One problem related to engine knocking noise has been reported for the 2004 GMC Sierra 1500. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2004 GMC Sierra 1500 based on all problems reported for the 2004 Sierra 1500.
I own a 2004 GMC Sierra 1500 that is currently being repaired for cracks in both engine heads. The truck has 90,000 miles on it and I have kept up on all necessary maintenance. The problem began approx. 2 months ago when I noted a knocking sound after starting the truck cold. The knocking would dissipate after the truck warmed up. I was told the sound was caused from dirty lifters and not to be concerned as long as sound dissipated after it was warm. Upon having my oil changed 2 days ago, coolant was noted in the oil. (hints the knocking) the heads were pulled and both were cracked around where the heads bolt to the block. In talking to the mechanic, the cast they used when making the heads was bad. Apparently around the bolt holes, the aluminum is thin. GMC however accepted millions of these and are still using them today. The repair is costing me $3,400. 00.