stevew84

when my b18c1 is idling i hear a hissing sound, almost sounds like an air leak. im not sure if it is sucking in or blowing out or where it is coming from. could this car my car to idle rough/low? it doesnt idle high or even normal...only about 200rpm. i've posted other threads regarding this but the hissing noise just came to mind.

please help!!

steve

Blk00EJ8

your car won't idle at 200 rpm. if you're looking at your dash tach then it's not accurate. if it was a vacuum leak then your idle would be adversely affected.

where does it sound like it's coming from? maybe it's just your intake filter?

b18crx88

mine hiss' also it comes from the intake and if you listen close enough and when you get out of the throttle it makes a pshh sound like im running 2lbs of boost SICK

ho bag

Sounds like a vacuum leak. This will cause a change in idle as well.

Start on one side and move to the other checking all hoses.

stevew84

it is coming from the intake manifold side of the engine. its VERY loud thats why i dont think its the filter. i have a cold air intake on my ef and it hisses...when i rev it. but not when its just sitting. this sounds like when u let air out of a balloon, loud hissing.

as far as my tach...its the oem tach in dash no aftermarket. it does work because once the car warms up the needle settles around 500rpm. and reacts accordingly to the accelerator. i have to constantly have my foot on the gas for it to stay running, at lease first time i fire it up.

stevew84

this is why i dont like buying cars, always unmentioned problems and when u ask the person about it after the fact the response is the same..."thats wierd, that never happened to me."

a little off topic...has anyone ever used the "stop leak" series of fluids? power steering, oil, tranny, and even a head gasket fixer one like $20 per quart!!.

on my ef and my ek i have little dripps coming from the distributor side of the engine same color same consistancy like a gold color its NOT oil for the ef but for the ek i think my distributor O ring is blown, the one on my ef needed replacing now im leaking tranny fluid from that. for the ek i had to replace oil filter due to rippied gasket AND a second oil filter gasket stuck to block!! the idiot i bought this from didnt check his filter right i guess. but not i have small drips only after i run it a couple miles and its nice and hot.

NoBrows

seems like a vacum leak to best way to find it take carb clearner and spray it on the intake manifold and when the idle changes thats were your leak is

Blk00EJ8

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by stevew84 &raquo;</TD></TR><TR><TD CLASS="quote">as far as my tach...its the oem tach in dash no aftermarket. it does work because once the car warms up the needle settles around 500rpm. and reacts accordingly to the accelerator.</TD></TR></TABLE>

Never said it didn't work... I said inaccurate. The motor will not run any lower than about 400 rpm, no matter what the tach says, and even then will be ready to choke. That's why digital tachs are now used, because analog tachs are often off. Mine is off by about 3-400 rpm in the midrange.

Nonetheless, everyone keeps saying vacuum leak. ATTENTION: A vacuum leak will not cause a LOW idle! If the OP could narrow down better where it's coming from then that may help.

NoBrows

[
Nonetheless, everyone keeps saying vacuum leak. ATTENTION: A vacuum leak will not cause a LOW idle! If the OP could narrow down better where it's coming from then that may help.[/QUOTE]

WELL ACTUALLY a small leak could cause a low idle because the computer could detected a lean a condition then add more fuel then nessary then it would bog the engine down causing a low idle

egb18c5

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by NoBrows &raquo;</TD></TR><TR><TD CLASS="quote">seems like a vacum leak to best way to find it take carb clearner and spray it on the intake manifold and when the idle changes thats were your leak is</TD></TR></TABLE>

i have to try that one myself

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by NoBrows &raquo;</TD></TR><TR><TD CLASS="quote">WELL ACTUALLY a small leak could cause a low idle because the computer could detected a lean a condition then add more fuel then nessary then it would bog the engine down causing a low idle </TD></TR></TABLE>

x2

Blk00EJ8

That's what your idle air control valve is for. Exactly the counterpart of what you said, if the ECU detects that the engines running too rich or too low, guess what, more air. Small vac leak will idle higher than normal. Large vacuum leak will cause a high, hunting idle because the ECU is in a constant state of trying to return to a steady state idle.

In example, your throttle body's idle adjustment screw is a controlled vacuum leak. Open it more and your idle is slightly higher.

mas2alias

i kno for a fact its a vacume leak....
try to find it
look up a diagram of ur IM

if u cant find it then adjust the idle screw to raise the idle

BryanM.

iTrader: (1)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Blk00EJ8 &raquo;</TD></TR><TR><TD CLASS="quote">Nonetheless, everyone keeps saying vacuum leak. <FONT COLOR="red">ATTENTION: A vacuum leak will not cause a LOW idle! </FONT>If the OP could narrow down better where it's coming from then that may help.</TD></TR></TABLE>

blk92_d16

Sounds exactly what I've got on my Z6 hatch. It's my IACV. It only levels off @ operating temp.

ArchEnemy

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Blk00EJ8 &raquo;</TD></TR><TR><TD CLASS="quote">


Nonetheless, everyone keeps saying vacuum leak. ATTENTION: A vacuum leak will not cause a LOW idle! If the OP could narrow down better where it's coming from then that may help.</TD></TR></TABLE>

Wait it wont? what do you mean? Oh... EFI? what that? i thought that big aluminum thing was a carburetor?

Blk00EJ8

It turns out that posters to this thread are either with my opinion or completely against it, lol.

Someone do me a favor and unplug the hose for your cruise control if you have it. Then cover it up with your finger and start to slide your finger off so the vac leak is tiny. What happens?

King V

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Blk00EJ8 &raquo;</TD></TR><TR><TD CLASS="quote"> Large vacuum leak will cause a high, hunting idle because the ECU is in a constant state of trying to return to a steady state idle.
</TD></TR></TABLE>

I agree . I disconnected a vac line unknowingly off the back of the manifold once when doing an oil change and the idle would hunt from 1-2000 rpm up and down. Really frigging annoying. And I got a P0171 system lean DTC. Unmetered air is a bitch.

egmatt93

this might sound weird but make sure ur dipstick is in, or all the way in. learned from exp that it make almost the same sound ur hearing when u forget to put it in or click it into place

Username 51

King V

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Username 51 &raquo;</TD></TR><TR><TD CLASS="quote"> </TD></TR></TABLE>

WTF! That's a hissing sound!!!!

BryanM.

iTrader: (1)

Damn, that's crazy, what a mess. Snake burger anyone?