2011 Silverado z71 Shudder/Shake

[TheWaltWilson]

My 2011 Silverado z71 has started shuddering/shaking whenever I am braking or accelerating but ONLY at really low speeds when I am almost stopped or just starting to accelerate. It doesn’t feel as if the entire truck is shaking, just the front (hood and engine area). The truck feels sluggish at times when I am driving but it shifts smoothly and has no offer issues. I did have a odor yesterday after driving it. The odor was in the cab. Not unpleasant smelling just a new odor. Ideas and/or thoughts? It doesn’t do it all the time. It’s almost as if the longer I drive it is when it starts doing it. But the sluggish feeling is always there lately.