GM Service Manual Online
For 1990-2009 cars only

Engine Mount Inspection Engine Mount Inspection

Notice: Broken or deteriorated mounts can cause misalignment and destruction of certain drive train components. When a single mount breaks, the remaining mounts are subjected to abnormally high stresses.

Notice: When raising or supporting the engine for any reason, do not use a jack under the oil pan, any sheet metal, or the crankshaft pulley. Due to the small clearance between the oil pan and the oil pump screen, jacking against the oil pan may cause the pan to be bent against the pump screen. This will result in a damaged oil pickup unit.


    Object Number: 290320  Size: SH
  1. Raise and support the engine with a screw jack.

  2. Object Number: 307279  Size: SH
  3. Raise the engine in order to complete the following tasks:
  4. 2.1. Removethe weight from the mount.
    2.2. Place a slight tension on the rubber cushion.
    2.3. Observe the mount while raising the engine.
  5. Replace the mount if the following conditions exist:
  6. • Heat check cracks on the hard rubber surface
    • The rubber cushion is separated from the metal plate of the mount.
    • There is a split through the rubber cushion
  7. If the mount is loose, lower the engine and tighten the bolts or the nuts to the engine frame or the bracket.
  8. Push up and pull down on the transmission extension housing. Observe the transmission mount.
  9. Replace the mounting if the following conditions exist:
  10. • The rubber cushion is separated from the metal plate of the mounting.
    • The mounting has bottomed out.
    • The extension housing moves up but not down.
  11. If a mount is loose, tighten the bolts or the nuts that attach the mount to the transmission or to the crossmember.
  12. Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

    Tighten

        • Tighten the transmission mount to transmission bolts 55 N·m (41 lb ft).
        • Tighten the transmission mount to support nuts 43 N·m (32 lb ft).