I don't think this is about the Decepticons looking for something... I think it's something they wanted to hide.
Read more Simmons QuotesFrom: Transformers: Dark of the Moon (2011)
Lennox : Why was he after this?Optimus Prime : It's impossible... This is an engine part, from a long lost Autobot ship.
Simmons : [about Carly] She lives here? Wow!Simmons : You had your chance to frisk her.Dutch : I have a girlfriend.Simmons : Really, what's her name?Dutch : India...
: Years from now they're going to ask us: where were you when they took over the planet? We're gonna say: we stood by and watched.