Agreed. Not normal, though rust coloring (not the chunks) can be normal depending on the cleaning method used. I would first ask the builder (in writing by email or FAX) what to do about it. Hopefully you'll get some good advice and maybe some credit for basic work not done. It also serves to establish events in-case other stuff is weird. Sometimes it's skipped by accident and others on-purpose, but it nearly always leads to cooling issues either due to crap in the cooling and heating systems, or the crud still stuck in there insulating the block from the coolant for poor heat transfer. It's hard to tell with one little photo how much adhered buildup there is, but heat does not travel through rust and mineral buildups very well. We see a lot of that on here with non-functional heaters, overheating engines, and general misery at least partly due to poor cleanouts.
It's not a show-stopper, but depending on the answers, continue with FE's suggestions. Be sure to seal-off open areas to keep dust and crap out during the cleaning. In-fact, I would seal-off everything, then open the deck coolant holes, pull the core plugs, flip it over and start blowing with an extended nozzle. A little rod action may help loosen sediment layers and knock looser chunks off. It's a bummer, and extra work for you, but you'll end-up fine. Good luck!
:bicker:
David
