That "new coffee pot" plastic taste.
Here's a useful bit of technology I discovered. Having bought a new coffee maker - a "Mr. Coffee" type drip machine - I found that it left the coffee with a nasty plastic taste. You could also smell the same plasticy aroma just opening up the packaging. I was advised that washing the coffeemaker and running a lot of water through it would cure this. Well, it didn't seem to.
Other suggestions included vinegar, powdered "coffee pot cleaner", and running it through the dishwasher (well, please don't run an electrical appliance through your dishwasher, OK?)
But I did have something on hand that eliminated the smell and taste completely - Vodka. Thoroughly moisten a paper towel with vodka (Everclear would work, too) - and wipe down all the interior surfaces (especially plastic ones). Mostly this means the water reservoir, the filter basket, and any lids. The glass carafe can be done, too. Use at least a shot or two of vodka. (Not counting that which you drink.) Follow with a thorough rinse.
Evidently the bad-tasting plastic residue is soluble in alcohol.