Auto tranny problem

[rob hod]

  I think Ameer raises two good points here, and I'm with him in saying that
hesitation is unlikely to be trans. related.

I'd add that your original post implies that at a standstill your car wants
to creep forwards. This is normal but only to a small degree. E.g. my auto
idles at 800rpm. On level ground it will creep forwards very very slowly if
I dont have the brakes on.

 IF your car wants to do more than this then either your idle speed is too
high or there is indeed a problem with the transmission.

   So to cut to the chase, what is your idle speed?

    Also I'll add that driveline vibration is often caused by worn CV
joints, including the inner ones, - in my case I had a rumbling vibration
which only occured at full throttle with revs under 4000, although my joints
appeared sound the problems disappeared when I replaced the inner CV on one
side


    Cheers,

  PS I have an older 3 speeder on my 88 100, and it has been totally
reliable all the while I've owned it (3.5 yrs) so don't believe people who
say that they are all bad.

rob
----- Original Message ----- > Message: 3
> Date: Fri, 13 Feb 2004 17:28:30 -0500
> From: Ameer Antar <antar at comcast.net>
> Subject: Re: Auto tranny problem
> To: Doug Yoder <yoderw at msoe.edu>
> Cc: Quattro List <quattro at audifans.com>
> Message-ID: <20040213222827.E83076F447 at audifans.com>
> Content-Type: text/plain; format=flowed; charset="iso-8859-1"
>
> It sounds like you have 2 problems here:
>
> 1. car wants to go when you brake
> 2. engine hesitates when you accelerate
>
> As for #1, my Chevy Lumina also does something similar, especially after
taking it up to 85 or so and then slowing down at an exit traffic light. I'm
not 100% sure, but a friend w/ the same car said it was the tranny.
Basically, the tranny wasn't down-shifting, so even though the car was only
going 10-15 mph, it was stuck in 2nd gear. Since the engine has a minimum
idle speed, the idle speed controller fights w/ the brakes, b/c idle speed
in 2nd gear is more than 10-15mph. Mine has a similar feel, and it also
feels like it will stall (and does sometimes). I also had this problem on a
Pontiac 6000 which had a torque converter lockup system. The system
eventually had problems disengaging and would stall the engine all the time.
The solution on that was to just unplug the lockup system. Unfortunately on
more modern trannies, I think the solution is either a rebuild or
replacement (probly the cheaper method).
>
> For #2, this seems like the engine is becoming lean when accelerating. If
the engine gets a lean mixture it will hesitate and feel like you lost power
for a second. The ECU can probably compensate, but there is a limit and may
take a while to respond. I highly suspect a vacuum leak somewhere in the
intake system. Leaks are common on these cars and cause lots of trouble. You
should remove and check every hose (esp. the big ones) b/c the problem
probly won't stare at you in the face. Cracks are often on the underside or
near the clamps. Also there are things like oil cap and valve cover leaks
that can cause trouble too. This place is a good place to start running down
the checklist:
>
> http://www.sjmautotechnik.com/vac.html
> http://www.sjmautotechnik.com/trouble.html
>
> Hope this can help solve at least one of the problems cheaply.. good luck.
>
> -Ameer
>
> ---Original Message---
> Date: Fri, 13 Feb 2004 11:07:21 -0500
> From: Doug Yoder <yoderw at msoe.edu>
> Subject: Auto tranny problem
> To: quattro at audifans.com
> Message-ID: <402CF639.30801 at msoe.edu>
> Content-Type: text/plain; charset=us-ascii; format=flowed
>
> Hi everyone-
>
> My '91 100 (non-q) has some driveability issues which I think are
> related to the transmission, but I'd like to get some other opinions too.
:)
> Car drives OK most of the time, but when I am accelerating in low RPM
> (under 2500 or so), the car shakes a lot.  The happens usually in higher
> gears.  When braking and while stopped at a light, the car "wants to
> keep going" (thats the best way to say it, I think).  IE, when braking
> it feels almost like you're driving with one foot on each pedal.  Also,
> the car hesitates a little when you press on the accelerator (worse when
> you stomp the pedal, still there a little when you are gentle).
> To me, this sounds like the torque converter is slipping.  Any other
> ideas?  I have no experience with working on transmissions... is the
> torque converter something that can be fixed/replaced easily?  Will I
> need a new/used tranny?  If the torque converter is replaced is it worth
> doing the tranny at the same time (ie, you're in there anyway...)?
>
> Thanks,
> -Doug