Ever since owning my 1990 Carbiolet, I noticed that
if I down-shift from 3 to 2 to slow the car down, the
car backfires once, rather loudly. It only seems to
backfire when the car is warmed and the speed change
(around 30MPH in 3rd) is enough to cause the engine to
rev to 3000 RPMs in 2nd gear.
Does anyone know the cause of this? I am NOT too
worried by it, just want to understand why? Could it
be a problem to worry about?
Thanx!
Pete M.
pet…@bnr.ca
In article <434n76$…@brtph500.bnr.ca> pet…@bnr.ca (Pete Morrissette P840) writes:
> Ever since owning my 1990 Carbiolet, I noticed that
> if I down-shift from 3 to 2 to slow the car down, the
> car backfires once, rather loudly. It only seems to
> backfire when the car is warmed and the speed change
> (around 30MPH in 3rd) is enough to cause the engine to
> rev to 3000 RPMs in 2nd gear.
> Does anyone know the cause of this? I am NOT too
> worried by it, just want to understand why? Could it
> be a problem to worry about?
AFAIK, it’s not at all good for the catalytic converter.
Others may have more detailed knowledge.
—
Scott Ashdown
Engineer, MPR Teltech Ltd.
Burnaby, British Columbia, Canada.
ashd…@mprgate.mpr.ca
In a word, it turned out *wonderfully*.
Of course, there’s more to it than that. People having bought or
planning to buy this car or similar models may find my experiences
interesting.
Now that it’s sorted out, I wouldn’t have anything else (in today’s
market in my price range, of course).
Minor problems:
1) GTI floormats are *very* hard to come by. I’m on a list at my
dealer, and have bought a very cheap set for the time being.
2) Cracked passenger side sunvisor clip at delivery, but missed
during PDI. Seems to be a problem on nearly every new Golf & Jetta.
Fixed.
3) Bit of noise from my doors when going over bumpy roads. Not very
bothersome, not fixed as yet, though my dealer has tried.
4) Car had been machine washed a few times prior to purchase – there
are some minor scratches in the clearcoat. If you don’t know what
clearcoat is, don’t worry about it.
Major problems:
1) Engine warning light coming on under load, but car feels excellent.
The cause turned out to be a broken wire to one of the knock
sensors. The dealer tried three times to fix this, third time was
the charm (mainly because I was able to give them a method to
replicate the problem – if you’re having a similar problem, mail
me for details). The broken wire meant nothing showed up in the
computer – very difficult to diagnose, I suppose.
2) Engine roughness, especially in third gear, under load, between
2400-3100rpm. My first thought was motor mounts. I *took a
technician for a ride* to make sure he knew what I was talking
about. Problem turned out to be a "misaligned" motor mount. Car
is now as smooth as glass. (NOTE: My girlfriend picked up the car,
so I didn’t get a chance to ask them about what they did to the CV
joints, as the rough work order mentions something about the inner
ones – this could be some sort of recall/TSB – I’ll post when they
mail the offical work order to me.)
3) I got a nail in my rear passenger tire, and guess what, VW doesn’t
throw a tire warranty in (they did on my father’s ’89 Jetta), and
they don’t mention one either! Get one. It’s the cost of a single
speed patch (never, ever plug a tire, get it *patched*), and is
a lifesaver in the case of sidewall damage.
–
Scott Ashdown
Engineer, MPR Teltech Ltd.
Burnaby, British Columbia, Canada.
ashd…@mprgate.mpr.ca
>>3) Bit of noise from my doors when going over bumpy roads. Not very
bothersome, not fixed as yet, though my dealer has tried.
I took my 94 Jetta in for dash "noise work" and while they were at it they
ordered a seal kit for my door panels. Check it out if your A3 is making
noise fromt he door panels. I also think the speaker boxes actually need
to be removed and glued or siliconed together so they won’t rattle.
4) Car had been machine washed a few times prior to purchase – there
are some minor scratches in the clearcoat. If you don’t know what
clearcoat is, don’t worry about it.
Try Meguire’s clearcoat scrub. It took out things I thought were much
deeper scratches. It turned out they were nothing.