03 Silverado Awful Startup Noise, possible piston slap but I think it's worse?
April 19th, 2018, 4:14 PM
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03 Silverado Awful Startup Noise, possible piston slap but I think it's worse?
Hi all, I have an 03 Silverado, 5.3l V8 Gas engine. On cold startup, after sitting overnight or longer, it makes a horrendous slapping sort of noise. My immediate assumption was that it is a piston slap, but it sounds so awful sometimes I wonder if it's something worse, and idk what a piston slap sounds like. The engine takes a lot of coolant, maybe a gallon a year, I've changed the plugs and there was no white/sign of coolant in the cylinders. Also had a hydrocarbon test done and returned no results of coolant in the oil. Any ideas? Below is a video link to the noise, in the video it is at a medium-volume compared to what I've heard in the past. It can be double the noise and intensity at times.
April 29th, 2018, 6:27 AM
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Sounds like the normal piston slap on my 01. Not sure about the coolant issue. Mine leaked from a bad radiator; replaced that. Also leaked from a bad water pump; replaced that. Check both those things. Just let the slap-sound go away (oil getting throughout the motor) before you rev it and drive.
April 30th, 2018, 11:34 AM
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Sounds like piston slap to me.
My 00 5.3 does that when it's colder. I've put remote start on it so I typically start it 1 or 2 min before I even get to the truck.
My 00 5.3 does that when it's colder. I've put remote start on it so I typically start it 1 or 2 min before I even get to the truck.
