chug chugchug chugchug mmmoooosh
sound of a steamroller (Diggers go by Steve Light. All caps in the book CHUG CHUGCHUG CHUGCHUG MMMMOOOOSH)
RRUUMBLE SCRUNCH SCRUUMBLE SCRUUUNCHH
Sounds made by a bulldozer. From: 
construction equipment machine heavy engine
skwee brrumm brrumm skoooooo skooooo
Sounds made by a front loader (Diggers go by Steve Light, all caps in the book SKWEE BRRUMM BRRUMM SKOOOOOO SKOOOOO)
engine rubble sand stone dirt metal
Search tips:
- Fewer searchterms (eg. cat will yield more results than cat sounds)
- Try synonyms (eg. if saber does not give you results, try sword, cutlass or blade)
- Truncate (eg. walk will give more results than walking because it returns everything that has walk in it including walked and walks)