Before removal and replacement of the gasket, check whether it's the flange or manifold gasket that has a leak. The exhaust manifold gasket repair process varies from car model to car model. It's also dependent on engine type.
Most engines are practically the same save for torque specs. Use your user manual to look up that info. Doing this job in a DIY fashion can save you from $150 to $800 depending on whether your vehicle is high-end or low-end. You'll need jack stands, a set of sockets, a set of wrenches, a scraper, and a screwdriver.
The Step-by-Step Process
- Negative Battery Cable and Jack Stands: When removing the exhaust manifold, you should first pull the negative battery cable from its terminal. Afterwards, set up the jack stands to raise the vehicle up while making sure that everything is securely supported. You might need to put up wheel chocks or rocks for good measure to keep your vehicle from rolling away.
- Multipart Car Part Removal: Remove multiple components to get to the manifold. Remove the gravel shield on the underside of your car as well. Loosen the bolts of the exhaust flange then remove that as well. This will give you access to the downpipe, which when removed will allow you to get to the manifold itself.
- Dealing with the Exhaust Manifold Itself: The manifold bolts should be unscrewed with 2-3 passes. Start at the center of either side of the manifold then work out a crisscross pattern of bolt removal. This will allow you to safely lift and take off the manifold. In most vehicles, pulling the manifold away from the engine should be easy as long as you have the tools to allow you to reach the bolts.
- Installing the New Intake and Exhaust Gasket: Before gasket installation, clean the debris and gasket material with solvent spray and a bottle of compressed air. Check if the surface has damage or none. Afterwards, remove the old gasket and install the new gasket before setting the exhaust manifold back into place altogether.
- The Correct Torque and Proper Reinstallation: In order to tighten the bolts, use the correct torque as specified by your car's user manual. Bolt tightening should follow the same crisscross sequence you did early in three passes. From there, install the downpipe and set the exhaust flange into position. Tighten the bolts of the flange as well. Afterwards, don't forget to put back the gravel shield you removed earlier too. Don't rush when reinstalling everything.
- Finishing Up Everything: You can now reconnect the negative battery cable in order to check if everything is working. Start your engine then check if there are any exhaust leaks left. Your new gasket should ensure that there are zero leaks. Finally, turn your engine off and lower your vehicle from the jack stands. You're all done!