Failed EVAP Test

[Abazal]

So I went to smog my car on Friday in Elk Grove and my car passed every single test except the evap test.
Does anyone have any experience with this and where I should start first on hunting down where the leak is?

I know I have a strong gas smell in the trunk so could it be possible its in that area?
Any help would be appreciated as its my daily and a father-son project.

Thank you

[Somjuan]

Also worth checking is whether they actually had the fixture to test you at the station. I just dealt with smog a few weeks ago, and they actually didn't have the capability to do it. They just passed me on that portion due to lack of equipment as I understood it. I'm all for fixing a leak, just make sure there really is one.

[Abazal]

What place did you go to get your car smogged?

[epmedia]

Also worth checking is whether they actually had the fixture to test you at the station. I just dealt with smog a few weeks ago, and they actually didn't have the capability to do it. They just passed me on that portion due to lack of equipment as I understood it. I'm all for fixing a leak, just make sure there really is one.

That's the same scenario I had. I don't doubt some stations have the tools now, because they earn more $ when they can 'actually' test it.
---
There are Many hoses that can cause fuel vent test failure, not just the hose from the tank to the charcoal canister. All of the cloth braided hose are leaking, if never been replaced. Hoses on-top of tank(s), hoses to the expansion/over-fill tank, hoses between fuel-pick-up and external fuel pump, and hoses on both ends of the long steel vent tube. The fuel tanks must be lowered to access some of the hoses (large hoses and one small hose).

Here's some pics of when I did a "soapy water squirt bottle" test. I connected regulated air pressure (~2 psi) to the long steel vent tube where it's suppose to connect to the charcoal canister. Be aware the charcoal canister vents to the atmosphere, so the smog tech will have to plug this same end of the steel vent tube to test the fuel vent system - or pinch the hose with ie: vice-grips. Also be aware of possible bad charcoal canister - see important note below.

Click on the images to enlarge...

Regulated air connects down there, next to the radiator.
(that piece of hose on the k-jet pipe is just a protective wrapping, it does not even need to be on there...)
pressurize.jpg

Soapy water making lots of bubbles.
overflow-hoses.jpg

Dissected vent hoses to show the cracks.
bad-hoses.jpg

Inside the charcoal canister - if anybody is curious.
*If it's a rattle-can, some pellets may be lodged inside the steel vent tube, which must be cleaned out so the tank vent system can function.
charcoal-can.jpg

[Mike2002]

Replace the vent hoses from the tanks to the filler neck. I just had to do that on my son's car for the same reason. It is a PITA, but worth it once it is done. Then you do not have to worry about it for another 20 years or so.

While you are in there replace all the fuel lines as well. They are probably leaking or at least cracking (and causing the fuel smell in the trunk).

[320iAman]

I changed my charcoal canister out in 2015 . I got it from FCPEuro it was $100 plus change-BMW one, they are now $160.00, glad they have lifetime warranty.

16121108926-1.jpg

Changing Ventilation Hoses is a breeze, from an earlier post. 03-29-2017, 12:18 PM

Finished up on gas tank ventilation and installed -hose and clamp replacement-back end of system,New Activated Carbon Filter canister installed earlier in the front end of the gas tank ventilation system, did not do Left and Right gas tank Top Hose, later for that one. This is what it looks like when pulled thru the tunnel from the Y connector seen thru the access plate removal to left gas tank under the rear bench seat to the trunk. Dont need fish tape or small small jet line reel to get hose thru the pipe-tunnel with a leader, newer stiffer hose does that for ya all and me 3. This system is powered by vacuum created by the motor--intake stroke more precisely, Note the small hose on top of the evaporation tank connects to the hard plastic hard line connecting to 1470 mm metal line which runs underneath the BMW E21 on the passenger side and then comes across the front of the engine bay-Nose section of the car- by the bottom of the radiator to the Charcoal Canister via another hose connected, the hidden line no one pays attention too, well almost..

DSCI0063.jpgDSCI0064.jpgDSCI0065.jpgDSCI0066.jpg

Randy

[Somjuan]

Sent you a text with the place, plan for a couple hours

[320iAman]

That's the same scenario I had. I don't doubt some stations have the tools now, because they earn more $ when they can 'actually' test it.
---
There are Many hoses that can cause fuel vent test failure, not just the hose from the tank to the charcoal canister. All of the cloth braided hose are leaking, if never been replaced. Hoses on-top of tank(s), hoses to the expansion/over-fill tank, hoses between fuel-pick-up and external fuel pump, and hoses on both ends of the long steel vent tube. The fuel tanks must be lowered to access some of the hoses (large hoses and one small hose).

Here's some pics of when I did a "soapy water squirt bottle" test. I connected regulated air pressure (~2 psi) to the long steel vent tube where it's suppose to connect to the charcoal canister. Be aware the charcoal canister vents to the atmosphere, so the smog tech will have to plug this same end of the steel vent tube to test the fuel vent system - or pinch the hose with ie: vice-grips. Also be aware of possible bad charcoal canister - see important note below.

Click on the images to enlarge...

Regulated air connects down there, next to the radiator.
(that piece of hose on the k-jet pipe is just a protective wrapping, it does not even need to be on there...)
pressurize.jpg

Soapy water making lots of bubbles.
overflow-hoses.jpg

Dissected vent hoses to show the cracks.
bad-hoses.jpg

Inside the charcoal canister - if anybody is curious.
*If it's a rattle-can, some pellets may be lodged inside the steel vent tube, which must be cleaned out so the tank vent system can function.
charcoal-can.jpg

Robert you like making bubbles ?

Randy

[epmedia]

Robert you like making bubbles ?

Randy

Actually yes, making bubbles is always fun

[Abazal]

would you happen to have the measurements of the hoses? I was trying to find them on realoem but the page would not load for me.

I changed my charcoal canister out in 2015 . I got it from FCPEuro it was $100 plus change-BMW one, they are now $160.00, glad they have lifetime warranty.

16121108926-1.jpg

Changing Ventilation Hoses is a breeze, from an earlier post. 03-29-2017, 12:18 PM

Finished up on gas tank ventilation and installed -hose and clamp replacement-back end of system,New Activated Carbon Filter canister installed earlier in the front end of the gas tank ventilation system, did not do Left and Right gas tank Top Hose, later for that one. This is what it looks like when pulled thru the tunnel from the Y connector seen thru the access plate removal to left gas tank under the rear bench seat to the trunk. Dont need fish tape or small small jet line reel to get hose thru the pipe-tunnel with a leader, newer stiffer hose does that for ya all and me 3. This system is powered by vacuum created by the motor--intake stroke more precisely, Note the small hose on top of the evaporation tank connects to the hard plastic hard line connecting to 1470 mm metal line which runs underneath the BMW E21 on the passenger side and then comes across the front of the engine bay-Nose section of the car- by the bottom of the radiator to the Charcoal Canister via another hose connected, the hidden line no one pays attention too, well almost..

DSCI0063.jpgDSCI0064.jpgDSCI0065.jpgDSCI0066.jpg

Randy

[320iAman]

would you happen to have the measurements of the hoses? I was trying to find them on realoem but the page would not load for me.

No, I took the measurements and wrote on them paper and then discarded,, I did use Nylon and Stainless Steel Braided Fuel Hose though, I Think AN8 and AN6 1/2" and 3/8"--double check yours.

Actually yes, making bubbles is always fun

lol

Randy