Engine Noise - Only when accelerating.

seat belt flapping in the wind, close the windows

 

how many miles on her?

 

see if the plastic panels are coming off or it could be a wheel bearing

 

I think i have the same sound on my 05, couldn't tell where the sound was coming from.

48mpg are you referring to the plastic panel under the car that extends to the front?

 

From that definition, it sounds possibly like detonation or pinging. One way to rule that out usually is by using a higher octane gas and see if the noise disappears. It could be from fouled spark plugs, bad gas, dirty injectors.

I've also heard someone mention that it could be the bearing on the water pump make a similar sound.

dave

 

motor mounts okay?

 

yes see if it moves

 

I suggest that you replace the cracked part, or try to seal the cracking using duct tape. That may be the cause of your issue.

 

Was this issue ever resolved? My 2009 is doing the same thing.

 

My 2007 is having the same symptom. Started after a long climb on a hill. If the engine RPM started to climb (on the high side, but not screaming), it sounds like a plastic bag flapping in the wind...but under the front of the dash (engine compartment). It is NOT a pinging sound. It only makes the sound when the rpm climbs up. So it is related to torque or RPM. I’ve never heard a sound like this before from an engine. Almost sounds like an exhaust leak...but it isn’t heard at lower rpms when we punch the throttle.

Craig

 

motor mounts okay?

 

I know this thread is old but my two cents today about this guys is that you're mistaking that sound for valve clatter, so look at other blog threads. As an old-school guy I was thinking the Prius was having bad valve guides but the problem according to other chat guys is the ports are getting clogged and therefore oil starving the valves, especially on acceleration. On old engines, American engines, once you had valve clatter you were not getting away with it for very long because the head would need to be rebuilt.

The other threads will describe using oil additives that act like cleansing hydraulic fluid, and we Old Skool guy used to use a quart of ATF automatic transmission fluid to clean out the ports and allow better oil porting to the top of the heads. These days, there are quite a few additives that can help achieve the same thing.

Posted via the PriusChat mobile app.

 

Hello guys,
Please help me i am having same hashing sound like when you put something in running fan. This sound appears only at high RPM if i reduce gas the sound is gone also engine vibration at some certain rpm / speed. Few days back i was having misfires and unfortunately my manifold. I also saw temperature light for few times it appears and gone when I reduced speed.
what i have done so foe is
Clean egr
Clean manifold
Clean catalytic
My manifold was burnt out so I replaced

 

Maybe it would be more helpful for you to post your questions in one of the Gen 3 forums.

 

Hi all sorry to jump on this thread, mine is doing the exact same thing, only at higher revs its doing this, what was the outcome for the issue and fix.
I took it to a garage to check the exhaust and then tried to show them the noise but I couldn't due to not being able to rev it this high

any help would be appreciated.

 

I can't see the OP's video on YT but it could be exhaust leaking out around your header/downpipe donut where the catalytic connects due to a clogged catalytic creating too much backpressure and resistance to flow.

How is your performance / top end right now? Are you struggling to hit 85-90+mph on the highway with the gas pedal to the floor?