I recently had the water pump and serpentine belt replaced. And ever since that I am hearing a hissing sound only when accelerating. The mechanic says he doesn’t know what it is. Hum, can you help? Oh, my car is a 2007 Honda civic ex.
I would suspect that you have a vacuum leak.
Also check the big black corrugated hose that carries air from the air filter to the throttle body.
These can crack at those ribs. Be sure to check it carefully, the crack could be hidden.
Yosemite
If the serpentine belt tensioner wasn’t replace when the water pump/serpentine belt was replaced, that’s where the mechanic made their mistake.
https://www.rockauto.com/en/catalog/honda,2007,civic,1.8l+l4,1434324,belt+drive,belt+tensioner,11659
Tester
Say Yosemite, thanks for responding. I kinda think it may be a vacuum line too. But do you know off hand if there are any vacuum lines or hoses that could have come off near where the water pump job was done?
Does it make this noise if you rev the engine in neutral/park?
hey circuit, no, it only seems noticeable when im accelerating. and it seems to be coming from passenger front of the car. but noises and where the are coming from can be deceiving. thanks for responding
A vacuum leak would hiss at idle.
A belt tensioner would make noise revving in neutral/park or under load (accelerating).
It could be a leak in the hose from throttle body to air filter.
It could also be an exhaust leak, or even coming from the transmission.
if it was a transmission issue, do you think it could be a vacuum hose that may be disconnected