I assume you probably have followed most of the recent water pump posts and threads, so I won't go into details except to say I live in Phoenix area. My local shop gave me a quote for the WP change, but said they would not do the job. I had a lead on a GM dealer with a quote of nearly the same money. The WP and thermostat were changed by the dealer, but I came away with a whine in the engine ..... new sound that had not been there. Ultimately the whine did go away, and I THINK I'm OK. But I had a lot of images in my brain like you just fixed. The dealer said bring it back and they would listen for the whine, which admittedly was not there now. To take it back was fruitless and the service manager admitted such.
Through the forum knowledge and sharing that with the dealer, the dealer learned a lot about the thermostat change, and admitted they did NOT know such prior.
I'm glad for you that you got your Kappa back on the road and running like normal.....a great feeling!! My car's performance was never an issue.