TSB's

Ticking cylinder head

This concern applies to a variety of GM vehicles equipped with the 2.0L LSJ, 2.0L LNF, 2.2L L61, 2.2L LAP, 2,2L LE8, 2.4L LE5, 2.4L LE9, 2.4L LAT and 2.4L LAF engine (vehicles include Buick Regal and LaCrosse, Chevy avalier/Cobalt/Equinox/HRR/Malibu, GMC Terrain, Olds Alero, Pontiac G5/G6/Grand Am/Sunfire/Pursuit/Solstice, Saturn Aura/Ion/ L Series/Vue).

A ticking noise at the cylinder head may be heard, which may be traced to a loss of oil pressure. The concern may be caused by debris clogging the oil feed restrictor in the cylinder head passage. The oil feed hole has a small inner diameter and may clog if debris or excessive RTV/sealer has dislodged and has become stuck in this passage. Whenever RTV (or other gasket sealer) is used, care must be taken to avoid excessive amounts that can become dislodged. This restrictor is located in the oil feed passage to the cylinder head and cannot be inspected or cleaned without removal of the cylinder head. Note: per typical GM policy, the restrictor is not available separately from the cylinder head.

To diagnose this concern, use a mechanical oil pressure gauge. Check and compare oil pressure in the block with oil pressure in the cylinder head. The block can be checked by removing the oil pressure sender. The oil pressure in the cylinder head can be checked by removing one of the oil galley plugs in the head. If no oil pressure is evident in the cylinder head, the head must be removed and thoroughly cleaned. Inspect the valvetrain for wear/damage and repair as necessary.

The oil restrictor (2) can easily become plugged with debris. Removing one of the oil galley plugs (1) allows oil pressure gauge testing.
<p>The oil restrictor (2) can <em>easily</em> become plugged with debris. Removing one of the oil galley plugs (1) allows oil pressure gauge testing.</p>

 

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