Cylinder Head Distortion

WARNING: This page is about a different car, the 2005 Mercury Sable and 2005 Ford Taurus. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Make sure all cylinder head surfaces are clear of any gasket material, RTV, oil and coolant. The cylinder head surface must be clean and dry before running a flatness check.

NOTE: Use a straightedge that is calibrated by the manufacturer to be flat with 0.005 mm (0.0002 in) per running foot length. For example, if the straightedge is 61 cm (24 in) long, the machined edge must be flat with 0.010 mm (0.0004 in) from end to end.

Fig 1: Inspecting Cylinder Head For Flatness

Courtesy of FORD MOTOR CO.

Using a straightedge and a feeler gauge, inspect the cylinder head for flatness in the sequence shown. If the cylinder head is distorted, install a new cylinder head.