Is this the supply or return fuel line?

[Luxus Panzer]

The one that's all crunched up.

I will explain what happened later ;)

For orientation you can see the wheel in the one picture that is the front passenger side wheel the line that is in good condition is on the outside of the car. The crunched up Line is towards the middle of the car.








The car idles just fine as is but I'm going to have to splice in a repair to this line regardless.

Are the lines on these cars plastic or metal ones I cut into them?

If it is the supply line when I cut it open is the entire fuel tank going to drain out?

Same question if it is the return line is everything going to drain out?

Bad day so far, thanks in advance.

[Let it snow]

No return line on the 1.8t. I think it is either supply or gas tank evap line.

[old guy]

The line on the inside is the fuel line. The line on the outside is the Evap purge line. Clicky click®

[Luxus Panzer]

Thanks, supply line it is.

I know I need to fix this is the line is seriously kinked, however, I just do not have time this week.

Am I risking anything bad by a possible lack of fuel? She idles just fine. I also took her for a drive...she was fine. I then did a 3rd gear pull to redline to demand as much fuel as possible...no issues. I logged the pull below...



Everything look hunky dory?



As long as these lines are metal (are they?) then I will ust cut out the bad section and patch it with fuel injector hose with a I.D. the same as the O.D. of the fuel line. Then X2 fuel line clamps at each end. I have done this fix many times on many cars and it always holds up well.

I also have a full tank of gas and I am wondering if when I break the fuel supply line open...if the entire tank is going to siphon out on to my floor? Anyone BTDT?

[old guy]

Fuel trims look spot on. No worries. Fix it when you have time. Just have a cap ready for when you cut the metal fuel line section and you should be able to minimize the spillage. Have everything already in place for a quick repair and it should be pretty straight forward.

[Seerlah]

It is rubber coating with aluminum tubing underneath. For a quick band-aid so you can drive her still without blowing your motor, cut the kink/crushed line and use fuel injection (or screw clamps with rolled edges) with 5/16" fuel hose till you have time to fix it. You can even do something like place it through conduit (black pipe of something stronger may be better; winging it) with cushion clamps to the chassis for better chance of the rubber line staying safe from the elements till a proper fix.

The problem is you are fine at idle. But that crushed line is creating a huge restriction. The more air your engine needs for combustion, the more fuel it needs. Not also in volume, but in proper pressure. That compromised line no doubt will compromise both when the ECU requests more fuel for the injectors to spray. This in turn will make you run incredibly lean and damage your engine. But car would run like poop and most likely cut off if you run into that situation, due to not having enough fuel for combustion to drive the pistons.

Just cut off that section and add 5/16" cheap Autozone fuel hose (will cost like $1 for the hose, then price of clamps). This will at least have your engine not be placed in a situation that can damage it's health in more cases than one (ie burning your piston rings and lowering compression from running lean).

Fuel trims look spot on. No worries. Fix it when you have time. Just have a cap ready for when you cut the metal fuel line section and you should be able to minimize the spillage. Have everything already in place for a quick repair and it should be pretty straight forward.

Even though that "one" 3rd gear log looks ok, the looks of that line puts me in a mind state of better safe than sorry. Especially for a band-aid that will cost like $5 and 30 min of work. Variables change, and I feel it just isn't worth chancing. This is what I would have done anyways, if it happened to me. Pushed my luck with too many things over the years. Win some, lose some. But the losses can come with regrets that cost unwarranted extra expenses because it could have been avoided, which only brings more regret, frustration, anger, etc. Damaging domino effect to your well being. Been there one too many times, and why my Audi has sat on my driveway unmoved for a couple months now (have a work van now I bring home, which is why it sat way longer than it should. plus I have another car).

[old guy]

I sure can't argue with your logic, Mitch. I was looking at the hose and although it looks like crap it didn't appear to be kinked flat anywhere. But you are right. Better safe than sorry

[Luxus Panzer]

I will keep her under 3K RPM this week.

I have all the supplies to splice in a fix.

What is the best way to cut the lines?

Dremmel makes a bunch of sparks.
Small rotary pipe cutter is too slow and gas will get everywhere.
I have a small air saw...this may be the ticket.

Any ideas for what to use to cap off the lines while I work? I dont want to dump gas everywhere

[Seerlah]

I could totally be incorrect and he could ride like that into the sunset for years to come without a hiccup. But for a $5 insurance, I feel it would be the more prudent route.

I will keep her under 3K RPM this week.

I have all the supplies to splice in a fix.

What is the best way to cut the lines?

Dremmel makes a bunch of sparks.
Small rotary pipe cutter is too slow and gas will get everywhere.
I have a small air saw...this may be the ticket.

Any ideas for what to use to cap off the lines while I work? I dont want to dump gas everywhere

Take line out from it's OEM clamps (for working space) and use a standard pipe cutter with small cutting wheel.

[old guy]

Small pipe cutter for sure. You don't want to be getting any metal chips in your fuel line.

[Luxus Panzer]

is the fuel going to stop after the fuel caught between the pump and the fuel rail drains....or will the entire tank empty when I break open the line?

[Matt Devo]

is the fuel going to stop after the fuel caught between the pump and the fuel rail drains....or will the entire tank empty when I break open the line?

how would the tank drain without the pump running?

[Luxus Panzer]

how would the tank drain without the pump running?

Syphon ?

[hightime80]

He must have the special model of a4 where the tank sits up in the trunk as redundant feature in case of a fuel pump failure😝

[Luxus Panzer]

He must have the special model of a4 where the tank sits up in the trunk as redundant feature in case of a fuel pump failure😝

No, but the fuel lines do sit well below the level of fuel In the tank.

[Matt Devo]

No, but the fuel lines do sit well below the level of fuel In the tank.

the fuel would still have to make its way past the (non-operational) pump. When you remove/replace the filter, or a line is cut, the only fuel that will escape is that already past the pump. As mentioned previously, you should discharge any built up pressure (and fuel) via the bleeder valve on the back of the fuel rail, and prepare for some drip when you cut the line for repair. Honestly though, the damage looks pretty minimal, I'd be tempted to just coat it with some truck bed liner and call it a day.

[Luxus Panzer]

the fuel would still have to make its way past the (non-operational) pump. When you remove/replace the filter, or a line is cut, the only fuel that will escape is that already past the pump. As mentioned previously, you should discharge any built up pressure (and fuel) via the bleeder valve on the back of the fuel rail, and prepare for some drip when you cut the line for repair. Honestly though, the damage looks pretty minimal, I'd be tempted to just coat it with some truck bed liner and call it a day.

Good to know that it will not all drain out.

I am going to play safe than sorry tonight and splice in a fix.

Good call on the valve on the fuel rail...I will stick a rag over that bad boy and bleed off some pressure

[Luxus Panzer]

How the hell do I get a bleed valve at the end of the fuel rail to vent the fuel I pushed pretty hard nothing happens do I just push harder?

[old guy]

How the hell do I get a bleed valve at the end of the fuel rail to vent the fuel I pushed pretty hard nothing happens do I just push harder?

If nothing happened it means the fuel pressure has already gone to zero.

[Luxus Panzer]

So I just push in the nipple that sticks out once I remove the cap on the fuel rail?

I also pulled the fuel pump fuse and attempted to start her she would even fire up

[old guy]

So I just push in the nipple that sticks out once I remove the cap on the fuel rail?

I also pulled the fuel pump fuse and attempted to start her she would even fire up

Yes, just push the nipple. It's just like letting air out of your tire.

[Luxus Panzer]

Lol, I could not get my fuel rail to vent fuel for the life of me. I decided to just start the car up, then pull the fuel pump fuse while it was running. This worked as when I cracked the line I had less than 2 OZ of fuel come out.

Small pipe cutter was the right tool for the job, simple clean easy cuts.

Here is the section I removed.



Here is the size of the hose pre crunch ;)



and after.....not good...



Yes, MM (millimeters), because imperial blows ;)

Here is the patch...Feels like working on a B4 again ;) (B4s had no coating or plastic cover over the lines so they always rusted out at the clamps.) It was a shame that the fix had to run thru a clamp, but there was no avoiding it. Got it all clamped back up...nothing zip ties wont fix ;)



Did another 3rd gear pull with the line fixed....not much change..



Also took the opportunity to fix all the holes and cracks in the plastic cover under the car from when it 1/2 fell off this winter...used some fiberglass cloth and resin...worked out quite well for anyone looking for a way to fix up their plastic under-covers.

Thanks for the guidance all.