Greetings fine people who know so much more about my car that I do it's ridiculous. I have a Car Talk type question here. . .
Honda Civic EX automatic, 4DR w/ vtec engine here.
When I accelerate and the engine seems to be putting forth more effort than basic acceleration (that point just before the engine races when . . .gosh, I have no idea how to explain this), there is a deep, full hissing (sounds like rattling too, but not exactly) sound that goes on somewhere in my undercarriage. It only occurs at certain points when the engine is putting in a very specific quantity of effort or change in effort, almost as though it's a problem with shifting or something like that. For example, when I have it floored and it's going 115 down the highway, no noise problem (at least, not that noise), but when I'm accelerating from 60-70 or even 20-30, under certain conditions, it makes this noise. It has also done it when I am up around 80 and have taken my foot off of the gas peddle entirely. I've gotten pretty good at predicting when it's going to happen. There is little that seems random about the behavior. It all started one day on a long drive from RI to PA. Nothing specific seemed to precipitate it. It just started to happen. The sensitivity seems to have increased slightly by then, but not too much. Could it be as simple as needing to replace or refill my automatic trans fluid? Thanks for your thoughts.
best regards -- robert

 

Any mods on the car?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by gobengeo &raquo;</TD></TR><TR><TD CLASS="quote">when I have it floored and it's going 115 down the highway</TD></TR></TABLE>

*Sigh*

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by gobengeo &raquo;</TD></TR><TR><TD CLASS="quote"> I have a Car Talk type question here. . .
Honda Civic EX automatic, 4DR w/ vtec engine here.
</TD></TR></TABLE>

You sure the sound your hearing isnt VTEC kicking in?

 

i think its the turbo that you never knew you had...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by anothersickhatch &raquo;</TD></TR><TR><TD CLASS="quote">i think its the turbo that you never knew you had...</TD></TR></TABLE>



Well if it's the undercarriage it has something to do with your suspension. With that said I would check you axles or something in that area. Or **** it could be just air or something. Man reading your post confused me so much as to what the problem could be.

Free Bump!!

 

I say is exhuast leak

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Skynet &raquo;</TD></TR><TR><TD CLASS="quote">I say is exhuast leak</TD></TR></TABLE>
That was my first guess. But usually an exhaust leak is pretty constant ... at least it was when I had one. It wasn't intermittent but rather always there. But I also vote for exhaust leak.

And 115 on the highway? If it's an EJ8, you can't go past 112; the computer relegates top speed to 112 mph.

 

It could be just your intake manifold just whistling at its regular point of harmonic. What are the RPM that the whistling is occuring at? My intake whistles at the point at which the throttle body is open at just the right point as to which the intake manifold whistles...
Just thought I'd offer my input...BTW, mine is a D16Y7

 

then do you have adjustable cam gears?

 

Belts?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Skynet &raquo;</TD></TR><TR><TD CLASS="quote">then do you have adjustable cam gears?</TD></TR></TABLE>
I have no idea what that means. How would I know if it did? What/where would I check?

re: other messages
115 might have been on a slight downhill. 112 on flat seems about right.

There does not seem to be a specific RPM @ which it happens, though I will check more closely on that.

No mods at all(yet)

Definitely not the vtec kicking in. It never happened before and I'd been driving it for almost 2 years and it's definitely a broken something kind of sound.

It really does sound like an air leak of some kind, but I can't imagine where it's coming from or why it comes when it does.

Could an exhaust leak occur at a very specific exhaust output level and not above or below it? Is that somehow a possibility? It's a horrible sound for a car to make. . .it sounds like I don't take care of it. . .well, ok, so I sort of don't. *shrug*

Another note -- when I sit there in neutral or park, I can't get it to do it by revving the engine, no matter how hard I rev it

 

exhaust leak is a good thing : )
less restriction for ur engine : )
possibly pass smog check too: )
jp
jack up the car n look ..... it be easily spotted

 

Get under your hood and rev it up and try to simulate the conditions it happens by opening the throttle manually. You'll hear where the noise is coming from and be able to narrow down what's happening.

 

i had this same problem on my car, but it only happened in 1st and 2nd, it was the air filter sucking in...

 

My old room-mate had an exhaust leak, and it was constant. Added a second tone to his exhaust note at all times, but I guess if other people are saying it's possible then it may be...

Eue to the vagueness of his sound description, maybe it's his intake butterfly? On my engine, and I've heard a lot of other b series do it too so maybe some D's do as well, at a certain throttle point the intake butterfly is at an angle that makes it whistle. Mine does it at ~24 percent throttle (as measured by VAFC).

Does it seem to have anything to do with the gas pedal? In other words, can you make it go away by pushing the pedal down farther or letting off the gas when it starts?

Does your car vibrate at all when this happens, or is it just a noise?

Edit: You know, looking at it again I gotta know... How often do you check your tires, and when was the last time you had the alignment checked?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ShakesTheKlown &raquo;</TD></TR><TR><TD CLASS="quote">Does it seem to have anything to do with the gas pedal? In other words, can you make it go away by pushing the pedal down farther or letting off the gas when it starts?

Does your car vibrate at all when this happens, or is it just a noise?

Edit: You know, looking at it again I gotta know... How often do you check your tires, and when was the last time you had the alignment checked?</TD></TR></TABLE>

I had the alignment checked about 6 months ago. When it's bad, my car vibrates at high speeds, but no hissing sound. The tires look fine too. The car doesn't vibrate at all, as best I can tell, when this happens (though it does when it is idling, which I find to be annoying, but that's another problem -- if someone has a solution to that, let me know -- it has for long as I can remember). Speed does not seem to play much of a roll in the matter either.

To experiment: I was driving up a hill earlier today and I put the gas to the floor. The engine revved, it made the noise for a while, and then something or other engaged, there seemed to be more horse power, and the sound went away. In other words, it seems to happen as the car is building up steam.

Also, the other day, I was messing around with the gears. It seems to happen WAY more in 3rd than in 4th.

Is it possible that there is something wrong in my exhaust system without there being a hole (i.e. something wrong IN the muffler)? Sorry if that's a dumb question. I have no idea how they are composed. Could it somehow be a problem with the automatic trans?

Doing what was suggested in an earlier post, "Get under your hood and rev it up and try to simulate the conditions it happens by opening the throttle manually. You'll hear where the noise is coming from and be able to narrow down what's happening.", be different from revving it in neutral/park? How do I accomplish this task of opening up the throttle manually? I fear I may sound like an idiot for asking this question. Where would I look to find this information?

 

Ok, new news on this hissing thing. It seems only to do it once the engine starts to get towards normal temperature. When I accelerate whilst the engine is still cold, it doesn't do it. This may either indicate that it doesn't have trouble shifting up the gears when it's cooler (i.e. the engine is never racing) or the problem may actually be exaccerbated by the heat? Does any of that make things any clearer?
/robert

 

Definitly that invisible turbo