Gahhruuba

Hello everyone, I am new to the Audi Community and I have a quick question..

I recently bought a 1999 Audi A8 4.2 Quattro, and seem to be having problems with the RPM's.
Every time I accelerate it will go up in RPMs and then for a quick half second it will drop down half a step or a full step in RPM's..

Example... I'm accelerating to 60, and it will drop from 2000 RPM to 1500 RPM while accelerating froma stop, and will consist until 60.. Even at a steady speed it still kind of sputters..

Anyone have any input/thought on this situation? Any input would be grateful!
The car looks dead sexy, it's just having a little trouble right now, might have a certified auto shop look at it within the week.

dreamhope

slipping clutch? changing gear?

Gahhruuba

It drops RPM through out the gears.
It does have a little bit of trouble changing gears it seems... Hopefully it isn't the transmission, but it's always a possibility.

silverd2

Could be the torque converter clutch releasing and engaging...clutch going or dedicated valve in valve body working intermittently. Need to read codes and look for a TCC stuck or performance problem.

Gahhruuba

I see, do you know about how much those run for replacement?
I will post up a video later on too try and actually show everyone what is happening.

I do not have access to any Code Scanners or anything, not particularly auto-savvy either.
Hoping that it's just a quick/easy fix.

Gahhruuba

UPDATE:

I have discovered that the slap shift and shifting manually up and down works perfectly fine.. It is just the Drive gear/option whatever that doesn't work correctly.
Still no video, phone doesn't record so will figure something out for that.

silverd2

I am no expert, by any stretch...especially with auto trans's.

If you're outside the USA, your 99 is probably the equivalent of a USA 2000 model...facelift with tiptronic shifter? If by "slap shift" you mean tiptronic side-gate shifter, then in tip mode the trans (trans computer) keeps the the torque converter clutch locked up most of the time. I've read many accounts of the rpm changes ("thumping") going away in manual/tip mode (if applicable).
I'm just theorizing from a semi-educated point of view, but your problem could be more of a control problem (computer), rather than a failing TCC...or possibly a problem with the TCC control valve (or solenoid that controls it).

Cost to replace the torque converter (if needed) could be high...a few hundred $'s for the part and requires dropping the trans to replace it...high labor cost there.

Determining the real problem involves some advanced knowledge testing.

TozoM8, a member here, is the real expert on trans problems...hopefully he will chime in here.

dreamhope

mine has a hesitation problem. it happens when going up a bumpy hill under light throttle. the solution I use is either to step on the accelerator (to convince the computer) or to use tiptronic.

Gahhruuba

Yeah, when I say "Slap-Shift" i'm talking about the TipTronic.

A couple hundred is waay better then a couple thousand for a new transmission, I just bought this car like 2 days ago lol.. Test drove perfectly fine.
And I am in the US, it is a 1999. Hopefully the guy you are talking about does put in a word or two here, would be awesome.

And to DreamHope, I stopped using the "D" gear mine has a whole bunch of hesitation while driving in D.. Flawlessly working with the Tip-Tronic

dreamhope

Just on a hunch, I agree with silverd2 in that your problem is probably with the torque converter, because it happens all the time in D. I can only think of one clutch that's engaged throughout D.

My problem is most likely with the front suspension (control arm on the passenger side that may not be 100%) that causes mixed feedback to the transmission on bumpy ascends (which is not uncommon in France, and during which it's hard to maintain a steady throttle position; cruise control also helps with this problem). The hesitation is alternate up-down shifting.

Before changing the torque converter, however, I would check the control unit first. If the transmission works fine in Tiptronic, I tend to believe it's an electrical problem.