as this would involve disconnection it, and could be a long job.

Step 4 - Replace the Gasket

Once you have freed the manifold, take off the gasket by sliding it towards you. You may need to hold the gasket with a rag or piece of cloth in order to get a proper grip on it. These are the parts most likely to leak, but you should examine the rest of the manifold for damage at the same time. Fit the new gasket by pushing it into the cylinder head.

Step 5 - Refit the Manifold

After you have replaced the gasket, you can screw the manifold bolts back into place, and tighten until the bolts are holding the exhaust manifold tightly onto the car engine.