Bought a used Honda Jazz under less than a month ago and now it's making noise

[carproblems123]

I bought a 10 year old automatic Honda Jazz from a dealer less than a month ago and noticed a humming / buzzing noise. Service history is there and no advisories in MOT history. The dealer couldn't find what it's caused by, there are no faults at the computer and he is going on about how reliable these cars are and how expensive to investigate etc. I would really appreciate some advice because I don't have much experience with dealers or second hand cars. One side of me wants to get rid of it, the other one doesn't want to fight with the dealer, it's so annoying

Is it when you accelerate or all the time?

I have a 14 year old jazz cvt and it makes exactly the same noise, it's just age-related as far as i know and common in cvt.

It seems to coincide with acceleration at low speed, below 25 mph

I’ve had similar on an automatic. My mechanic tightened up everything as it was a vibration coming from the engine area and it cured it.