2001 chevy pu on 1999 Chevrolet 1500 Pickup

Gentlemen: I have a 2001 Chevy P/U, 1500, 5.7 Engine, 2WD, Automatic Transmission. When it is below 40 degrees and I start it, it sounds almost like a diesel for the first 400 feet (approx.) then the sound goes away. Other than this problem it runs just fine. it doesn't make this sound when it is above 40 degrees. Any information or suggestions would be appreciated. Thank you. Don Geering

by in Broomfield, CO on April 17, 2009
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2 answers
ANSWER by , April 17, 2009
If your engine is making a knocking noise after a cold start chances are that the oil pressure is low. This could be caused by oil that is to thick, a worn engine or oil pump. Please have a qualified technician check the noise. If it is indeed an oil pressure issue you need to find out exactly what is causing the problem and then decide on the necessary repairs.
ANSWER by , September 16, 2009
with the aluminum heads and cast iron manifolds this sound is ''OK'' according to GM. Until the two heat up ull hear a knock....Ive also heard from other dealers that its piston slap,mass produced and not bored very well.