Oh boy.

Been having problems with the Automatic ZF Tiptronic trans in my 1.8T. Up-shifting is generally slow, and the tach is ALL over the place. There just doesn't seem to be a logical up-shift pattern/procedure. Most often car seems to briefly go into neutral (engine revs) when shifting, and often seems to miss shift points in the rev range, climbing 400-500 rpm over when it should be attemping to upshift before even doing so. 2nd to 3rd seems a real problem section. Fluid had not been changed throughout the 95k mile lifetime of the vehicle (to the best of my knowledge), so I thought that it may have been an issue of low/degraded ATF. Went through the hassle of a fluid drain and filter change, and there doesn't seem to have been much of an improvement. Ugh. I also notice a significant amount of vibration from below the floorboards after performing the atf fluid and filter change - specifically when it moves into 4th? Also, the transmission seemed reluctant to shift to 5th at all. The problems are pretty similar in both full automatic and tiptronic modes. Haven't really had any problems with downshifting so far. It's difficult to tell, but the symptoms above seem to rise/worsen as the car gets hot.

Any ideas? I may run a solvent cleaner in with the transmission fluid such as Seafoam trans tune, which I've heard can work.

What sort of issue do these symptoms suggest? Something to do with the shift solenoids failing? A bad TCM? Faulty MAF sensor? Maybe a clogged valve body? I'm stumped, so any information/diagnosis would be helpful.

Thanks for the time.

 

When you changed the filter and ATF, what kind of residue was in the pan and on the magnets? I went through something like this on a 1.8T Jetta (JATCO trans), untimely was futile because there were worn-out clutches. However, thinking positively, I'd start with the electrical connectors, at the TCM, ECU, and both connectors at the front of the trans, using a spray contact cleaner. If you have a VAG-COM, watch the solenoid commands as you shift through the gears, preferably with the car on stands and running. If those look stable, and no fault codes, then maybe it's time to pull the pan again. I saw a tech article once for an A8 ATF change, the guy solved a shifting problem by pulling the solenoids and cleaning small strainer screens fitted above the valves.

 

I really should have paid closer attention to the residue at the bottom of the pan, as I know this is where clutch material gathers. All I can say is that it was a blackish sludgy goo, but can't tell how much. I know some sludge in the bottom of the pan is normal.

The transmission, however, is not slipping while already in gear, but seems rather to be doing so between gears. Any trans code would set off a CEL, correct? No CEL is present as of now.

What is the general opinion on running a cleaner/dryer through the trans? I know AW member jschick has used it, supposedly to good effect, and if there is any way that running some of this through the system would clean up a valve body/unstick solenoids, I would love to just try that.

Cleaning all the electrical contacts seems like a decent place to start. Don't have VAG-COM; should really invest in it... May take the car to a local mechanic to have him run diagnostics on the solenoids, although I'm sure that'll cost me a bundle -.-

Any idea if there is a special procedure for removing the solenoids? It seems like a job that wouldn't be exactly cut and dry...

What of the vibration? What might be causing this?

Praying to God no internal failure... 'cause then I'm screwed.

Thanks for the input.

 

Update:

Went for a lengthier test drive tonight to try to get a bit more information about symptoms. Whether the engine/trans is cold or hot seems to make very little difference in symptoms exhibited.

When shifting from from 2nd to 3rd, and 3rd to 4th, the revs jump slightly, then the shift occurs (basically normally, not too hard). When shifting in tiptronic mode, I found that symptoms changed slightly. 2nd to 3rd stayed generally the same, with revs jumping, then shifting. 3rd to 4th seemed to happen more readily, as trans was somewhat reluctant to even attempt 3rd to 4th when in auto shift setting.

What I really want to narrow down is if this will be something that I can fix, such as a faulty/clogged solenoid(s), or something I can't, like worn clutch packs. Would worn clutches be showing the symptoms listed?

As noted before, downshifts are seamless, auto and tip.

Give me some good news guys.

 

this is a very common symptom of the trans fluid just not being changes soon enough or just low on fluid. and since Audi's are my hobby this would be my favorite car to buy! I have bought 5 just like this in the last 2 years, so far all have been fixed. generally just a good fluid change takes care of it, if not I have also had very good Luck with Seafoam trans tune on my last A4 that really has issues with going to neutral then slamming into gear. If the car does not slip then yes it is your solenoids sticking or lack of oil pressure internally. So we need to clean that out to get the fluid flowing! my next step would be add the trans tune and drive for 100 miles if that takes care of it, change fluid again and you should be good, if not you will need to get to the screens on each solenoid and clean them.

 

Ok, yea I was thinking it may be along those lines as well.

Just got a code thrown by the diagnostics system, so going to read that as soon as possible. I assume that it may be something like a shift solenoid mechanical fault.

Thanks for the input.