Gen 2 Prius - Odd Noise Under Acceleration

[fuel miser]

I've had my recently acquired 09 (gen 2) T-Spirit for a month. On driving the car back from Derbyshire on the very day I bought it, I was aware of a rather odd noise which sounded like it was coming from the engine bay. Above 40mph, when one accelerates hard, there is a loud 'rasping/buzzing' noise being made. I know it's not normal as my 06 T4 has never made this racket, it's present all the time if you keep the throttle about 75% depressed and as the speed rises from 40 to 70mph and above. I immediately got the car serviced by Toyota and reported this problem to them, it was suggested I drove the car with a service engineer present, having done so and demonstrated this noise, their diagnosis was a dashboard rattle, and they would need the car for a day to sort it. I was just going away on holiday, so I have only been able to get the car to them last Wednesday.

I did discuss with them how surprised I was that they thought the noise was from the dashboard and not the engine bay, but they assured me it was a known problem and so the dashboard was duly dismantled and clips to the body and air vents were all replaced, and sealing foam applied before re-assembly.

So I collected the car on Thursday and drove it straight home, I didn't try and induce the noise (it's difficult to in a 30mph urban area) as I just assumed they would have sorted it. On Friday I didn't use the car at all. Yesterday (Saturday) I drove up to Harlow in Essex, a trip which takes me through the Blackwell Tunnel and up the M11. As soon as I joined the A2 at Kidbrooke and accelerated above 40mph, the noise is absolutely no different! :ffs: :censor:

Has anyone else ever experienced this with a gen 2 and remembers what it actually was? I'm keen to get it sorted (it's under warranty by the way) as it rather spoils the car, and as I mainly drive long distances up and down the country I can't avoid this annoying racket.

I do hope someone knows, since Toyota obviously don't!

[kithmo]

It could be an induction noise, a loose pipe or air filter box. Check all the tubes going to and from the air filter box for security and/or leaks.

[Jan&tone]

Hi there, I never noticed anything like that on my gen2, it was always very quiet.

[fuel miser]

I've just been for a lengthy run with another Toyota service engineer, took it on dual carriageway and again demonstrated the rasping noise on acceleration. He seems to think it may be a heat shield or the exhaust system making the racket, I'm taking it in again tomorrow and they may need it for a couple of days. He didn't, however, agree it was anything to do with the air-filter or any loose pipes. Hopefully this time they'll sort it.

[kithmo]

He didn't, however, agree it was anything to do with the air-filter or any pipes. Hopefully this time they'll sort it.

Is this the same guy who thought it was the dash ? <_<

[fuel miser]

He didn't, however, agree it was anything to do with the air-filter or any pipes. Hopefully this time they'll sort it.

Is this the same guy who thought it was the dash ? <_<

No, another one. I'm a bit miffed about it as I had stated from the outset that I was convinced the noise was coming from the engine bay. He agreed with me that it defo seems to be more from the drivers side, I hope that's enough to narrow it down for them! It also seems to be when the engine is at a certain 'pitch', so I've persuaded them to bypass the throttle !Removed! when the car is stationary, and therefore having the engine revving may induce the noise and make it easy for them to identify. Fingers crossed.

[fuel miser]

Just got my car back after Toyota have had it for two days, however, problem sorted!

It transpired to be pipes which were part of the air conditioning system vibrating against the bulkhead, but this only occurred when the engine was creating a particular resonance high up the rev range. I thought I'd report back on the outcome as when I tried searching for this problem, I couldn't find another case of it, so it might be helpful to someone else in future.

[Chris Dance]

Glad you got it sorted in the end.

[Abdullah2]

Did you're car made this sound?