GM Service Manual Online
For 1990-2009 cars only

General Information on Engine Service

Caution: Before removing or installing any electrical unit, or when a tool or equipment could easily come in contact with "live" or "hot all the times" exposed electrical terminals, disconnect the negative battery cable to help prevent personal injury and/or damage to the vehicle or components. Unless instructed otherwise, the ignition switch must be in the OFF or LOCK position.

Caution: Before servicing any electrical component, the ignition and start switch must be in the OFF or LOCK position and all electrical loads must be OFF, unless instructed otherwise in these procedures. If a tool or equipment could easily come in contact with a live exposed electrical terminal, also disconnect the negative battery cable. Failure to follow these precautions may cause personal injury and/or damage to the vehicle or its components.

Notice: The following information on engine service should be noted carefully, as it is important in preventing damage and contributing to reliable engine performance.

When jacking or supporting the engine for any reason, do not use a jack under the oil pan. Due to the small clearance between the oil pan and the oil pump screen, jacking against the oil pan may cause the oil pan to be bent against the oil pump screen resulting in a damaged oil pump screen or oil pump pipe. A damaged oil pump screen or oil pump pipe could cause low or no oil pressure and cause extensive damage when the engine is started.

Any time the throttle body or throttle body air inlet tube is removed, the intake opening should be covered. Covering the opening will protect against the accidental entrance of foreign material which could follow the intake passage into the cylinder and cause extensive damage when the engine is started.

Notice: Pull on the spark plug boot, the heat shield or use an approved spark plug boot removal tool, twisting a half-turn to release the seal while removing. Do not pull on the spark plug wire or it may be damaged.

Notice: Clean the spark plug recess area before removing the spark plug. Failure to do so could result in engine damage because of dirt or foreign material entering the cylinder head, or by the contamination of the cylinder head threads. The contaminated threads may prevent the proper seating of the new plug. Use a thread chaser to clean the threads of any contamination.

Notice: Allow the engine to cool before removing the spark plugs. Attempting to remove the spark plugs from a hot engine may cause the plug threads to seize, causing damage to cylinder head threads.