Noisy engine

<div class='quotetop'>QUOTE(Ozymandias @ Feb 23 2007, 08:07 PM) [snapback]395608[/snapback]</div>

Mine has a knock to it also most of the time, not quite as much as diesel.

I noticed the test drive cars had this sound so I'm not too worried.

Yes, when it revs up it's pretty loud, check out the dynamat posts

 

The engine noise on acceleration is normal. You will notice that it is not directly related to the amount of throttle you apply. The Ice is running at its top speed to drive the car as well as provide electrical energy to the motors. I’m not sure if it is reduced during break-in or is just less noticeable with time. If it is noticable at a stop light there is a problem.

 

I can't agree that "sounding almost like a diesel" is normal. There is some noticeable noise when accelerating hard from a dead stop and it revs high but if it sounds like it's knocking or chugging like a diesel I would be concerned. I would never describe the Prius as noisier than a typical 4 cylinder. Maybe different but certainly not louder.

 

<div class='quotetop'>QUOTE(Ozymandias @ Feb 23 2007, 11:57 PM) [snapback]395632[/snapback]</div>

1.5L 4cyl is not the quetest engine. If it fairly quite on idle when you are inside the car. When you are standing outside next to it, it is fairly noisy. Not the diesel knocking type though, just a buzzing.

 

Welcome to PriusChat, O fabled King of Kings...

A loud Internal Combustion Engine is not normal, nor is knocking. The ICE is usually very quiet, certainly no louder than a regular Corolla. Did you buy it from a dealer or a private party?

 

not a knock.. but a tick.. you start to think it's knocking.. but it's not. the rx400h has this same noise too... i only hear it when at a drive through window.. or in a tunnel. now that's embarrassing in a Lexus. *shrug*

 

<div class='quotetop'>QUOTE(V8Cobrakid @ Feb 24 2007, 01:38 AM) [snapback]395680[/snapback]</div>

I get a knock not a tick, but only when I first start driving in the morning for the first couple miles when I'm coming to a stop and the gas engine turns off once stopped. It is very noticible, but once the engine has warmed up, the transition from gas to electric isn't that noticable.

 

well my prius and others aswell at work are abit more noisy at idleing when engine is cold compared to many other engines at that size that im used to , maybe alitle more noisy when engine is warmed up aswell. or maybe other cars have better soundprofing in the engine compartment......
im not sure why it sounds a bit more rough ,but i wouldnt be suprised if its because its atkinson engine or ??


Cheers

Andreas

 

Check to make sure that the oil was not overfilled. It's possible for excess oil to get sucked into the combustion air, which is not good.

Note that one or two seconds of run-on or shuddering when the engine shuts itself off is normal (it's burning off remnant fuel to prevent it from evaporating, which would contribute to hydrocarbon pollution). If it really is knocking or pinging, that is *not* normal. Get thee to a dealer for diagnosis.

The engine can roar when accelerating hard or going up a steep hill. That is completely normal; the computers will not let it redline. It is also normal to get sensations similar to those of a slipping clutch; that also is normal because of the design of the Prius transmission.

 

<div class='quotetop'>QUOTE(richard schumacher @ May 16 2007, 11:18 AM) [snapback]443349[/snapback]</div>

Thank you. Still getting used to this new car!

 

I'll reiterate the "dieseling". Sometimes when stopped the Prius will shudder and 'misfire' and try to keep the gas engine from 'dying'. These are all my interpretations. Even after 60,000 miles.

Yes, true, all these are the bane of ICE-only cars (have had a few of these in my driving career, ha, ha), but the Prius is doing it's best to burn un-used fuel, as well as get the engine set for the next take-off. all normal for an un-normal car.

disconcerting if you're used to an older gasser just coughing and gagging trying to remain running at a stoplight. Just the opposite for the Prius, it's trying it's best to kill the engine to provide a cleaner world!

PS It's still fun to have a new passenger unfamilar with the Prius and play dumb at a stop light...oh, damn, the thing died again...the look is priceless.

 

The engine does use solid lifters, not hydraulic, giving much more mechanical noise. It is a small, light, aluminum engine close to the firewall. On my daily walks I hear a lot of cars, and from outside the Prius ICE seems very quiet to me compared to the Corolla or the Accord (new ones.) I have had two cars when at idle sounded like a Prius with ICE off, a 65 Ramber Classic, and an Infiniti Q45. Passengers would say the engine is off all the time. I get the occasional shuddering too. I am not worried about it. I do think oil quality and freshness makes an engine sound quieter. I just changed mine at 1100 miles and definitely the engine is a touch quieter and smoother than on the factory fill. Overall the Prius has a very smooth and quiet drive, and I noticed the miles go fast, almost like the Q45 luxury car feel.

 

I have recently purchased a 100k mile 2004. I am " slightly concerned" about the noise from ICE, especially when cold. Valvetrain?

As posted previously, there are mechanical lifters in ICE. Does anyone here have the sequence and lash specs for the valvetrain?

Thanks
Erik

 

The noisiest thing under my bonnet is the air conditioner compressor. Turn off the auto air and see if it is still noisy. There will be a ticking sound from the injectors if the engine is running.

 

I idled my mothers RX400h next to my prius and my sister's corolla.

From outside the Lexus was the quietest with a 6-cylinder engine, the corolla and prius had the same level of noise.

From inside the Lexus was again the quietest, but its SUV profile is not as aerodynamic as the other cars so expect highway noise to be up.
The inside of the prius is slightly louder than the inside of a corolla, this is due to the fact that the prius has less sound-absorbing material to save weight and increase mpg, this will also result in the prius having the highest tire-noise as well.

I turn off my a/c or defroster when coming to a stop light to ensure the engine shuts off. At normal driving the engine should be barely noticeable, but climbing a mountain or large hill will result in the ICE working very hard and its very loud.

Your prius is off-warranty so you can install the EV mod with no repurcussion, if you are getting engine knocking you may be using cheap 85 or 86 octane gas, use the good stuff, shell increases my mpg +1, and chevron increases my mpg +2.

 

I think it depends a lot on what kind of car you are used to driving. I think the Prius (and maybe entry level toyotas in general) save weight by not using as much noise dampaning material. The prius does make more noise inside than the other cars I am used to driving but they are more "luxury" european cars.