For 1990-2009 cars

Important:

• | Read the entire procedure before removing the camshaft housing.

• | The camshaft housing to the cylinder head gasket must be replaced any time the camshaft housing to the cylinder head bolts are loosened or removed.

• | During disassembly, be sure that the valve lifters are kept together and identified in order so that the valve lifters may be reinstalled in their original locations.

1. Remove the exhaust camshaft rear cover.
2. Remove the exhaust camshaft rear cover gasket.

Important: Use the reverse of the tightening procedure when loosening the camshaft housing to the cylinder head retaining bolts.

3. Remove the exhaust camshaft housing to the cylinder head bolts.

Important: Leave 2 bolts loosely in place to hold the camshaft housing while separating the camshaft cover from the housing.

4. Push the cover off the camshaft housing by threading four of the housing to the head retaining bolts into the tapped holes in the camshaft cover.

Important: Tighten the bolts evenly to prevent the cover from binding on the dowel pins.

5. Remove the two loosely installed camshaft housing to the head bolts.
6. Remove the camshaft cover. Discard the seals.
7. Loosely install one camshaft housing to the cylinder head bolt to retain the housing during the camshaft and lifter removal.
8. Remove the camshaft. Be careful not to damage the camshaft or journals.
9. Remove the valve lifters. Keep the valve lifters in order so that the valve lifters may be reinstalled in the same location from which they were removed.
10. Do one of the following to minimize lifter bleed down:

• | Store the lifters upside down on a level surface. Keep the camshaft contact surface down.

• | Store the lifters submerged in clean engine oil.

Important:

• | The valve lifters are not repairable. Replace the lifters if the lifters are faulty. Do not get prelube on the camshaft cover seals because the seals will swell.

• | Coat the lifter with Camshaft and Lifter Prelube GM P/N United States 12345501, GM P/N Canada 992704 or an equivalent before installation.

11. If new lifters are installed, add Engine Oil Supplement GM P/N United States 1052367, GM P/N Canada 992869 or an equivalent to the engine oil.
12. Remove the camshaft housing.
13. Remove the camshaft housing gasket.