a dirty engine bay after swap is sign of charsi mechanic and lazy owner
i can see you left it to mechanic to wash & clean the engine bay and he skipped it. TOLD you to ensure its done before engine is moved in . - now you need to do it yourself 1 sachet of any shampoo in 1.5 liter of water be mixed n sprayed over engine bay i suggest remove the hood do it over cold engine and left for 10 minutes before washing with clean water blow dry the engine.