flintlock
Newbie
Hey guys, I have a 1997 k1500 cheyenne 4.3 nv3500, I got the truck 2 years ago this month. When I got the truck it had 196,000 miles on maybe original motor. I noticed from the bat a light knock heard moreso on the passenger side. Changed the oil with 10w40 and lucas additive. Noise mostly goes away until the oil breaks down and gets thin. Ive driven the truck over 15,000 miles and do not baby it but Im also not hard on it at all. I'm assuming this is a rod bearing knock. It goes away with increased rpms. It isnt a ****, ****, **** noise more of a **** ****....****...**** **** ****...**** ****...**** noise. Upon startup when warm, it makes a dunkah, dunkah, dunk noise same sound and pitch. This noise is only heard when the oil is hot. The truck holds good oil pressure, 60 at start up 30+ crusing down the road at operating temperatures and 20 at warm idle. What do yall think? I'm starting to believe it is not a bearing knock. I've accelerated over 3000 rpms many times and I have red lined it in neutral once or twice for giggles and my mechanic squalled tires once. I would assume it would have spun a bearing and locked up by now, or are Chevys this tough? Lol
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