How to Repair Leaking Intake Manifold Gaskets

by David Marsh

After the fuel/air mixture leaves the carburetor, it flows through long passageways inside the intake manifold. The mixture runs into the cylinder head, sitting atop the engine block. When the intake valve is closed, the mixture inside the intake manifold passageway becomes backed up and pressurized. There is a gasket between the intake manifold and the cylinder head which must withstand all of the pressure as well as heat from the engine block. Getting to the gasket will take some time because the cylinder head has to come off, which includes removing the carburetor, disconnecting the radiator hoses and all the other hoses and wiring.

Look on the intake manifold manufacturer's website or their literature for approved gaskets.

Remove all grease and dirt from the cylinder head intake flanges and the engine block end seal surfaces.

Coat the cylinder head side of the gaskets and the cylinder head flanges with gasket sealant. Let it air dry and put the gaskets in place

Squeeze a quarter inch bead of silicone sealer across each block end seal surface. Take care to overlap the intake gasket at the corners. This stops end seal slippage.

Install the intake manifold and tighten the bolts holding it against the gasket and cylinder head. For engines built before 1995, remember to put sealant all around the inner eight bolts. The bolt holes under the inner bolts aren't blind holes. Tighten the manifold completely following the instructions for torque and tightening sequence given by the intake manifold manufacturer.

Items you will need

About the Author

In 1990 David Marsh began writing a column in the "Idaho Falls Post-Register" titled "Good Things," which presented restaurant reviews, sports analysis and movie criticism. Besides newspaper columns, Marsh researched police procedures for the Federal government. He has a Bachelor of Arts in administration and a Bachelor of Science in journalism from the University of Utah.

Photo Credits

  • photo_camera New car petrol engines image by Christopher Dodge from