DIY: Replace Fuel Tank Breather Valve (Fix for bouncing idle at fuel station)

[PACarGuy]

Ended up getting the new hose at my local dealer and installed it a little while ago, buttoned her back up and she's running like a champ! Thanks for all the help.

[RedCardinal]

this and the comments and the reference to that youtube video are great.This part should arrive today and I look forward to doing this tomorrow - I'll report back. For the difficult end of hose, I expect to push in and pinch and then pull out, and if that doesn't work I think I read that I may need to pull up, and if that doesn't work then I'll be using a pick tool to pry it off. And if that doesn't work it appears to be easy to detach the hose at the other hand, and the just take off the entire hose which should make it easier to work with. In fact I should do that right off if it doesn't come away easily. Actually I may detach the other side of the pipe and lift the entire pipe and pump out to make it easier to access. Oh yeah and also occasional bizarre idling bounces. I mean seriously. I almost get all the plastic in the car - weight adds up and if it does the job then why not - but the plastic doesn't always do the job does it. I just changed the coolant and that plastic bleeder screw snapped off on me. I heated up a phillips head screwdriver with a butane lighter, drove it hard into the plastic threaded piece still in there, tapped it with rubber mallet, put ice around it, and when it cooled unscrewed it. whew.

On a side note isnt anyone else irritated about this, I mean I've had to self-diagnose a bad EDC that kept killing the battery, which took years and I bought a few batteries, and an intelligent battery cable, and paid a reputable BMW professional in my area to take a whack at the problem (fail), and god knows what else. And I read this post and was like mind blown, my car has stalled after refueling several times - and also sometimes when I'm refueling at the pump, it stops early as if the car is full, then I drive off and the tank isn't full - now I realize the vacuum thingy here is responsible lmao.

I am sincere when I wonder if this is a lemon. Recently I had a bunch of EDC-related warnings which kicked out errors including a steering wheel angle problem. After taking apart the cover over the battery in the trunk and then disconnecting the battery, I removed the driver's air bag and then took apart the steering wheel and then detached and cleaned the steering angle sensor. This alone didn't fix the problem but weeks later I used BMW tools and my PC to recode the value to 0 and this somehow worked.


Now I'm waiting for the actuators to die.

In a way this car is a perfect DIY project car because so many things have been wrong with it. I bought it new and so this many problems are frustrating. I can't imagine not being a DIY'r and having to deal with this stuff year after year. Also I work from home and this is my driver, if this were my driver and I had to go to work every day I would have dumped it long ago.

Don't get me wrong when everything is running correctly this is, as you all know, a great car. But so many problems, ugh.

[EJT86]

Originally Posted by RedCardinal

this and the comments and the reference to that youtube video are great.This part should arrive today and I look forward to doing this tomorrow - I'll report back. For the difficult end of hose, I expect to push in and pinch and then pull out, and if that doesn't work I think I read that I may need to pull up, and if that doesn't work then I'll be using a pick tool to pry it off. And if that doesn't work it appears to be easy to detach the hose at the other hand, and the just take off the entire hose which should make it easier to work with. In fact I should do that right off if it doesn't come away easily. Actually I may detach the other side of the pipe and lift the entire pipe and pump out to make it easier to access.

On a side note isnt anyone else irritated about this, I mean I've had to self-diagnose a bad EDC that kept killing the battery, which took years and I bought a few batteries, and an intelligent battery cable, and paid a reputable BMW professional in my area to take a whack at the problem (fail), and god knows what else. And I read this post and was like mind blown, my car has stalled after refueling several times - and also sometimes when I'm refueling at the pump, it stops early as if the car is full, then I drive off and the tank isn't full - now I realize the vacuum thingy here is responsible lmao.

I am sincere when I wonder if this is a lemon. Recently I had a bunch of EDC-related warnings which kicked out errors including a steering wheel angle problem. After taking apart the cover over the battery in the trunk and then disconnecting the battery, I removed the driver's air bag and then took apart the steering wheel and then detached and cleaned the steering angle sensor. This alone didn't fix the problem but weeks later I used BMW tools and my PC to recode the value to 0 and this somehow worked.


Now I'm waiting for the actuators to die.

In a way this car is a perfect DIY project car because so many things have been wrong with it. I bought it new and so this many problems are frustrating. I can't imagine not being a DIY'r and having to deal with this stuff year after year. Also I work from home and this is my driver, if this were my driver and I had to go to work every day I would have dumped it long ago.

Don't get me wrong when everything is running correctly this is, as you all know, a great car. But so many problems, ugh.

The issues ur having at the gas station with the pump stopping early is likely due to a flooded vapor canister. The can gets flooded when people top off after the pump has already stopped. It’s pricey but easy to to replace it’s located behind the drivers rear wheel

[JPSurratt2005]

Originally Posted by RedCardinal

Now I'm waiting for the actuators to die.

A BMW tech advised lubricating the shafts that connect all of the throttle body flaps to the actuators. This way you eliminate the chance that the motors and gears wear out due to friction. This is what he recommended.

https://www.amazon.com/08897-Silicon.../dp/B000PJED72

This is what I did at 75k miles and again at 100k miles. So far everything works great and no actuator failure.

[Vuu]

Changed mine out last night since I'm installing my supercharger and decided to do maintenance while everything is off.

Can confirm, I too broke the nipple off lol. After spending too much time trying to pry it out, I decided to cut the hose instead.

[martgsr]

Originally Posted by ThatM3guy

Then, PUSH IN towards the valve, and press the clip, and mine came right off.

I did that with a little wd40 on each clip and goes like a charm.

Originally Posted by ThatM3guy

Getting the plenum to sit in the back was difficult. I asked a Indy shop friend who recommended wiping some silicon lubricant on the surface, and that helped.

I did put some silicon on the rubber ring and the plenum gets in easily.

Thank you for the great write up

[TheTrackDude]

Older thread but for people who have problems with that one push together style connector at the fuel tank breather valve I ended up actually replacing that hose because I mangled the plastic pinch style connector. Also be really careful with the crankcase breather hose connector at the front of the intake plenum. In practice it sits very near the thermostat housing and I think over time it gets brittle.nmine ended up breaking.This is something that I did not have any want replace has the connector in the back is all the way in the back of the motor and very hard to get to. I bandaided mine with some barb style, brass connectors and hose clamps..

[drrust]

It seems that enough people had issues with all of the hoses that ECS has a kit now!

https://www.ecstuning.com/b-assemble...13907838281kt/

[smoothmacdaddy]

hi all, as someone who is absolutely ZERO mechanically inclined, i was able to do this without damaging any clips or cutting any rubber hoses. sharing what i thought was helpful & what i did differently from the OP:

1) you don't need to take off the t-screws by the grill to remove the plenum, i was able to pull the entire airbox + elbow off simply by removing the 2 intake box screws & loosening the elbow hose clamps

2) regarding the rubber hose on the front side of the fuel breather valve: i went ahead and removed this hose first contrary to OP's suggestion. i took a flat head screwdriver and pried back and forth where the hose & FBV meet to loosen it and then shot some WD40 and let it cook for a few minutes. after prying a little more (to try to get the WD40 to penetrate deeper into the hose) it got pretty loose and slipped off with (relative) ease.

3) regarding the rear (most difficult) hose/clip, you want to remove the FBV from the mount by wiggling it off until the rubber grommet comes off. the reason for this is because you can rotate the FBV assembly so that the top & bottom of the clips are exposed so you can actually pinch them down. otherwise, the top clip is blocked by the plug for the other electrical connector you had to remove.

once the FBV is free from the mounting spot, like OP stated, you have to PULL the rear hose/clip INTO/TOWARD the FBV. by pulling it into the FBV first you'll notice the clips have a little more slack & give. don't waste your energy just trying to do 500 reps of taking the clip off but instead, do a snug/strong tug toward the FBV BEFORE pressing the clips and with literally all of the power your fingers have, press on the top and bottom clips and it should pop out

hope this helps, thanks to OP for this ultra detailed guide. helped me tremendously!

[E90325M]

I met twice of my engine just shutdown when I stopped at red light, one of them just happened right after I filled up the gas. So figure out it should be Fuel Tank Breath Valve issue and I am going to order and replace it.
Any suggestion to do more pre maintanance works cause you just have the plenum off and already there?

[DrFerry]

Originally Posted by E90325M

I met twice of my enginee just shutdown when I stopped at red light, this just happend right after I filled up gas, so figure out it should be Fuel Breath value issue and I am going to order it and replace it.
Any suggestion to do more pre maintanance works cause you just have the plenum off and already there?

If not done already perhaps the Throttle Actuators?

[E90325M]

TA done.
Thermal stat done.
Sensor done.

[Johnnyrg]

I replaced my fuel breather valves when I did TA’s

[DrFerry]

I maybe looking at doing mine. I've been getting a "tighten gas cap" notification. I replaced the gas cap and a few days later the message returned. It could be a loose connection or connector at the gas tank breather valve or the valve itself - though the idle after filling up is fine. I just read the codes with the Carly App and no DMTL malfunction code is present only the "loose gas cap" occurrence code shows up. I will monitor and report back.

[kolosy]

Originally Posted by smoothmacdaddy

hi all, as someone who is absolutely ZERO mechanically inclined, i was able to do this without damaging any clips or cutting any rubber hoses. sharing what i thought was helpful & what i did differently from the OP:

1) you don't need to take off the t-screws by the grill to remove the plenum, i was able to pull the entire airbox + elbow off simply by removing the 2 intake box screws & loosening the elbow hose clamps

2) regarding the rubber hose on the front side of the fuel breather valve: i went ahead and removed this hose first contrary to OP's suggestion. i took a flat head screwdriver and pried back and forth where the hose & FBV meet to loosen it and then shot some WD40 and let it cook for a few minutes. after prying a little more (to try to get the WD40 to penetrate deeper into the hose) it got pretty loose and slipped off with (relative) ease.

3) regarding the rear (most difficult) hose/clip, you want to remove the FBV from the mount by wiggling it off until the rubber grommet comes off. the reason for this is because you can rotate the FBV assembly so that the top & bottom of the clips are exposed so you can actually pinch them down. otherwise, the top clip is blocked by the plug for the other electrical connector you had to remove.

once the FBV is free from the mounting spot, like OP stated, you have to PULL the rear hose/clip INTO/TOWARD the FBV. by pulling it into the FBV first you'll notice the clips have a little more slack & give. don't waste your energy just trying to do 500 reps of taking the clip off but instead, do a snug/strong tug toward the FBV BEFORE pressing the clips and with literally all of the power your fingers have, press on the top and bottom clips and it should pop out

hope this helps, thanks to OP for this ultra detailed guide. helped me tremendously!

+1 to all except the rear hose piece. i found it easier to disconnect the other end of it (it's underneath the main fuel line hookup on the strut tower). once it was off, I grabbed a small pair of pliers, wrapped them in electrical tape and _very gingerly_ used them to compress the plastic tabs. could not get them off with my hands even with moving it forward first, but popped right off with the pliers. again -- i only used the pliers to compress the tabs themselves, not to pull or grab the line.

[kninjak]

Need help was trying to remove the hose for the breathe valve and it broke with the plastic still inside,
I tried using a pic to pull out the plastic and the tip broke not sure it flew out or went to the other end where it is connected ,
I cut the hose and tried to look into the metal end but didn’t see anything in there and nothing inside the hose either,
I have hooked up new breather valve , but not sure if should start the car take it to mechanic ,
I am not much mechanically inclined just basic oils change and stuff was trying to learn something new but it came to but in my back
Feel so down
Please help as to what is the metal part that connect to the hose and of that small piece is inside how to fix it,
Thank in advance

[drrust]

Originally Posted by kninjak

Need help was trying to remove the hose for the breathe valve and it broke with the plastic still inside,
I tried using a pic to pull out the plastic and the tip broke not sure it flew out or went to the other end where it is connected ,
I cut the hose and tried to look into the metal end but didn’t see anything in there and nothing inside the hose either,
I have hooked up new breather valve , but not sure if should start the car take it to mechanic ,
I am not much mechanically inclined just basic oils change and stuff was trying to learn something new but it came to but in my back
Feel so down
Please help as to what is the metal part that connect to the hose and of that small piece is inside how to fix it,
Thank in advance

Can you clarify which hose you cut? If cut the plastic nipple and got most of the pieces out as best you could and the connector stayed on it is likely good. If the plenum is still off and you are worried about the hose, one could remove the hose (disconnecting by the strut tower) and confirming it isn’t blocked. I would try to blow air through it. If you cut the connector off and made a “field” connection with a hose and clamps, that would likely work without issue

Don’t be discouraged, many seemingly straight forward jobs are complicated by brittle plastics. For this replacement, I had seen that one of the vendors pairs the hose with the breather valve. If you’re worried about it, replace the hose.

[kninjak]

@drrust
I took out the ICV and all the hoses and tried to look inside all with a pin hole camera didn’t find the broke pic tip,
I am hopping it flew off out and I was not able to see it as it was such a small small tip end of the pic,
I haven’t put back car together as I am waiting for the refurbished valve cover, will put back together by next weekend and see if everything works ok
Thank for your reply

[DrFerry]

I finally got around to replacing my fuel tank breather valve. I removed mine by first disconnecting the end of the black braided pipe that attaches to the black plastic line coming from the fuel tank (located on the driver's side inner fender below the strut tower). I did this so I could remove both the black braided fuel breather hose and the fuel tank breather valve together. Once I had them both on the work bench I pushed the rear braided black hose fitting towards the fuel tank breather valve and then pinched the connector serrated edges with some channel locks. And voila off it came!

I noticed the black plastic tank breather line on my car from the fuel tank wasn't seated in its clip holder on the inner fender. Nor was the black braided breather hose going to the breather valve seated in its clip holder below the throttle actuator shaft.

I took some photos and posted them below with before and after shots. Take a good look inside the black braided breather hose fitting that clips onto the tank breather valve pipe to see the annoying clips which need to be released.

Now I have no more long cranking after filling up with gas. No more "Check Gas Cap" dash warning. No more "Increased Emissions" iDrive warning message, and no more "misfiring on all cylinders" codes being thrown which can cause limp mode. I believe the misfiring on all cylinders was only happening during the long cranking after fill ups with gas. Cost me $40 and worth every penny.

The idle is now much more stable - especially when cold - and rock steady at ~750RPM. Perhaps unmetered air was entering the idle control valve from the fuel tank breather valve being stuck open? Anyways, it's all fixed now.

Black Plastic breather line from the tank:
.

.
Black Plastic breather line not clipped into holder:
.

.
Disconnected braided fuel tank breather valve line:
.

.
Braided fuel tank breather valve line properly clipped into holder below throttle actuator shaft:
.

.
Braided fuel tank breather valve line connection fitting to breather valve end:
.

.
New Bosch Fuel Tank Breather Valve:
.

.
Black plastic breather line properly clipped into holder:
.

.
Finished job. Nestled in its hiding place:
.

.

[M'EM]

Bumping up an old thread to say thanks for the amazing write up. I had the plenum removed for doing some major maintenance and decided to do this replacement too as I had the same symptoms. It was pretty straight forward and honestly I struggled a little more with the front hose than the back connector. I used pliers to pinch the clips on the back connector and pulled really hard and it came right off. All in all took me about 30 mins to remove and replace the valve since I had the plenum removed already. Definitely recommend disconnecting the back connection hose and removing it from the car along with the valve, makes things so much easier.