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.
Notice: Do not remove the pigtail from either the heated oxygen sensor (HO2S) or the oxygen sensor (O2S). Removing the pigtail or the connector will affect sensor operation.
Handle the oxygen sensor carefully. Do not drop the HO2S. Keep the in-line electrical connector and the louvered end free of grease, dirt, or other contaminants. Do not use cleaning solvents of any type. Do not repair the wiring, connector or terminals. Replace the oxygen sensor if the pigtail wiring, connector, or terminal is damaged. This external clean air reference is obtained by way of the oxygen sensor signal and heater wires. Any attempt to repair the wires, connectors, or terminals could result in the obstruction of the air reference and degraded sensor performance. The following guidelines should be used when servicing the heated oxygen sensor:| • | Do not apply contact cleaner or other materials to the sensor or vehicle harness connectors. These materials may get into the sensor causing poor performance. |
| • | Do not damage the sensor pigtail and harness wires in such a way that the wires inside are exposed. This could provide a path for foreign materials to enter the sensor and cause performance problems. |
| • | Ensure the sensor or vehicle lead wires are not bent sharply or kinked. Sharp bends or kinks could block the reference air path through the lead wire. |
| • | Do not remove or defeat the oxygen sensor ground wire, where applicable. Vehicles that utilize the ground wired sensor may rely on this ground as the only ground contact to the sensor. Removal of the ground wire will cause poor engine performance. |
| • | Ensure that the peripheral seal remains intact on the vehicle harness connector in order to prevent damage due to water intrusion. The engine harness may be repaired using Packard's Crimp and Splice Seals Terminal Repair Kit. Under no circumstances should repairs be soldered since this could result in the air reference being obstructed. |
Notice: Modifications made to the following can affect the vehicle's emission
controls and may cause the Malfunction Indicator Lamp (MIL), Check Engine
or Service Engine Soon lamp to illuminate:
• The engine • The transmission • The exhaust • The fuel system
