Some 04 XLR , SRX with the 4.6L LH2 Engine Cold Start Moan Noise - kw front cover oil pump gasket whine

The following diagnosis might be helpful if the vehicle exhibits the symptom described in the PI.

Some 2004 XLRs and SRXs equipped with the LH2 Northstar V8 engine may have a noise complaint on a cold start. The noise is described as a moan type noise. The noise level diminishes as the engine reaches operating temperature. When diagnosing the source of the noise it sounds like it's coming from the front cover/ harmonic balancer area.

Replace the engine oil pump. There is a revised oil pump to correct this condition. The new part number for the oil pump is 12590890. This new pump was put into production starting in late April 04 at ENU L041140223 Note: If the original front cover gasket is of the paper variety, then a new front cover must also be ordered. A new front cover is required to be compatible with the new front cover carrier type gasket.

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Please follow this diagnosis process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed. If these steps do not resolve the condition, please contact GM TAC for further diagnostic assistance.

(2004 Cadillac XLR, SRX with the 4.6L LH2 engine)

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