Phildrum

Hey everyone,

Curious if anyone can provide me some insight into this issue I have with my 2004 Audi A4 Avant, 1.8T, FWD, CVT with 144,000kms. I have searched these forums and Google a ton and while I can find people who have the same issue, they never seem to post what the issue is when they discover it (or they never find out!).

Rpms and vehicle lightly surge while under light to moderate acceleration or load. Does not happen over 2000 rpms, either if you stomp on the gas or are cruising over 2000 rpms, and is also barely noticeable when the engine is cold. This often seems to happen about every 3 seconds while driving, although it's not always that consistent. If giving the right amount of throttle, it feels like the car is hesitating to downshift and the vehicle will shutter momentarily.
I have cleaned the MAF sensor and Throttle body. Took it to a transmission shop with a fantastic record, explained that I thought it might be the torque converter. Let the vehicle there for the day, tech took it for a drive and said that he thought it was more engine related. My guess though is that they drove the car when it was cold, likely around the block a few times, and didn't actually experience what I was describing. Then took it to the number one performance Audi/VW shop in town and this time I took a tech for a test drive. Tech totally felt and saw everything and have it scheduled for them to check it out on May 5th. They suggested to crack open the transmission to check fluid levels (it isn't leaking) and then maybe do a flush and filter change. Just wanted to check and get your collaborative wisdom before I drop $500 for nothing. I've read a lot that if it's the torque converter that's failing that, even if it's replaced, usually the breakdown of the TC itself will eventually destroy the transmission. So, what's your opinion? Torque Converter? Possibly a vacuum leak? Maybe the PCV/pressure regulator valve/crankcase vent valve (whatever the heck it's actually called)?.

Thanks in advance!

Link to the video is here https://www.youtube.com/watch?v=rVaH...ature=youtu.be

Prospeeder

Well its CVT, so no converter. The surging is a sign the transmission is on its way out. These CVT transmissions are junk, and even bigger pieces of junk when they are not maintained properly, like fluid changes every 30k miles. You could try and change the fluid but i have doubts it will solve anything. 500$ is way to much, it shouldn't cost more than 300 bucks to change the cvt fluid. 6 quarts of fluid, 22$ a quart, and an hour and a half to swap the fluid.

Phildrum

Prospeeder, thanks for the reply. Yeah, sadly my Jetta GLI decided to completely die unexpectedly in the matter of a week so I was scrambling to find a new vehicle. I didn't realize the insane amount of problems that were tied to the CVT until after I bought it. The pressure of being out a car for my wife made me jump on another car when I should have done more research.

I cannot believe with the sheer number of forums I read that I did not know that the CVT does not have a torque converter. I searched a bit more and it sounds like the forward clutch is likely toast and needs to be upgraded to a seven-friction stack-up.

"To prevent a stalling condition when the transmission is placed in gear or when it comes to a stop in gear, a clutch inside the transmission must release. The VTlF and 01J CVTs release the forward or reverse clutch, while the Honda Civic CVT releases a start clutch in both Drive and Reverse. These clutches are pulsed on and off very frequently and are susceptible to failure. This can cause a variety of complaints, such as chatter on takeoff, sudden slipping or neutralizing conditions, unusual idle fluctuations or a loss of hill-hold function." (CVTs drivability problems).

That last sentence literally describes everything that I've been experiencing. So, my question is that if I replace the clutch stack-up and do the appropriate reflash (to change the pressure), what's the likelihood that this transmission will fail again?

Prospeeder

If you keep up the 30k fluid changes, it should last the rest of the life of the car with the upgraded internals with the extra packs.

Phildrum

Thanks Prospeeder.

I'm taking it to a transmission shop tomorrow to see what their diagnosis is. Apparently they have fixed a number of Audi CVT transmissions with great success rates. I spoke with the owner of the shop and he said there is a possibility it actually isn't the clutch and is another tranny issue. He said that to replace the clutch it'll run around $5000 and around $1800 if it's this other issue he mentioned (cannot remember what he said). Seriously hoping it's the second issue!

I'll post once I get the official diagnosis.

AndreSilva

Hey Phildrum!

Did you manage to fix it ?
I have an A6 C6 2006 with CVT and I have the exactly same kind of problems, in the morning with the car cold it almost never happens.
The mechanic told me I should make a full flush of the fluid for around 300 euros, but I`m afraid to do that, not fix it and still have the problem