I have 2001 Silverado with an ANNOYING buzz/grind. It worse when it’s cold on startup. It seems to be some type of vibration that happens under load. It’s an automatic. In 1st, under normal driving, the “grinding” is from about 800 to 1000 rpm, in 2nd and 3rd it happens when the tranny shifts up or down and the rpm is in that range.
If I’m stopped and in neutral, it makes the noise, but much softer. In gear with the brake engaged, it’s loudest at about 900 rpm.
Any ideas what this could be. My mechnic said it could be just about anything which didn’t help much.
Thanks for your help!
Rob
This is a long shot. I had a similar noise (grinding) in a 2000 S-10 Blazer. It was most noticeable during acceleration. It got worse after the intake manifold gasket was replaced.
Looking under the dash the noise was coming from the accel pedal cable. I trace the cable under the hood and found one of the tie down point for the cable was broken. I fixed it with a tie wrap, the noise is still present during acceleration but is much more subdued. Since I know the noise is not due to a mechanical problem I don’t worry about it.
Ed B.