by "twochevrons" (twochevrons)
Published 02/26/2017 at 12:30
by "twochevrons" (twochevrons)
Published 02/26/2017 at 12:30
Tags: audi
; allroad
; overengineering
; complexity
; fuel tank
STARS: 7
This is the fuel tank used in the C5 A6 Quattro and Allroad. Multiple level senders, an internal siphon system to transfer fuel between compartments, and a hole in the middle (for the rear differential). I am in equal parts horrified, in awe, and completely unsurprised.
This may explain the extreme nonlinearity of my Allroad’s fuel gauge... Between that and the 2.7T’s incredible thirst, anywhere below 1/2 means “fill the hell up NOW.”
"The World of Vee" (theworldofvee)
02/26/2017 at 12:32, STARS: 1
I have a buddy that completely stripped his C5 down to the chassis and was respraying it shark gray and he said the fuel tank was one of the hardest parts.
He never finished his project though :(
"DipodomysDeserti" (dipodomysdeserti)
02/26/2017 at 12:34, STARS: 6
What the fuck is actually wrong with this company?
"BugEyedBimmer - back in the Saddle Dakota Leather" (bugeyedacura)
02/26/2017 at 12:36, STARS: 8
The bean counters get their way at all the wrong times so the engineers take it out on the cars when and where they can.
"Dr. Zoidberg - RIP Oppo" (thetomselleck)
02/26/2017 at 12:38, STARS: 6
I disagree — there seemed to be intentional engineering to design parts to fail since 2001. Plastic timing chain guides that cost $8k to service comes to mind.
"That Bastard Kurtis - An Attempt to Standardize My Username Across Platforms" (thatbastardkurtis5)
02/26/2017 at 12:40, STARS: 1
And I thought the allroad’s suspension system was obtuse. Though until very recently, an allroad was the single best car I ever owned.
"Dave the car guy , still here" (a3dave)
02/26/2017 at 12:46, STARS: 2
Oddly enough the C5 Chevy Corvette also has dual tanks with all the required extra plumbing. Bizarre coincidence or crude engineers joke on all of us?
"twochevrons" (twochevrons)
02/26/2017 at 12:50, STARS: 1
I’ve been thrilled with mine. I used to own Citroëns, so to be honest, the air suspension isn’t all that bad from my perspective. Basically the same idea as Citroën, just with simpler (though inferior) execution.
It’s not been all smooth sailing – the power windows only work when they feel like it, I’ve had to become very familiar with the dreaded service position, and every time I fix air suspension issue, a new one crops up – but it’s fantastic to drive, and hilariously capable in the snow. Given how cheaply I bought it, I can forgive an awful lot of faults.
"Leon711" (leon711)
02/26/2017 at 12:51, STARS: 1
I don’t think it is, the Sinclair C5 doesn’t even have fuel tanks.
"Dave the car guy , still here" (a3dave)
02/26/2017 at 12:52, STARS: 1
Chevy C5 Vette and some Lotus Esprit had it too. Some engineers are nuts. There are BMW that have a single tank straddling driveshaft that need dual pickups. Just odd solutions due to space confinements. Subaru had something weird like that on some models too.
"twochevrons" (twochevrons)
02/26/2017 at 12:55, STARS: 2
Jaguar did it too, but they just had two entirely independent tanks, and had the driver switch between them manually. Far cooler, in my opinion.
"Dave the car guy , still here" (a3dave)
02/26/2017 at 12:59, STARS: 1
Had forgotten about that. Had seen it before. Thats actually way cooler because you can fill car from either side. Also if you had bad fuel in one tank you could drive off the other side until you cleaned out the contaminated stuff.
"twochevrons" (twochevrons)
02/26/2017 at 13:00, STARS: 1
I’m inclined to agree. I like to think that the ridiculously elaborate folding cup holders are the engineers’ revenge for the horrible soft touch plastics that peel and look awful if you so much as think about touching them.
"twochevrons" (twochevrons)
02/26/2017 at 13:01, STARS: 2
Let nobody say that engineers don’t have a sense of humour.
"BugEyedBimmer - back in the Saddle Dakota Leather" (bugeyedacura)
02/26/2017 at 13:03, STARS: 0
How is that not a bean counter decision? plastic guides are much cheaper and last the length of warranty in most cases.
"twochevrons" (twochevrons)
02/26/2017 at 13:04, STARS: 1
On the other hand, I hear that often people would just use one tank and ignore the other, leading to it rusting out :(. Doesn’t detract from the cool-factor, though.
"Dave the car guy , still here" (a3dave)
02/26/2017 at 13:04, STARS: 0
But there is a rare dual battery version.
"PS9" (PS9)
02/26/2017 at 13:05, STARS: 1
Something wrong with Audi? Surely you jest.
"twochevrons" (twochevrons)
02/26/2017 at 13:11, STARS: 2
I just remembered that Volvo did it too, on AWD equipped versions of the 1998-2001 V70. I believe they used an electric pump to transfer fuel from one section of the tank to another.
The other fun thing with those cars is that there’s no access to the fuel pump without removing the tank, which requires also removing the whole rear subframe. With how they have depreciated, having one of the pumps go bad is enough to write off the car. The DIY solution is to just cut a hole in the floor in exactly the right spot, which scares me somewhat.
"Dave the car guy , still here" (a3dave)
02/26/2017 at 13:11, STARS: 0
Dual tanks in exotics are even more common. Would take some searches to figure out exact models but some GT40, Lamborghini, Maserati and many Ferrari models have dual tanks as well.
"Dave the car guy , still here" (a3dave)
02/26/2017 at 13:15, STARS: 0
Not surprised. GM trucks with dual tanks in more recent years use the same solution instead of a tank switch. The transfer pump equals tank levels and the twin fuel level sensors give an averaged reading to the cluster. Really pisses off the DIY crowd when they have trouble diagnosing which level sender has failed.
"That Bastard Kurtis - An Attempt to Standardize My Username Across Platforms" (thatbastardkurtis5)
02/26/2017 at 13:22, STARS: 0
They really are excellent in the snow. I had mine for 4 years and about 70k miles and all it needed was tires and oil changes, then at 150k miles or so everything went at once.
Alternator died, so I figured I’ll need to take the nose off anyway so I may as well do the timing belt while I was in there. Then while it was up in the air two of the (original) airbags cracked and wouldn’t hold air anymore. I sold it in that condition and did really well on it, the timing belt just being done helped a lot.
"Dr. Zoidberg - RIP Oppo" (thetomselleck)
02/26/2017 at 13:24, STARS: 1
Bean counting: plastic guides
Bad engineering: putting the timing chain in the back of the engine with plastic guides
"Stephenson Valve Gear" (stephensonvalvegear)
02/26/2017 at 13:55, STARS: 6
Ya know, occasionally I’ll think to my self, “Valve Gear, your prejudices against Audi and Volkswagen are outdated and without merit. They surely aren’t the over-engineered Rube Goldberg contraptions of yesteryear. Why not give them another chance?”
...and then I see something like this that reinforces my biases against them all over again.
"twochevrons" (twochevrons)
02/26/2017 at 14:07, STARS: 2
There must be something wrong with me. Things like this just perversely make me like them all the more.
"bhtooefr" (bhtooefr)
02/26/2017 at 14:11, STARS: 0
The Passat W8 has an identical setup... but with a THIRD section in the spare tire well, because it’s even more thirsty.
https://www.drive2.com/l/4593919/
"Ike" (untitledcarshow)
02/26/2017 at 14:53, STARS: 0
Iirc if you had a AWD V70 the fuel pump was in accessible. If you had a 2WD you could do it with a hatch in the car. Which was in the same place but basically a middle finger to the people who had the AWD ones
"Twism" (Twism069)
02/26/2017 at 15:13, STARS: 0
I especially loathe this.
And I’m guessing you can’t service either the pump or the siphons without removing the tank?
VAG, this is why your mechanics hate you.
"shop-teacher" (shop-teacher)
02/26/2017 at 15:54, STARS: 0
That’s the most German thing I have ever seen in my life.
"BugEyedBimmer - back in the Saddle Dakota Leather" (bugeyedacura)
02/26/2017 at 16:14, STARS: 0
Correct. But let me play devils advocate. Would it be bad engineering if they didn’t fail like they do? So if they weren’t plastic and therefore didn’t have to be so often maintenanced, would that even be an issue?
"pip bip - choose Corrour" (hhgttg69)
02/27/2017 at 06:28, STARS: 0
now you see why i wouldn’t touch a VW group product with a barge pole.
"BiTurbo228 - Dr Frankenstein of Spitfires" (biturbo228)
04/06/2017 at 08:00, STARS: 0
...what the hell is that? I must admit it’s moments like this that make me really glad I’ve limited the majority of my mechanical work to cars that were designed pre-1990 ;)
"twochevrons" (twochevrons)
04/06/2017 at 19:10, STARS: 1
So much of that car gives me that reaction. It’s awesome when it’s not broken – unstoppable in the snow, and far quicker and more chuckable than its bulk would suggest. But boy, Audi really know how to overcomplicate things.