mthorp

I am seeking some diagnostic help for an issue I've noticed in my new (to me) D2 S8. In general, it runs quite smooth (smoother than any other car I've owned), but there is a very steep hill right before my house and I've noticed that every time I start going up this hill I feel a slight stutter (not enough to rattle, just slight shaking). If I pull off the gas a bit the stutter stops and then I can accelerate again and it's mostly fine (occasionally it will stutter again towards the top of the hill and I pull off the gas again). I don't see this stutter anywhere else (I drove around today, including highways, to see if I could detect anything).

I'm new to working on cars (or diagnosing), so I guess I'm really asking for general pointers and things to try so I can gather more data on this and hopefully figure out what is causing it. Any ideas?

silverd2

May not be much help, but try to isolate what gear you are in when stutter occurs...more than 1 gear?
When it starts, switch to tip to determine the gear...plus observe if the stutter continues.

mthorp

It's in 3rd gear. I switched at the beginning of the hill and went the whole way up in 3rd gear, and the stutter came at the usual point in the hill.

I'm going to flush/refill the transmission fluid next week (needed to get done anyway) and see if there is any improvement.

silverd2

Flush? Debatable if beneficial in these transmissions, esp at high mileage.
But aside from that, I hope you intend to change the atf filter also. A fluid change without a filter change is more likely to further clog an old filter (breaking loose sediments with new atf detergents...going straight to old filter)...much more detrimental to a transmission that old atf, overworking the pump and lowering pressure. A flush does not clean a filter...it's designed not to let any contaminates pass through it.

tehA8PIMP

Try tellin us at what rpm it happens... my test is to go up hills in 5th doing 55mph+ and try to see how the tranny feels as it decides to drop down into 4th or then 3rd... somewhat a decent stress test, tells you what it can handle

mattsimis

A flush would allow him to confirm he has the correct amount of ATF fluid in it though. I had cutting out and limp mode on hills and was told the tranny should be rebuilt by a certain online expert. Told the same story to a local ZF rebuilder who said literally straight away the symptoms I described were of "chronic shortage of ATF fluid", not a rebuild type fix/problem.

The local guy was correct, I drained it to find the car only had 2.5litres in it! Im sure a rebuild would make it perfect, but Ive got pretty close to how it should be with a host of other small fixes without that $2k repair bill, for now at least!

silverd2

Agreed about avoiding a rebuild, any way I could. But a total flush (definition may vary?) is not required to achieve proper atf level...just a filter change (essential) and correct refill procedure. With a clean filter, a correctly operating trans and proper refill at proper temperature, the correct level is not a mysterious quest...it simply overflows, you plug it and go. If it works it works...if it doesn't, it's decision time

tozoM8

When you asked me you didn't tell me that you were 6qt low. The filter's pickup pipe is on the back end of the trans so when you go uphill the fluid level is higher by the pickup pipe. You also didn't mentioned that you had a major leak for a long time. 6qt is not a small spot on the garage floor. Just saying.....

mattsimis

I dont think you read the above or my first post at all before I got the default answer. Since you have outed yourself as the online person I spoke to, let me too be more direct:

- I just got the car (mere days of ownership), so there was no such history nicely laid out to you, me or the other guy. I stated I just picked up the car in my post so this shouldnt be surprising.
- I described the exact symptoms to you and someone else
- I got two answers, as it happened yours was "thats a lot of mileage, it will need a rebuild"... his was "after listening to the description, I think the fluid level is chronically low". You both had the same info to hand, I have no interest in misleading anyone Im asking for help, why would I?

If was able to "know" magically it was "6qt low" as you put it, then I would not be asking what I should do (duh).

silverd2

In defense of just good sense...not either party involved, I would put the owner of the car at fault here, the one with it in possession, the one who knows already what has been checked. I've read your original complaint. My wife knows how to check her fluids as preventive maintenance and to investigate symptoms...when she had a TC issue with her B5, the first thing she asked of me was to check her ATF level.

In your post you said you had run a Vagcom on the problem, was asking about valve body modifications, etc....this sounds like someone capable of looking at the gas gauge when your engine shuts off...trans anomalies = CHECK THE ATF LEVEL. I or anyone could easily have assumed that you had already done this, standard first check on ANY car auto trans, since the first time I ever drove a car.

YOU outed the poster yourself with a thinly veiled comment about a trans expert...who else could you mean? You were aching to make a public deal of this and you did.........Now take responsibility for your own actions and go change your panties!

https://www.audiworld.com/forums/sho...t=Transmission