Cracked fuel tank / filler neck argh!

E

ErikR

Veteran Member
Joined
Feb 14, 2006
Location
Long Island NY
TDI
06 Jetta TDI pk2 5-spd Black/Black
Filled up the tank to the very top on the filler neck (as always) then noticed that I had diesel leaking from under the car in the area of the filler neck. Took it to the local dealer to get in on a lift and they say the leak is where the filler neck meets the tank. They say the tank & filler neck are one piece (looks like that from the parts diagram) and that it's made of some type of poly/plastic material. Advised to replace the whole tank.

Took my car home to figure out the best course of action. It seems that now that some for the the fuel has leaked and/or been used (6 miles on tank), its not leaking anymore so maybe the leak is in fact right where the tank and neck meet?

Anyone out there have experience dropping the tank or have done a similar repair? I also found a 2" galvanized bolt in my driveway and I thought maybe this was from a coupler (if one exists) between the tank and neck - I cannot verify this from the low res parts diagram. There was a guy who posted about a similar problem, the post died I cant get in touch with the poster to see what their repair was.


New tank is about $1,200 online, some local junkyards have them too. I've got 200K on somewhat rough roads, but the rest of the car is not rattling apart, this just seems like a very unusual break? Any one else had a leaking tank? It's just too weird.

oh yeah, in full disclosure I did have a minor sideswipe near the filler area about 1 year ago, never leaked after that though and I always fill the tank to the very top of the neck.

Any advice appreciated!
 
Last edited:
Tim Birney

Tim Birney

Veteran Member
Joined
Dec 14, 2005
Location
Dearborn Heights, MI
TDI
05.5 TDI
ErikR said:
Filled up the tank to the very top on the filler neck (as always) then noticed that I had diesel leaking from under the car in the area of the filler neck. Took it to the local dealer to get in on a lift and they say the leak is where the filler neck meets the tank. They say the tank & filler neck are one piece (looks like that from the parts diagram) and that it's made of some type of poly/plastic material. Advised to replace the whole tank.

Took my car home to figure out the best course of action. It seems that now that some for the the fuel has leaked and/or been used (6 miles on tank), its not leaking anymore so maybe the leak is in fact right where the tank and neck meet?

Anyone out there have experience dropping the tank or have done a similar repair? I also found a 2" galvanized bolt in my driveway and I thought maybe this was from a coupler (if one exists) between the tank and neck - I cannot verify this from the low res parts diagram. There was a guy who posted about a similar problem, the post died I cant get in touch with the poster to see what their repair was.


New tank is about $1,200 online, some local junkyards have them too. I've got 200K on somewhat rough roads, but the rest of the car is not rattling apart, this just seems like a very unusual break? Any one else had a leaking tank? It's just too weird.

oh yeah, in full disclosure I did have a minor sideswipe near the filler area about 1 year ago, never leaked after that though and I always fill the tank to the very top of the neck.

Any advice appreciated!
Click to expand...
Possibly where the neck of the fill tube meets the fender... just a thought.
 
M

mctdi

Veteran Member
Joined
Dec 10, 2004
Location
se WI
TDI
2010 Jetta
ErikR said:
Filled up the tank to the very top on the filler neck (as always) then noticed that I had diesel leaking from under the car in the area of the filler neck. Took it to the local dealer to get in on a lift and they say the leak is where the filler neck meets the tank.
Click to expand...
Did you see the point of leaking?

Just asking - The leaking fuel was not overfill/spillage at the fill port, draining down?
 
R

radonlong

New member
Joined
May 19, 2015
Location
Kaneohe, Hawaii
TDI
Jetta mk5
There's a vent tube near the filler cap. The only access to it is through the cover. It can be capped to prevent further discharge.
 
Ol'Rattler

Ol'Rattler

Top Post Dawg
Joined
Jul 3, 2007
Location
PNA
TDI
2006 BRM Jetta
Hyde7278 said:
This tread is over 2 yrs old I'm sure it has been taken care of by now
Click to expand...
Astute observation. It would be nice to know the outcome....................

radonlong said:
There's a vent tube near the filler cap. The only access to it is through the cover. It can be capped to prevent further discharge.
Click to expand...
Plugging the vent on a fuel tank would cause the tank to collapse, wouldn't it? Sounds like a very bad idea.
 
R

radonlong

New member
Joined
May 19, 2015
Location
Kaneohe, Hawaii
TDI
Jetta mk5
Already plugged mine. I was looking for a solution to this leak for a couple of weeks but didn't find any. I didn't see any other crack either when I filled up. The result of the plug was longer range. i.e., more usable fuel than before. No spillage, less evaporation.
The tank is in no position to collapse to begin with. There's not enough force in the fuel pump to do so. However, if you are really worried about the tank collapsing, you can also put a pin size hole on the cap you will be using. Or, instal a new tank for $2000 at the dealership.

This post is basically for everyone who is running into the same situation. I didn't know about this until it started happening to me and I didn't find any other solution from any site on the web.
 
Last edited:
E

eztiger12

Active member
Joined
Sep 20, 2015
Location
Montreal, Qc, Canada
TDI
2006 Jetta TDI
Revive

I hoping to revive this thread,

I have the exact same problem when filling up my 2006 Jetta Tdi. When I get almost filled to the rim it will start leaking fuel (pretty steady) right behind the passenger rear wheel.

I was hoping it would of been the fuel sender gasket (found that on this forum) but no luck, it was clean as a whistle.

I understand that by blocking or caping the vent tube I can resolve this problem.

Can anyone PLEASE help on how to tackle this problem .......how do I get to the vent tube to cap it.

I have taken a look but don't see much......

It anyone has instructions how to or pictures it would be VERY appreciated.

his leak is starting to be a pain .....especially after you just resurfaced your driveway......

Thanks to all in advance
 
E

ErikR

Veteran Member
Joined
Feb 14, 2006
Location
Long Island NY
TDI
06 Jetta TDI pk2 5-spd Black/Black
Wow, just checked in to read up on the emissions cheat code fiasco and saw this thread up top.

Follow-up is that I never did anything to fix it except I no longer top off completely. I fill to the first pump shut off and go on my way. No leaked fuel at all if I fill like this, and range is not affected since I never run it even close to almost empty.

I have to look into the vent location diagram. Might be what i need to do to fix it. I did take it to the dealer at the time but in retrospect I never saw the car on the lift and verified the leak location with my own eyes. I don't trust the dealership's word on this, for all I know they saw fuel at the neck/tank junction that had traveled down from a higher up position.
 
T

tdiatlast

Top Post Dawg
Joined
Jan 21, 2009
Location
Fort Worth, Texas
TDI
2009 Sportwagen (boughtback); 2014 Passat TDI SEL (boughtback)
2 2/1 years ago? There can't be a crack anywhere in the system. Saved yourself a lot of aggravation and money by just ignoring the faulty diagnosis.
Glad you don't have a problem!
 
E

ErikR

Veteran Member
Joined
Feb 14, 2006
Location
Long Island NY
TDI
06 Jetta TDI pk2 5-spd Black/Black
No, I'm sure there is a leak in the neck - somewhere. Even since I owned the car I filled it completely to the brim, no spillage, and never had fuel leaking in the driveway even when parking it right after a complete fill up.

At the point I made this post something happened, where I would top off and and park right afterwards. Next day I'd notice a fuel leak on the driveway, a spill under the fuel filler area, about a 1/4 to half liter (or less). I'd also see a small a trail of fuel also up/down the driveway from backing in and then leaving.

Even since I owned the car this is how I filled it and never had a leak. Then one day this problem popped up so I just don't top off completely anymore. If I fill to the first pump shut off, and then park right away I get no spillage in the driveway, indicating that the leak location is high up on the filler neck.
 
E

eztiger12

Active member
Joined
Sep 20, 2015
Location
Montreal, Qc, Canada
TDI
2006 Jetta TDI
Thanks for the fast reply........everyone

Just came in the house now after inspecting the car concerning the leak and while I was at it I decided to change the Oil and Filter.

I use to always fill up to the rim until my last two fill ups ........all of a sudden the fuel started to leak from underneath as soon as I would top it off.

Well I tried my best to see where it was leaking put I'm still not 100% sure. The tank itself is pretty clean but I think its leaking from the filler neck but way high.

I first removed the fuel door (very easy 1 screw) to inspect the top of the neck. I can see a "L" shape nipple connected to the filler neck just right of the fuel hole.

I figured it should be a vent but there is no hose. I then needed to inspect further thinking the hose connected to the that nipple got loose and fell off and thats where the fuel in leaking from when I fill up.

I removed the wheel well liner to gain access to the nipple and the fallen hose but to my surprise ......guess what ....no hose.

From the evidence I would like to believe that the fuel is leaking from that nipple. I connected a vinyl hose and blew in it and there was restriction.

So what I did was I took about 1 foot of the hose and connected it to the "L" shape nipple and ran it higher than the Fuel fill up hole. I figured if that is where it was leaking from when filling up....is shouldn't anymore since it is now 2'' higher than the fill up hole.

I'll keep you posted on my findings, till than I am all ears since this has not been tested yet
 
E

eztiger12

Active member
Joined
Sep 20, 2015
Location
Montreal, Qc, Canada
TDI
2006 Jetta TDI
A 100% Fix

A fix that acutely took 15 minutes to do and probably a bigger fuel capacity.

Like I said in the previous post, I removed the fuel door (very easy 1 screw) to inspect the top of the neck. I can see a "L" shape nipple connected to the filler neck just right of the fuel hole.

So what I did was I took about 1 foot of the hose and connected it to the "L" shape nipple and ran it higher than the Fuel fill up hole. I figured if that is where it was leaking from when filling up....is shouldn't anymore since it is now 2'' higher than the fill up hole.

Bingo I fuel up last night until the last drop and you got it........not a single drop on the floor.......dry as a whistle. I was practicaly jumping up and down with joy.

There is obviously something that was there before and fell off but what exactly I dont know

Would love to know if it works for others please post
 
E

eztiger12

Active member
Joined
Sep 20, 2015
Location
Montreal, Qc, Canada
TDI
2006 Jetta TDI
Something I forgot to mention........on that last fill up that I was talking about in that last post.

I also beat a personal record on the amount of fuel I pumped into the tank. I was never able to put more than 52 litres (13.7369 gal) in the tank and this time I was able to put 55 litres (14.5295). Was I running on fumes????

Was it because I never made my tank go that low or is it because of the mod I did. I will keep you posted.
 
E

eztiger12

Active member
Joined
Sep 20, 2015
Location
Montreal, Qc, Canada
TDI
2006 Jetta TDI
For all of you out there with the same problem..........it is finally solved on my VW. More than 3 fill ups not even a drop of fuel on the floor.

I would love to hear if this info helped anyone else.

Thx
 
T

TDI-Tom

Member
Joined
Nov 20, 2002
Location
Arizona
TDI
2015 2.0L Passat
O.K. This is in response to an old post...I've been looking for a solution to *exactly* the problem described here. One day while filling my 2015 Passat, I thought I heard a faint "crack" or "pop" and when the filler neck was full, like usual, I stopped filling....then noticed the fuel leak forward and inside or right rear wheel.

Once I got home a closer inspection made it appear as though there was a fuel leak where the filler is attached to the tank. OK I'll check again later...next fill up, same result.

This time a closer inspection made it obvious the excess fuel was following the filler down from the fill port and was NOT originated from the fuel tank connection.
While awaiting and looking for solutions, I no longer fill to the maximum and there is no spilled fuel.

I am now actively seeking how to fix this leak in the filler. I might take this to the Dealer this week, but want to go informed so I can tell if I'm getting a straight story from them.
 
A

All of Us

Ian's Dad
Joined
Nov 14, 2005
Location
Brookfield, IL
TDI
2015 NMS Passat SE TDI "Gin" 2006 A5 New Jetta TDI "Graycie" and 2003 A4 Jetta GLS TDI "Liath"
I just posted a new thread on what appears to be this same problem. Searched for this before hand too. Oh well. I have owned my 2015 Passat for over 2 years and have never had it leak like this before, and I always filled it right up to the rim of the filler hole on previous fill ups. Today was different though since it leaked all over the ground at the fuel station as I was topping it up. I believe it is leaking somewhere high up in the filler neck and may in fact be leaking at this "L" shaped nipple on the filler neck that eztiger12 is referring to. I can't confirm this though since I have not pulled anything apart yet. Maybe I will just follow ErikR's lead and only fill until the pump nozzle does the auto-shutoff thing. Since both methods seem to address the leak issue.
 
You must log in or register to reply here.
Top