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When performing a evap smoke test, should smoke come out by the top of the gas tank

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  • Kirk Roland
    Kirk Roland Dec 31, 2016

    Thx for the answer

  • Kirk Roland
    Kirk Roland Dec 31, 2016

    I 2001 dodge ram 1500 5.9L

  • Kirk Roland
    Kirk Roland Dec 31, 2016

    I had hooked up the smoke machine to the line by the evap test port. I didn't have the Schrader valve for the hook up this way.I saw smoke coming out of the top of the tank, but can't see it. Tryed with a mirror but started to get dark and rain so I went in for the night

  • Kirk Roland
    Kirk Roland Dec 31, 2016

    Is there a way to upload photos to you?

  • old marine
    old marine Jan 01, 2017

    I'm pretty sure that for your model, all the evaporative emissions purge valves, vent valves, leak detection pump, etc. are under the hood. The charcoal canister is next to or in front of the fuel tank, and the only items that would be leaking smoke from the top of the tank are the filler tube and vent tube (you would see smoke from these if you took off the gas cap) and the rollover valve(s). There should be a small vacuum line from the charcoal canister to the rollover valves - check that this line is in good condition and attached securely at both ends.

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  • Cars & Trucks Master
  • 1,986 Answers

When you're doing a smoke test, any smoke that shows reveals the problem area if you are doing the test properly. If the smoke is showing near the top of the gas tank, you have a leak in the tubing or the vent valve is not closing (if it's in that area - you didn't provide make, year, model).

Posted on Dec 31, 2016

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SOURCE: Engine light comes on 2003 Jeep grand cherokee laredo

Check the Fuel Pump Relay, it may be malfunctioning and need replaced. Also, in some vechicles, if the batter is disconnected and reconnected, the service engine light will come on from time to time, going off and on simultaneously. Have a diagnostics done to see if any codes show up. If no codes appear, then have them all cleared and drive for another 200 miles. Sometimes the computer will need to be cleared a couple times before the light will stay off. Make sure that all fuses and relays are good, and securey in place. Check all factory installed lights to make sure they are good, and securly in place as well.

Posted on Mar 31, 2009

  • 236 Answers

SOURCE: 03 Jeep Liberty - Evap system small leak

how about the filler neck. just had to replace mine and now its fine

Posted on Jun 18, 2009

  • 5 Answers

SOURCE: 1991 jeep wrangler won't pass evap test,i replaced

make sure you get a cap from the dealer. I had similar issue.... bought cap from autozone...still threw the code....thought must be something else.

ended up replacing all the vacuum lines ... still threw a code

desperate, bought new cap from dealer.... problem solved!

Posted on Aug 25, 2009

  • 1 Answer

SOURCE: 2003 dodge caravan gas cap message comes on dash

Not repaired, fleet vehicle for a friend, looking for some food for thought

Posted on Jan 16, 2010

jturcotte
  • 8273 Answers

SOURCE: check engine light -- daewoo disgnostic trouble

This is a leak in the evap system that monitors and controls the pressure in the fuel tank. Make sure your gas cap is tight. There may be a cracked hose. There is a long line that goes from the gas tank to the evap cannister, which is usually in the engine compartment. Check the rubber hoses that connect this line to the gas tank and to the evap cannister. Also check the other hose that goes from the evap cannister to the engine intake manifold. If the hoses seem old and stiff, replace them--the cost of hose is small. Let us know if you need more help or have more questions.

Posted on Sep 14, 2010

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1 Answer

What is a smoke test?


A test for the leak. A machine blows smoke into the evap system (the charcoal canister trap for gas vapors and the tubing associated with the evap system-including a line from the gas tank to the canister) . A small leak is hard to find, so a smoke test will help.

Nov 20, 2016 | Dodge Cars & Trucks

1 Answer

Where is my evap located on a 1998 pontiac grand prix


which part of the evap system are you looking for. there are several components in your evap system. if you are looking for the evap canister it is located near the rear of the vehicle either on drivers side near the gas tank or just in front of the gas tank. it is a black plastic box with usually 2 vacuum lines running into it. if you are going off an evap leak engine code start with a new gas cap. a bad seal on a gas cap can cause the computer to read an evap leak. if that doesnt work then you may need to have a smoke test done at a local garage. basically they fill the evap system with smoke with a special machine then look for the smoke to appear from the leak in the system. again the evap system consists of several components that run from the engine to the gas tank. it circulates the vapor fumes from the gas back to the tank to be reburned so it does not get released into the atmosphere.

Sep 21, 2013 | Cars & Trucks

1 Answer

Check engine light/evap leak


Getting a smoke test is the right direction to go in.
The computer vents the gas tank to the vapor canister while the engine is running. It also pressure tests the system for leaks. Some where between the gas tank and the vapor canister there may be a leaking hose or valve. Or it could be the gasket on top of the tank where the pump assembly went in.
The gas cap could have been a source for the leak, the other things are not involved.

Apr 24, 2013 | Oldsmobile Cars & Trucks

1 Answer

Engine light has been on, changed gas cap and it went off for 2 days. went to auto parts store and they put the little gauge on it and it read that i have a small evap leak. Need to know what else it could...


The problem may be something that needs a shop to fix.
The computer vents the fumes from the gas tank to the vapor canister several times while the engine is running.
Any part of the EVAP system can leak, including the vent valve on top of the gas tank.
A shop would do a visual inspection then a smoke test where they induce smoke into the tank and check for leaks.

Feb 21, 2013 | Chrysler Sebring Cars & Trucks

1 Answer

PO456 trableshooting


Info found at: http://www.obd-codes.com/p0456

Maybe try cleaning, tightening, or replacing the gas cap first?


P0456 Article by Dale Toalston ASE Certified Technician

Evaporative Emissions System - Small leak detected

The Powertrain Control Module (PCM) at different times performs various tests on the EVAP system. OBD II Enhanced EVAP systems are in place to keep fuel tank vapors from venting into the atmosphere, and instead purges them into the engine to be burned. Regular pressure tests are conducted by the PCM to monitor the sealed system for leaks. The PCM monitors the EVAP system pressure by watching the fuel tank pressure (FTP) sensor. When the sensor indicates a small leak in the EVAP system, this code is set.

Potential Symptoms:

There will likely be no noticeable symptoms other than the Malfunction Indicator Lamp (MIL). This is because the EVAP system is a closed system and only controls fuel tank vapors, not engine management.

Causes:

Usually this P0456 code is caused by an incorrect or faulty gas cap. Filling the fuel tank with the engine running could conceivable cause this code as well or if the cap wasn't properly tightened. Any of the following could also be the cause:

- A small leak in any of the EVAP hoses or fuel tank hoses

- A small leak in the purge valve or vent valve

- The EVAP Canister may be leaking

Possible Solutions:

First, using a scan tool activate the vent solenoid, sealing the system. Then monitor the fuel tank pressure (FTP) sensor. If the system is sealing properly, the number will stay consistent. If is isn't, the pressure sensor will show that as well. If the system slowly leaks, use a smoke machine and watch for smoke exiting the system at any EVAP component. Any where there is smoke exiting the system, that is the faulty component. Do not pressurize the EVAP system with air pressure. Doing so can damage the purge and vent solenoids in the system.

Apr 13, 2011 | 2004 Volvo XC70

1 Answer

Evap code p0456


P0456 - Evaporative Emissions System - Small leak detected
The Powertrain Control Module (PCM) at different times performs various tests on the EVAP system. OBD II Enhanced EVAP systems are in place to keep fuel tank vapors from venting into the atmosphere, and instead purges them into the engine to be burned. Regular pressure tests are conducted by the PCM to monitor the sealed system for leaks. The PCM monitors the EVAP system pressure by watching the fuel tank pressure (FTP) sensor. When the sensor indicates a small leak in the EVAP system, this code is set.
Potential Symptoms

There will likely be no noticeable symptoms other than the Malfunction Indicator Lamp (MIL). This is because the EVAP system is a closed system and only controls fuel tank vapors, not engine management.

Causes: Usually this P0456 code is caused by an incorrect or faulty gas cap. Filling the fuel tank with the engine running could conceivable cause this code as well or if the cap wasn't properly tightened. Any of the following could also be the cause:
* A small leak in any of the EVAP hoses or fuel tank hoses
* A small leak in the purge valve or vent valve
* The EVAP Canister may be leaking

Possible Solutions: First, using a scan tool activate the vent solenoid, sealing the system. Then monitor the fuel tank pressure (FTP) sensor. If the system is sealing properly, the number will stay consistent. If is isn't, the pressure sensor will show that as well. If the system slowly leaks, use a smoke machine and watch for smoke exiting the system at any EVAP component. Any where there is smoke exiting the system, that is the faulty component. Do not pressurize the EVAP system with air pressure. Doing so can damage the purge and vent solenoids in the system.


Hope this helps.

Mar 24, 2011 | 2007 Mitsubishi Endeavor

2 Answers

Check engine light -- daewoo disgnostic trouble code p0442..what is it and is a major/minor problem --performed visual inspec. on fuel cap, evap hoses and canister..all ok..no sign of leak noticed when...


Okay no leaks so this means the vent valve is closing, how did you get valve to close? if there are no leaks and vent valve is closing and sealed when you smoke tested it then i would say to replace the purge valve, this is easy to change and not costly, just a dealer part or maybe you can find on the web, hope this helps.

Sep 14, 2010 | 1999 Daewoo Leganza

1 Answer

Dodge neon code p0456


What does that mean? The Powertrain Control Module (PCM) at different times performs various tests on the EVAP system. OBD II Enhanced EVAP systems are in place to keep fuel tank vapors from venting into the atmosphere, and instead purges them into the engine to be burned. Regular pressure tests are conducted by the PCM to monitor the sealed system for leaks. The PCM monitors the EVAP system pressure by watching the fuel tank pressure (FTP) sensor. When the sensor indicates a small leak in the EVAP system, this code is set.
FB.init("dd7d9e9681341cde77587bc6a2029f6f"); OBD-Codes.com on Facebook Potential Symptoms There will likely be no noticeable symptoms other than the Malfunction Indicator Lamp (MIL). This is because the EVAP system is a closed system and only controls fuel tank vapors, not engine management.
Causes Usually this P0456 code is caused by an incorrect or faulty gas cap. Filling the fuel tank2_bing.gif with the engine running could conceivable cause this code as well or if the cap wasn't properly tightened. Any of the following could also be the cause:
  • A small leak in any of the EVAP hoses or fuel2_bing.gif tank hoses
  • A small leak in the purge valve or vent valve
  • The EVAP Canister may be leaking
Possible Solutions First, using a scan tool activate the vent solenoid, sealing the system. Then monitor the fuel tank pressure (FTP) sensor. If the system is sealing properly, the number will stay consistent. If is isn't, the pressure sensor will show that as well. If the system slowly leaks, use a smoke machine and watch for smoke exiting the system at any EVAP component. Any where there is smoke exiting the system, that is the faulty component. Do not pressurize the EVAP system with air pressure. Doing so can damage the purge and vent solenoids in the system.

May 25, 2010 | 2004 Dodge Neon

1 Answer

The engine light is on in my 2001 Chrysler Concorde. Pulled the code: P0456 came up. Any ideas?


Evaporative Emissions System - Small leak detected

The Powertrain Control Module
(PCM) at different times performs various tests on the EVAP system. OBD II Enhanced EVAP systems are in place to keep fuel tank
vapors from venting into the atmosphere, and instead purges them into the engine to be burned. Regular pressure tests are conducted by the PCM to monitor the sealed system for leaks. The PCM monitors the EVAP system pressure by watching the Fuel tank pressure sensor (FTP). When the sensor indicates a small leak in the EVAP system, this code is set.

Usually this P0456 code is caused by an incorrect or faulty gas cap. Filling the fuel tank with the engine running could conceivable cause this code as well or if the cap wasn't properly tightened. Any of the following could also be the cause:
· A small leak in any of the EVAP hoses or fuel tank hoses
· A small leak in the purge valve or vent valve
· The EVAP Canister may be leaking

Possible Solutions
First, using a scan tool activate the vent solenoid, sealing the system. Then monitor the fuel tank pressure (FTP) sensor. If the system is sealing properly, the number will stay consistent. If is isn't, the pressure sensor will show that as well. If the system slowly leaks, use a smoke machine and watch for smoke exiting the system at any EVAP component. Any where there is smoke exiting the system, that is the faulty component. Do not pressurize the EVAP system with air pressure. Doing so can damage the purge and vent solenoids in the system.

Nov 22, 2009 | 2001 Chrysler Concorde

3 Answers

2000 cavalier check engine light code po440


P0440 - Evaporative Emission (EVAP) System


evaporative emission (EVAP) system has a large leak.
Check the gas cap or vent valve. these are the most common problems.


The Powertrain Control Module (PCM) at different times performs various tests on the EVAP system. OBD II Enhanced EVAP systems are in place to keep fuel tank vapors from venting into the atmosphere, and instead purges them into the engine to be burned. Regular pressure tests are conducted by the PCM to monitor the sealed system for leaks. The PCM monitors the EVAP system pressure by watching the Fuel tank pressure sensor (FTP). When the sensor indicates a small leak in the EVAP system, this code is set.


Here are some additional causes.

* A small leak in any of the EVAP hoses or fuel tank hoses
* A small leak in the purge valve or vent valve
* The EVAP Canister may be leaking

Jun 06, 2009 | 2003 Chevrolet Cavalier

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