Engine knocking- normal, or something wrong?

[jetfuel]

...can somebody explain the "purge valve"..
...hey Pete..what is "frequency valve" and how do they work...
...I'm lost with this tiny engines.....

jetfuel

[Westfield 11]

Originally Posted by rawlus®

i could counter that it may be brand new, but it is not a slick little car. it is an anomoly - 3 cyl engines run and sound differently from more-balanced 4, 6 and 8 cyl engines. i'm pretty convinced the rattle and unevenness of idle is a characteristic of the engine design itself and not something that needs *fixing* nor can it be fixed. it's like a 3-cyl tractor on the farm. it's a little rough around the edges, especially at low rpms. unbalanced, shaky, strange, unfamiliar.

Doesn't a 3-cyl engine with a 120 degree crank have perfect primary balance? I know my 3-cyl Laverda RGS is smooth at all rpm's the same with the 3-cyl BMW's I have ridden. Shakes and vibrations are not inherent to this configuration. Offset crankpins can achieve perfect primary balance in any configuration. A 3-cyl with a 180 degree crank like the Laverda Jota will be a shaker indeed, since 2 pistons are going up while only 1 is going down. Typically the odd piston is the center one to give better secondary balance. But I don't think that's the case here.

[jimvw57]

I have heard the same noise on a Geo Metro which has pretty much the same motor. Turn up the radio.

[a2jack]

Pete. That's good news on the 100k warranty as long as the P valve is really the noise problem.

I question it only because none of our members on this board have posted that they have personally run this down. Every one so far just repeats the hear-say.

Just where is the purge valve located on the engine?

Can an owner get to it and verify the sound is coming from that point?

Our car goes in tomorrow for the 20k service I will gather what information I can, but in the past the dealer has insisted the "Tapping" is normal.

I'll report back. A2Jack

[Westfield 11]

Originally Posted by jimvw57

I have heard the same noise on a Geo Metro which has pretty much the same motor. Turn up the radio.

They have the same motor only in the sense that a Ford, Chevy, and Dodge have the same motor: they all have 8 cylinders.......

Might I suggest earplugs rather than drowning out the noise in loud music. Hearing loss caused by longterm exposure to excessive sound pressure is no joke. Fact is, the damage you do in your 20's is the hearing loss you suffer in your 50's. This is well proven and not open to debate.

I do however assume you plan to live until that age, if not then crank it up and Rock Out!!! Just don't make the mistake of living too long, unless you like the idea of spending the last 30 to 40 years with hearing aids. Is it true that the ladies love a guy with plastic tubes in his ears?

[theguywiththelongestname]

Originally Posted by UNTODDLY

IT'S NORMAL!!! I have driven several of them, i've put 5k miles on mine, and they all have the same noise, Mostly at idle. It really doesn't matter "what" is making the noise. They all sound like a sewing machine!

yes..."sewing machine" does describe the sound quite accurately...

[BE.SMART]

I have heard the same noise. It is pretty irritating.

To make it worse......I went into R out of my driveway and I sware the damn car backfired on me. It was pretty hilarious. I looked down my street and one of my neighbors was out just looking at me almost startled. I wonder how loud it was???

Anyone backfire yet?

Eric

[jimvw57]

Originally Posted by Westfield 11

They have the same motor only in the sense that a Ford, Chevy, and Dodge have the same motor: they all have 8 cylinders.......

Might I suggest earplugs rather than drowning out the noise in loud music. Hearing loss caused by longterm exposure to excessive sound pressure is no joke. Fact is, the damage you do in your 20's is the hearing loss you suffer in your 50's. This is well proven and not open to debate.

I do however assume you plan to live until that age, if not then crank it up and Rock Out!!! Just don't make the mistake of living too long, unless you like the idea of spending the last 30 to 40 years with hearing aids. Is it true that the ladies love a guy with plastic tubes in his ears?

If I haven't done any damage by now, I won't worry too much about it. Been hittin that Rock n Roll music since the mid '60's. If the Grateful Dead's wall of sound couldn't do it, I doubt the little radio in a Smart can...

[Old smart]

There is a normal constant noise, but I don't know as I would call it "tapping," and it may be a different thing than reported. It is the electric fuel pump in the fuel tank cycling. It is quite evident when the gas cap is off and the engine is running. Not "tap-tap-tap," but a low "tunk-tunk-tunk."

[NuBiker]

I'd swear mine is more of a tap-tap-tap. From these posts I am guessing it's normal. I use premium gas in the car. It seems to go away at a faster idle, that's what bugs me.
It's a great car otherwise.