Revving engine when stopped

No not yet. A friend of the family, who worked on it alongside others at the shop, took a look at it and said its the battery cable thing but it seemed like he only said that because he was complaining about how much work it would be to take out all the other stuff to look at the gasket (which my dad, a mechanic, said it might be). He wanted me to buy the battery head and he would replace it, but both of them are fairly new. I dont think thats the real problem. I dont want to keep spending money on guesses. But Im planning on taking it back tomorrow to the shop owner and have him look at it. Ill ask him to look at the vacuum. Thank you so much.