JWILLI

I have a 2004 996TT with about 85k miles on it. I have owned it since September 2017. It needs some love but not bad overall. Two issues: one solved and one I need some help with. The first was a clunking front passenger strut over bumps. Take a look at the top hat..That was easy.



Next question and where I need help. When I fill up the fuel tank, just until the fuel nozzle clicks off, I get fuel puddling on the underbelly pan and the garage reeks of fuel. This persists until I get down to about a 3/4 tank of gas. This has been the best thread on my problem: https://rennlist.com/forums/996-turb...way-valve.html




I have changed the fuel neck gasket and I still have the problem:





Here are some tank pictures:






It looks like it is wet around the whole fuel neck opening. Even above the opening. The tube above the opening is to/from the evap canister. Any ideas? New tank? Or is the the evap tube leaking? Does that evap line have fuel in it or just vapor?

Jason

2019 EDIT: Replaced the fuel tank and it fixed the problem. Peace out.

poivaw

Had similar problem and had to replace the tank

Jferrante

replace the seal around the sending unit before replacing the tank....if it isn't leaking at 3/4 full it is obviously coming out closer to the top of the tank

JWILLI

POIVAW - What was the issue that necessitated replacing the tank? I don't like the looks of the whole steering rack on the ground behind your tank.

Jferrante - It is dry all around the sending unit. I am hesitant to start throwing seals at it.

poivaw

we found cracks on the tank

JWILLI

Thanks. Guess I am going to drop the tank. I will let you all know what I find.

fpb111

Check the vent line. I would think if it were cracked you would be getting CEL450 or other evep code, purge or vent valve. Because the ECU pulls a vacuum on the tank/charcoal can/recovery lines when it checks the evaporative recovery system.
https://www.yourmechanic.com/article...lerie-johnston

JWILLI

Hell that is a great point. I just pulled the codes and none active or pending. Maybe the tank is not cracked and it is a hose. Still not sure which or how....

POIVAW - Did you get any codes with your cracked tank?

poivaw

No code

fpb111

Smoke test?

JWILLI

Figured I would give an update. I started tearing into the car several weeks ago to get the tank out. Weekends are busy so I have been nibbling at the job a little at night during the week. Sucks that the car is down for the summer but I am trying to make a track day in 3 weeks at Mid-Ohio. Not looking good depending on the lead time for a new fuel tank (if I need one. I am hoping it is a vent line or split hose or something stupid.)

Might as well replace the radiators while I have all of the coolant drained. New CSF units.

Old ones were pretty nasty. They looked clean of large debris when looking through the grill but .. here I will show you. I was amazed at how packed that dirt was in the fins.




Here is where I got tonight. Subframe lowered. Working on the two plastic clips under the fuel tank that hold the two coolant lines. I need smaller hands.....

powdrhound

If you need a new 996TT tank, I have one in storage that I don't need. Perfect condition...

JWILLI

I got the tank out. Not sure where the problem is as there are no obvious cracks. I stuck the fuel filler neck into the opening and tried to pry in different directions to see if there were any cracks that opened and I did not find any. This was a bear of a process that I don't want to repeat. Thanks to John for sending me a new tank to install. I am wondering if I should replace the fuel filler neck just to be 100% sure the problem is solved. I am at a loss for the moment.



You can see the amount of crud that developed on the passenger side of the tank. Most of the components on the passenger side of the car were covered in that oily dirt. I am going to spend an evening scrubbing the car down even though I think I got most of it already.... on my hands, clothes, and in my hair.





And I am thinking of writing a song about how much I hate radiator fluid. Every time I think I got it all, I would bumped an open radiator hose and get covered in it. I have about 7 gallons of it in buckets and about another half - 3/4 gallons on me.

powdrhound

Tank should arrive tomorrow at your doorstep my friend. Good luck getting it all sorted. Not a fun job for sure...

JWILLI

Thanks John. Again I greatly appreciate your generosity! And I am learning a lot about this car. There pretty much won't be a nut left unturned on the front end.

Anyone have any ideas on tests to figure out what the problem could be? I put the fuel filler neck in and the rubber gasket internal to the tank opening held the aluminum neck pretty snug. I am beginning to wonder if it was the fuel filler neck gasket all along....

I am thinking of taking fpb111's advice and smoke testing this tank. I can see every inch of it now so that should answer some questions. Any recommendations on a smoke test kit?