[capt_slow]

Over the past year I've noticed a faint fuel-like smell coming from the driver-rear wheel well. I never could figure out where it came from, but it always comes back every so often. About 8 months ago, the dealer had a look around the fuel tank as well and found no leaks.

I came across an old issue on the F30 that is apparently common. The location is approximately the same place where I smell the odor. Is such a leak possible on the diesel LCI F31?

If so, I guess the dealer couldnt see the leak without dropping the tank. Is there enough space on the top side of the tank to wiggle a endoscope to that area without dropping the tank itself? Was planning to take a few pics and if there is a leak, get it fixed under warranty.

[capt_slow]

I lifted up the car, removed the underbody paneling covering the driver-side of the tank. It looks clean, but there is still a faint fuel-like smell coming from the fuel line area. Couldn't get a clear view of the top side of the tank from the endoscope. Smells a bit different than the diesel from the filler neck that's for sure.




Also while I had the car up on the air, I had a look at everything else and found out the panel covering the fuel filter is damaged. Last touched by an indy shop when the fuel filer was replaced.

[Enabled]

While I think it takes very little diesel to produce a smell to a good nose (think fuel filter spills, fuel cap droplets, etc), I am curious of your findings. Mine has a mild smell here and there, but I found no leaks.

[Mikej0h]

Fuel filter is also on that location.
it's at the middle of the car left side, after you remove the under tray.
Perhaps that has some (old) diesel (... or the tray itself) that has some blow by of air.

[capt_slow]

Originally Posted by Mikej0h

Fuel filter is also on that location.
it's at the middle of the car left side, after you remove the under tray.
Perhaps that has some (old) diesel (... or the tray itself) that has some blow by of air.

I put the car up in the air again and looked around the fuel filter, it looks clean:



I pulled the rear-driver wheel and took a more in-depth sniff test and it's definitely coming from this area near the rear subframe mount. Brake lines look clean and the bleeder valve is clean too:


I took a clean rag and wiped the fuel tank where I could, all that came off was just dust. I'm more perplexed by this every time I look into it.

On another note, that indy shop must have lost a few screws when they took off the splash shield for the fuel filter change, as I found two of these silver ones holding it up. Thankfully, I have a few proper spares to put back in.

[BurrNinja]

Does this help?

[capt_slow]

Originally Posted by BurrNinja

Does this help?

Not quite, that video is how I ended up in this rabbit hole.

I wanted to see if there was a way to see if the tank was leaking without dropping the tank itself. I've since learned it's impossible, but I've also tore deep enough into the car to think the smell isnt coming from the tank. I took off the wheel and did another sniff test and it's almost as if the smell is coming from the wheel arch liner.

[wysodzky_]

I have exactly the same problem. No leaks, nothing. I dropped the fuel tank, I even added epoxy on all of the connections. I didnt notice any leaks, all lines good, fuel filter also. Still I smell some diesel near driver rear arch area... After time it goes away. Did you resolve it maybe?

[cezar22]

For the last 2 years my car dumps diesel after I fill it up. I tried pulling the wheel well liner and replacing the rubber connector b/w the filler neck and tank. No improvement.

[wysodzky_]

Does it spill on left side or right side of the car? (Looking from behind)

[cezar22]

Right side for me. Basically in the filler neck area.

We probably have separate issues but I find it interesting nonetheless.

[wysodzky_]

Ok so if you changed the rubber connector it looks strange. Only filler neck then might have some small crack or something...
I dont thing breather pipes might leak the fuel.
In my case when the weather is colder I dont smell diesel. I will try to change fuel tank to newer one(mine is 2014). Will update if this helps.