God knows how I desperately want it to be the inlet hose and I still have
some hope it will be. I'll have it checked tomorrow morning, so your
opinions are greatly appreciated - given the kind of dealers here one never
knows if you might be cheated into buying a new turbo when that was not
necessary at all.
Symptoms are as follows:
Continual observance of warm-up and cooling-down procedures from day 1 of
buying the car new.
What happened yesterday was some mixed-condition driving: Some 1/2 hour on
dual-carriage way, lots of frequent boost because of heavy traffic, avg
speed 130 kph. Then some 1/2 h up a mountain pass - non-spirited, some 1/2 h
downhill, perfect turbo cool-down. It was only when I was getting home that
I went without boost when attempting to overtake in fifth gear. Repeated
attempts showed very little or no boost was present.
No funny noise whatsoever, emissions seem to be OK, max power restricted to
the normal aspirated engine range or at most to stock range - my perception.
Engine behaves normal and no lights went on on dashboard but there is only a
little - but steady - boost only in the 1,300 to 2,000 rpm range.
Fair enough to mention I'd been seeing a small amount of surging under full
throttle in 5th gear since day 1 of chipping (from 56k miles to 75k) and
always-present pinging at 2,000 rev mid-throttle on slopes.
Since the turbo is still spooling, the worst thing might be a broken
wastegate rod, but I keep my fingers crossed and hope it's the hose.
Did it feel almost like hitting a brick wall when the revs were piled on? If
that's the case, then I'd say that it's almost certainly the hose either
crushing or a combination of crush and slipping off of the metal pipe
(something else that has been observed)
If the car feels down on power at odd times, then you might consider
replacing the DV.
I replaced mine at something like 800-1000 miles with a Forge unit -
response was instantly and noticeably better, indicating a failed DV (but
without the infamous goose-honk). The hose will get replaced once the car
gets back from the body shop (thanks, dear neighbour of mine, for driving
into my car when parked on my own driveway..)
Best bet for yourself, I think, is to check that the hose is tight at both
ends, and maybe consider a DV swap (can't remember the age of your car, so
I'm not sure of you have Bosch's latest attempt fitted) IIRC an aftermarket
DV should be in the region of GBP 85, and is a 5-10 minute job to swap.
Err... that's an interesting description. My wife's A2 1.4TDi exhibits
a 'goose honk' everytime you open the throttle to pull away from rest.
I presume that a TDi has a DV - is it likely that it has failed?
The only other possible symptoms I could point at would be less 'go'
than I would like below 2000RPM (above that it really takes off), but I
assumed that this is standard for a small TDi. Also the fuel
consumption is significantly worse than I had expected (average 50.8,
according to DIS), and 70mph cruising at around the same value (which
doesn't tie in with the official figure of 78.5 extra-urban). I like to
think that my driving style is reasonably economic (my RS6 is currently
showing 23.4 average on the DIS!).
All figures here are based on imperial gallons!
Peter Bell - email@example.com
Check whatever it is that JFP is saying first (must confess that I couldn't
follow the abbreviations)
On a TT (YMMV ;o), the DV is a small chunk of plastic, something like (from
memory) 1.5-2 inches in diameter, just "south" of the main inlet hose.
The honk is caused by the membrane fluttering when it should be sealing.
Makes a big difference to performance (can't remember the MPG, though)
As I understand it, JPF's acronyms refer to:
MIL Malfunction Indicator Light or similar.
MAF Mass Air Flow sensor
TDI Turbo Diesel electronic Injection
VAG Volkswagen Aktiensgesellschaft or the Diagnostic tool that Volkswagen
Ltd. uses to check on their cars.
My two cents,
Yep, will do - but I doubt that it's the MAF, the car had only done a
few thousand miles when the 'honk' was first pointed out to me (by my
salesman), and I can't believe the MAF 'honks'. However, the MAF could
be responsible for poor consumption and lack of power at certain points.
I didn't get 'MIL', but JPR is probably right on that one!
Oh, I know what a DV looks like - I fitted Forge DVs on my A6. I just
haven't looked to see whether I can find one on the A2.
As an aside, I have chatted (separately) to a couple of the Audi tuning
gurus about swapping DVs on the RS - the advice is that the standard
units fitted are pretty good and don't need to be changed unless
Performance affected at any particular revs, or throughout the whole
range? Once the revs get to 2000 (up to around 4600), the little car
does pull quite well (it is only 1422cc, 3 cylinder, after all), but it
is a little 'flat' below 2000.
I guess I could look on ETKA for presence of a DV! I should also get
around to connecting up my VAG-COM to check for fault codes.
Peter Bell - firstname.lastname@example.org
IIRC, power was down across the entire boosted range, but more apparent at
what should have been peak boost (OTOH, the standard TT 225 curve is pretty
flat, so that's not a great surprise)
Mine didn't honk before replacement - I just noticed that the car was
performing below the quoted figures. Changed the DV, and the car was
If it is a DV, then I doubt that there's much that could be read from a VAG
unit, assuming that you don't have access to any figures from a known-good
I suppose he could still have his A2's torque measured on a roller and
compare that to stock specs, after all it hasn't been chipped.
Then, again, by means of the VAG-C unit, and since latest stock turbo Audis
boast about an almost flat torque curve, he could check to see if there are
any crooks that might indicate some kind of sudden boost changes?
I am seriously considering getting a Forge DV myself, but for one thing
VAG-COMs are very rare here, and for another I'm not so sure what benefits I
could get from it.
I was talking more about a direct comparison - just to see if there *really*
was a problem
..back to that RR, I'd say. Any slip on the rollers is much more
None, unless there's something wrong.
If an aftermarket outfit says you can get a (measurable!) performance hike,
then ditch 'em. If they say you /might/ just increase reliability - if
you're lucky - well, then, listen ;o)
They might still be wrong - but it's all down to the reasoning..
..personally, my two biggest Audi upgrades were: 1) working-as-specified-DV,
and 2) tyres-that-connect-to-the-road-via-something-more-than-habit.
ContiSport tyres are probably good as /something/ on TTs. Not sure what..
bit big for ashtrays.. bit uncomfortable as seats.
Certainly no bl**dy use as tyres, unless all you're doing is making sure
that the floorpan is above the ground and you want something round-and-black
ContiSport/Audi. Hmm... fish/bicycle, female/UK clergyman (ducks behind
 Best in "willing-but-pointless" category - up to this point - were the
very Italian Pirellis on my Fester, which gripped better in the dry than an
Inland Revenue inspector, and were about as reliable as a 10-year old
Allegro (but with none of the saving graces). Perfectly happy with dry
performance (assuming that you're the sort of person that, upon surviving a
plane crash in the middle of a sea/Staines reservoir, doesn't mind if
your lifejacket has a leak), but about as useful as a sherbet umbrella in
the wet. Tip: best observed from outside the car ;o)
 No, I can't, either. Answers on a postcard..
 Where else are you going to get a chance to try out that lifejacket
between Heathrow and Edinbro'. Assuming that someone's not nicked it. [The
lifejacket, that is..!].
Could you elaborate on why you did fit Forges into your A6? And I guess that
must be another A6, not your RS, so is it the 2.7T or the 1.8T, do you have
Are you meaning to say that an aftermarket DV would be necessary to keep up
with the extra boost produced by chipping?
I was at my mechanic's only yesterday and he told me turbo lag - rather
noticeable on 1.8T's, could be reduced by using an aftermarket DV, do you
know how much science is in that statement? Maybe that's the one question
for your "gurus" :)
PS. Ever so grateful you recommended that little box to me!
If the car seems to be running normally without a MIL, check for boost
level with a pressure gauge. More than likely, the MAF has expired.
I have replaced the MAF on both TDI's I've serviced.
Same sypmtoms, runs fine, no MIL, no boost. The output under load can
be checked with the VAG.
For that matter, so can boost.
However, as there is still some slight surge in 5th gear at full throttle. I
suspect my MAF or DV could be on their way to paradise, too. Then, again
throttle body has not been flawless in pre '00's 1.8T engines.
After reading some Audiworld post, do those of you here think it wise to
install some aftermarket DV?
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