Newer Bowser Executive line, sorry! Will edit original post!
Isaac,
Perhaps a good cleaning and/or some light lubrication would be a good place to start. Sometimes locomotives do arrive dry because the factory forgot to lube them. And sometimes they come over-lubed, which poses it’s own issues. It also depends how long a locomotive sits on the shelf and/or under what conditions.
Tom
Yeah, I’m sure the issue could be figured out if someone would really take a good look at them. However, as I previously stated they are my grandpa’s models and are at his house quite a ways a way from where I am right now… so not much I can do right now… perhaps I’ll take a look next time I visit!
That Bowser LV F unit is very well done. I almost bought one…had it set aside at a dealer. It will run well, look good, and be a very reliable engine. You won’t have to worry about any details falling off, as most are actually separately applied metal (brass castings and wire grabs).
John
I have only one BLI diesel, Sheldon - a NYC SW7 - and it has nice detailing. I don’t own any Bachmann locomotives so I can’t really comment on whether it has better or worse detailing than BLI. I do think that Bachmann offerings tend to be less prototype-specific than BLI.
Other than the SW7 that I picked up on eBay 2-3 years ago, I haven’t purchased a BLI locomotive in nearly 10 years because they have not offered anything of interest for me and the prototype I model. And I don’t expect that to change with Bachmann either.
Tom
I have an A-B set of Bowser F7s and am very happy with them for detail, running characteristics, etc. Can’t comment on sound as one is silent and one has a sound decoded with no speaker (yet). 
I also own three Bowser Alcos and have had trouble with detail parts falling off (sometimes before they arrived to me!) but that wasn’t a problem with the Fs. I do wish the packaging didn’t have those silly screws… they seem to forget that some of us like to store our locomotives in the boxes.
I own a couple of Genesis units (not Fs) and am happy with them. My fellow clubbies have plenty of Genesis Fs and are happy as well.