First, I have searched for about an hour and have not been able to find a situation similar to mine.

Ok so if I am at a light I can hear the pump whine. No problem. All Wahlbro pumps whine, but what sounds weird to me is if I just barely touch the gas and let go (shoots up to about 1500 rpm) when the rpm's drop back down the pump whines at a higher pitch for about 2 seconds then drops back down to the normal whine sound. I just noticed this yesterday and have not heard it in the past.

My question is if this is still normal operation of a Wahlbro or should I just replace the unit to be safe?

Thanks for the help in advance.

 

I have one and it doesnt whine, I would call the company. They will probly change it for you as long as you just put it in.