When I start the Blazer, especially when it is cold, I notice a clunk. I bought it with 50K miles so I wonder if it always did that, maybe just the nature of the beast. I had a Ford that did that (though much worse) and it turned out to be faulty motor mount.
Might be my technique, maybe I release the key too soon. Is a clunk on starting normal? Thoughts?

 

I've never noticed any clunks when I start mine. Have someone else crank it up while you look under the hood. Check or any abnormal engine movements to determine if you have a bad motor mount. Also, while standing to the side, have your helper put the truck in drive, firmly plant their left foot on the brake, and slowly rev the engine. See if the engine moves up and down

 

 

Driving today paid attention and I would say it's more of a jump than a clunk. I'll try those tests and see what happens