Massive fuel leak

Odezza

New member
Joined
Dec 26, 2024
Location
Milwaukee
TDI
2014 A8L TDI
Driving home tonight was uneventful until I went to exit the freeway. My brakes just were not cooperating! As I managed to bring it to a stop a cloud of diesel smoke curls forward and suddenly that wonderful smell of raw fuel is in the cabin. ***! I just did an oil change on it yesterday. 2014 A8L TDI. Not sure where to start looking, someone said high pressure pump seal but I just drove it 1000 miles the last few days. The underside of the cover on the Right side was wet, the Left side is dry. I have pooled fresh diesel all over the injectors, crevices and assorted bolts over there. Left quite a trail of fuel up the driveway, cant wait to see what my garage floor looks like tomorrow...or smells like for the next year. About a mile away from home the glow plug light starts flashing. More stuff to look into. I'm pretty sure the warranty is still in effect from the software upgrade, just 91,000 miles on it. Any ideas on where to start looking would be helpful. Neighbor says cold weather can affect the high pressure pump seal, not sure where that seal is or what the pump looks like. Compared to my 300SD's this is an incredibly complicated engine. I could figure it out I suppose, hoping its just return lines but to lose that much fuel so fast is a challenge.

Both wheels have dripping fuel. New brake pads maybe are needed. Guessing the leak accumulated in the belly pan and sloshed to both sides.

DIagnostics, have the wife start it while I try to figure out where she's losing her liquor? Seems excessive for return lines. Has anyone seen anything similar? Any clues appreciated. I'll fix easy stuff, but I have no background on the technique to properly deal with these high pressure systems. The pressure concerns me a lot, don't go looking for leaks with my finger if I can get it running. Do the fuel lines loosen up or crack?
 

STDOUBT

Veteran Member
Joined
Jul 30, 2007
Location
Portland, effing Oregon
TDI
dos jettas
don't go looking for leaks with my finger if I can get it running.
I'd wear a face shield if I was going to oogle at that motor while it runs.
I think a smarter idea would be degreasing/cleansing your engine bay, dry it really well, then with the hood down run it for a sec, turn it off and go hunting.
 

oilhammer

Certified Volkswagen Nut & Vendor
Joined
Dec 11, 2001
Location
outside St Louis, MO
TDI
There are just too many to list....
There is an updated fuel return hose assembly on the V6s, it goes into the passenger side rail, near the front of the engine, not very far from the oil filter. There is a banjo connection there.

You really have to just visually start looking, and maybe have someone start the engine and be ready to shut it back off right away.

Yes, they are a complex engine. And the fuel system is all over the place on top.
 
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