Head Torque Specifications for a Ford 3.8by Anne Davis
Ford introduced the 3.8-liter V6 engine, also known as the Essex because it was manufactured at the Essex Engine Plant in Windsor, Ontario, in 1982. This 90 degree engine was first placed in the Ford Granada, but was later placed in minivans, large cars, and certain pickup trucks. Ford ceased production of this engine in 2007 when its Cyclone engines gained popularity.
In an engine, the cylinder head, also known simply as the "head," sits atop the cylinders on the cylinder block. The apparatus consists of a platform that includes valves and spark plugs.
Torque refers to the force required to rotate an object, in this case a nut or a bolt, around an axis or pivot. You can think of it as a twist. Some components, especially involving the cylinder head, utilize a helical sequencing for torquing. For this sequence, begin torquing with the center-most bolt and work outward in both directions evenly. If there are multiple steps, torque all of the bolts to the first requirement, then torque all of the bolts in the same order to the second requirement, and so on. Wait about 15 minutes between each step to allow the bolts to stretch and settle before applying more torque.
For 3.8-liter engines manufactured from 1994 until 1995, the cylinder head requires multiple steps in a helical sequence to bolt properly: first to 15 foot-lbs. of torque, then to 29 foot-lbs., and finally to 37 foot-lbs.. Loosen the long bolts to between 29 and 37 foot-lbs. of torque and the short bolts to between 7 and 15 foot-lbs. of torque. Then, tighten each bolt an additional 90 degrees. The last two steps--the loosening and then the 90 degree tightening--should both be performed on each bolt before moving to the next bolt.
In 3.8-liter engines manufactured after 1996, the cylinder head bolts require multiple steps performed in a helical sequence: first, they must be torqued to 15 foot-lbs., then to 29 foot-lbs., and finally to 36 foot-lbs. Loosen the long bolts to between 29 and 37foot-lbs. of torque and the short bolts to between 11 and 18 foot-lbs. of torque. Then, tighten each bolt an additional 180 degrees. The last two steps--the loosening and then the 180 degree tightening--should both be performed on each bolt before moving to the next bolt.
Anne Davis writes pieces on domestic and international travel, automotive maintenance, education and health. She graduated with a Bachelor of Arts in English and history, and is pursuing graduate study in a related field.