Hi

I have noticed at low revs when pulling away a squeal, garage have replaced a belt tensioner and are now saying it could be the air conditioning pump but if I have the cvt transmission in neutral or park and gently rev the engine there is no noise.?

car as done 40k and drives perfectly 

Any thoughts?

 Thanks 

 

I think if it was a belt it would most definitely squeal on start up
Belt tensioners can also cause this sort of noise but most generally a squealing belt is down to the make (or most importantly where it is made) and doesn't contain much rubber content, more of a synthetic silicon material which will squeal and stretch no matter how much you tighten it over time