2000 Passat V6 Engine Misfire + Check Engine light

Folks, I'm at wit's end with the following problem:

When the car was about two years old (and just a couple of months after
the 40K service), the check engine light began to turn on occasionally.
Eventually, I started to notice what seemed to be a misfiring /
sputtering of the engine at low RPMs (when first starting from a
traffic light or whenever i accelerated aggressively enough to make it
downshift). It would seem like it wanted to stall, but when the RPMs
got higher it would be fine. Felt a bit like when a spark plug is
mucked up... This problem only happened on long rides (longer than 45
minutes)

I took it to the dealership and they diagnosed it as a "random
misfire", which they allegedly fixed. Lo and behold on my next long
ride, the exact problem happened. A few months later (unfortunately,
it's a royal pain for me to spare the car for a day), I took it back.
This time they told me that there was a faulty temperature sensor that
was causing the car to inject the incorrect fuel mix (???). They
replaced the sensor and declared it fixed. The shuddering of the engine
stopped, but the car felt very sluggish for a couple of weeks, at which
time, the original problem came back (shuddering, engine light on...).

Before I take it back to the dealership so that they can try their
random theory of the month, I'd very much appreciate any insight that
any of you might have into the problem because I'm starting to feel
like I'm being taken for a ride by the dealer, who is either unable or
unwilling to really solve the problem.

On a related note, I am a bit intrigued by the whole story of the
ignition coil recall that VW had for 2001, 2 and 3 cars. I know that it
mostly applied to 1.8L engines but the description of the symptoms is
pretty compatible with what I'm experiencing...

Again, any thoughts and advice would be most welcome.

Regards,

Sergio.

Sergio,

I have a 1998 VR6 Jetta that has a tendency to occasionally misfire, at
which time the check engine light will come on if left untreated.. I
understand there is some history of coil-pack cracks that may lead to
this happening. Also, a new coil-pack might cost quite a bit.

What has been most effective for me is to spray WD-40 on the coil pack
and plug wires when this happens. The immediate cessation of the
misfire and eventual extinguishing of the check engine light are my
only proofs that this is an effective fix. I have been using this
occasional fix for over 80,000 Kms and am so satisfied with the result
that I keep a small can of WD-40 nestled under the hood, (not that I
have to do it very often!).

As the old saying goes, your mileage may vary, but I hope this works
for you if you choose to give it a try!

Fixing a random is a difficult problem for even the best VW techs out there
and may require more than just one day at the dealer. Might even need the
tech to drive the car for several days to get a grasp on the issue. You must
provide as much information as possible so the tech may rule out a lot of
ideas. But do provide info such as:

1- when-which you did
2- is it only when fuel is below a certain level in the tank
3-weather conditions
4-at what speed
5- up hills , down hills, left or right turns, etc

I once had a V6 Passat that would only miss on turns, which turned out to be
water in and around the cowl area. The cowl drains were plugged up and the
water got pulled into the vacuum brake booster... then on turns it got
pulled into the intake which caused a misfire and MIL would flash.



"Sergio" > wrote in message
oups.com...
> Folks, I'm at wit's end with the following problem:
>
> When the car was about two years old (and just a couple of months after
> the 40K service), the check engine light began to turn on occasionally.
> Eventually, I started to notice what seemed to be a misfiring /
> sputtering of the engine at low RPMs (when first starting from a
> traffic light or whenever i accelerated aggressively enough to make it
> downshift). It would seem like it wanted to stall, but when the RPMs
> got higher it would be fine. Felt a bit like when a spark plug is
> mucked up... This problem only happened on long rides (longer than 45
> minutes)
>
> I took it to the dealership and they diagnosed it as a "random
> misfire", which they allegedly fixed. Lo and behold on my next long
> ride, the exact problem happened. A few months later (unfortunately,
> it's a royal pain for me to spare the car for a day), I took it back.
> This time they told me that there was a faulty temperature sensor that
> was causing the car to inject the incorrect fuel mix (???). They
> replaced the sensor and declared it fixed. The shuddering of the engine
> stopped, but the car felt very sluggish for a couple of weeks, at which
> time, the original problem came back (shuddering, engine light on...).
>
> Before I take it back to the dealership so that they can try their
> random theory of the month, I'd very much appreciate any insight that
> any of you might have into the problem because I'm starting to feel
> like I'm being taken for a ride by the dealer, who is either unable or
> unwilling to really solve the problem.
>
> On a related note, I am a bit intrigued by the whole story of the
> ignition coil recall that VW had for 2001, 2 and 3 cars. I know that it
> mostly applied to 1.8L engines but the description of the symptoms is
> pretty compatible with what I'm experiencing...
>
> Again, any thoughts and advice would be most welcome.
>
> Regards,
>
> Sergio.
>

Thanks for the replies! I will be taking the car to the dealer next
week. At this point, the problem occurs pretty much all the time (car
is hot, cold, weather is wet, dry, fuel is empty or full)... Hopefully
they will come up with a good theory. Incidentally, if anybody out
there has a favorite VW dealer in the boston area for service, I'm all
ears!

Thanks again,

Sergio.