Help me find the hissing noise

[ThunderbirdJunkie]

It's just a vacuum line, the same one Vtolds posted a picture of.

 

[Vtolds]

for my reference what were the issues that having a broken vacuum line like that cause?

 

[ThunderbirdJunkie]

Noise, frustration, and dirt getting sucked into the engine.

 

[Vtolds]

So what is the purpose of the line if all the problems associated with it being broken consist of be annoying and sucking dirt into the motor?

 

[ThunderbirdJunkie]

You're right.
Just leave the hose off. Ya don't need it

 

[Vtolds]

You're right.
Just leave the hose off. Ya don't need it

Something tells me that you either dont know what the hose actually does, or your just trying to be a *****...either way why answer if you dont have a good answer?headscratch.gif

 

[ptsb5a]

Hey Vtolds, TBJ knows exactly what it does. He's prodding you to find your own. You should do a wee bit of research or reading into EVAP systems and what they do. I'm absolutely certain you can find all the answers you need by being a bit proactive. Take it upon yourself to cure your curiosity..

 

[ptsb5a]

EVAPORATIVE EMISSIONS
DESCRIPTION - EVAPORATION CONTROL
SYSTEM
The evaporation control system prevents the emission
of fuel tank vapors into the atmosphere. When
fuel evaporates in the fuel tank, the vapors pass
through the control valve located in the top section of
the fuel pump module, through the fuel management
valve, and through vent hoses and tubes to a charcoal
filled evaporative canister. The canister temporarily
holds the vapors. The Powertrain Control
Module (PCM) allows intake manifold vacuum to
draw vapors into the combustion chambers during
certain operating conditions.
Gas powered engines use a duty cycle purge system.
The PCM controls vapor flow by operating the
duty cycle EVAP purge solenoid. Refer to Duty Cycle
EVAP Canister Purge Solenoid.
When equipped with certain emissions packages, a
Leak Detection Pump (LDP) will be used as part of
the evaporative system for OBD II requirements.
Also refer to Leak Detection Pump.
Vehicles powered with gasoline engines are also
equipped with ORVR (On-Board Refueling Vapor
Recovery). Refer to ORVR for additional information.

NOTE: The evaporative system uses specially manufactured
lines/hoses. If replacement becomes necessary,
only use fuel resistant, low permeation
hose.

EVAP/PURGE SOLENOID
DESCRIPTION
The duty cycle EVAP canister purge solenoid (DCP)
is located in the engine compartment. It is attached
to a bracket located between the battery and the
Power Distribution Center (PDC). The EVAP system
test port is located near the solenoid.
OPERATION
The duty cycle EVAP canister purge solenoid (DCP)
regulates the rate of vapor flow from the EVAP canister
to the intake manifold. The Powertrain Control
Module (PCM) operates the solenoid.
During the cold start warm-up period and the hot
start time delay, the PCM does not energize the solenoid.
When de-energized, no vapors are purged. The
PCM de-energizes the solenoid during open loop operation.
The engine enters closed loop operation after it
reaches a specified temperature and the time delay
ends. During closed loop operation, the PCM cycles
(energizes and de-energizes) the solenoid 5 or 10
times per second, depending upon operating conditions.
The PCM varies the vapor flow rate by changing
solenoid pulse width. Pulse width is the amount
of time that the solenoid is energized. The PCM
adjusts solenoid pulse width based on engine operating
condition.

 

[Ry' N Jen]

I can see doing an emergency trail side repair with electrical or duct tape...
But to call it fixed now?

M-I-C-K-E-Y- M-O-U-S-E !

For your own piece of mind, replace the vacuum hose with new material.
And no reason to be disrespectful to Eric.

 

[AJK381]

yea i usto work at a jeep dealer we had a buncha kjs come in with that prob, half the time the owner didnt even notice and we just threw a new piece of 3/8 hose on it.

 

[RChris173]

Found it. Quick fix, I used electric tape. nana.gif I dont know if that is a good way to fix it, but its working.

I have this same exact problem. The connector is cracked and the hoses are hissing.

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I put electrical tape on it as a temp fix until I can get it fixed properly. For now, the hissing is gone.

Does anyone know what the proper part is to replace with? Is this something generic enough or do I need to get an OEM dealer part?

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Thanks,

Chris

 

[LibertyTC]

EVAP or Vacuum leaks generally will cause the KJ to run like :favorites68:
Electrical tape will not hold that long under the kJ, so get some new hose.
Checking for leaks....or....I like Ryan's Stethoscope!
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[RChris173]

EVAP or Vacuum leaks generally will cause the KJ to run like :favorites68:
Electrical tape will not hold that long under the kJ, so get some new hose.
Checking for leaks....or....I like Ryan's Stethoscope!

I have noticed that the fuel economy is a lot less than it used to be, not sure if that is related though.

What kind of things can this hose leak affect?

Where should I get the replacement hose?

Since I found this problem, is there a methodology to finding other leaks for maintenance?

 

[LibertyTC]

CEL light should be on. Example (small leak/ EVAP detected)
Will effect idle,fuel mileage,driveability possible unburnt gas odors.
Replacement hose from dealer or can use vacuum hose available at parts store 3/8"?
The best way to check for leaks is with dealer or Shop's smoke machine.
Otherwise Like previously mentioned/shown, the auto stethoscope can assist in hearing a vacuum air leak as well.

 

[RChris173]

CEL light should be on. Example (small leak/ EVAP detected)
Will effect idle,fuel mileage,driveability possible unburnt gas odors.
Replacement hose from dealer or can use vacuum hose available at parts store 3/8"?

I did not have any indicator lights illuminated, even though I have an issue with this hose...

 

[ThunderbirdJunkie]

It won't always turn the CEL on. It didn't on ThunderbirdJunkie's.

 

[RChris173]

It won't always turn the CEL on. It didn't on ThunderbirdJunkie's.

True... just like if the fuel fill cap is not on, sometimes the light may come on because of loss of vaccum/pressure?

 

[ThunderbirdJunkie]

correct...but it doesn't always come on.

 

[journeyjim]

Beings it's a gas vapor hose, shouldn't a gas compatible hose be used instead of a regular vacuum hose?. I also agree on changing the hose to a new one, but if your going to use tape, use gorilla glue tape, it'll stick to anything.

 

[auburn4193]

I have a really loud hissing noise on my '03 KJ.. it's louder than the engine itself when it's running. The noise on mine sounds like it's coming from the passenger side. I have the 2.4 4 ******.