View Full Version : 2002 Jetta 1.8T 5 Speed Tiptronic Questions

01-10-2010, 11:26 AM
I posted this on Vortex also, but I thought you guys might have some ideas.

I bought the car because it was suppose to have a bad trans. I found out that the transmission was leaking fluid all over the ground and it ended up being the pump housing bushing. I replaced the bushing and seals and put everything back together. I've rebuilt plenty of manual transmissions, but this is the first auto I've worked on.

The car now slips from a stop, but appears to shift fine from higher speeds. When I try to check the fluid with a VAGCOM it just dumps fluid out of the check valve and I've let up to 2 quarts out and when I check and if I drive it after it slips more. Right now I have approximately 5 quarts of VW ATF in the trans since I put everything together and I'm not sure how much more I should add or what else could cause this issue.

I was told that the transmission is stock and when I got everything apart I noticed that the trans is an EYP and the build sticker in the trunk says it should have an EYN. Could it be possible they changed the trans in the past and the TCM was not changed and that is causing the issue?

I plan to add another half bottle of fluid and drive the car more to see if anything improves. I have 65 miles on the car since everything was put back together. I also have considered doing a filter change to see if that cures the issues.

01-10-2010, 11:46 AM
the filter prolly wouldnt hurt to change....

01-10-2010, 12:03 PM
That's about the only other option I think I have at this point. I put a few more miles on it and it's still not throwing any codes.

01-10-2010, 03:31 PM
Quoted from here (http://forums.fourtitude.com/zerothread?id=1379858&postid=63002154)

"A.T., 1.8L (turbo gas), 5 spd, trans code "EYN"
A.T., 1.8L (turbo gas), 5 spd, trans code "EYP" (almost all MKIV 5sp Tips)"

Perhaps the EYN transmissions had a short run for a reason, and the EYP, likely the improved version, fixes those problems? I'm going to agree with you here and say that either the TCM or the maybe even the ECU may need to be replaced so the car knows what tranny is has...

01-10-2010, 03:56 PM
Upon further investigation, I found this (http://forums.vwvortex.com/zerothread?id=4188370&page=1:)

Does that sound like your problem? Apparently the N92 valve takes care of shift changes up to 3rd; after 3rd it's a different solenoid and the car should shift fine...

01-10-2010, 04:26 PM
And solenoid replacement how-to here (http://forums.vwvortex.com/zerothread?id=1521077)

01-10-2010, 04:48 PM
Thanks lite. I've read those threads also. As of right now I don't think its a tcm or ecu issue since its not throwing codes and its able to read the trans fine and is throwing no codes. I hate auto transmissions:mad:

01-10-2010, 07:26 PM
u try resetting the ecu, or just disconnecting the battery for an hour?

it has helped in the past when i flushed transmissions that had air in the system, the transmission adjusts the shift parameters with the air pockets in the trans and causes hard shifts... but even after the trans was full it would still do it. reset the computer it was all good.

01-10-2010, 10:27 PM
Yeah the battery was out the whole time I was doing the trans and I have reset everything with vagcom and I am not throwing any codes. I'm making her drive it to and from work for a couple days and just take it easy on it and see what happens. It's only a 5 mile drive and I have AAA, so I guess I'll see what happens.

01-12-2010, 11:22 AM
Still having issues with the trans slipping. I checked it per the bentley instructions last night and let out about a liter of fluid and it seems to be about the same. Still no codes and about 200 miles on the trans at this point. I'm not sure if the clutches or torque converter were damaged due to low fluid, but I would assume either of those would cause a code to be thrown and that I would see a lot more metal in the fluid when I check it. I'm at a loss right now of what else I can try or do to diagnose the issue.

01-12-2010, 11:27 AM
maybe a different brand of fluid? what type are you using right now?


01-12-2010, 11:35 AM
Expensive as hell VW fluid. I'm tempted to do another change using the Mobil 1 stuff all the guys on vortex talk about.

01-12-2010, 01:10 PM
It still seems exactly like a faulty N92 valve, which would explain the absence of fault codes. It's reported as a mechanical failure in the valve, so there's no signal sent to the ECU telling you it's not opening properly...

Unfortunately, I think it has to be pressure tested to determine fault, and you have to drain the fluid and remove the cover on the side of the tranny to get it out, but at least you don't have to remove the whole tranny...

I wish I could physically help you on this one. Other than the auto tranny I put in my roommate's Honda, I don't have a lot of hands-on experience with autos either. :( Keep us posted!

01-12-2010, 04:28 PM
Looks like I'll be having fun testing solenoids this weekend. I knew I should have never got a mkiv.

01-12-2010, 08:06 PM
time for some lucas trans. additive.

01-13-2010, 10:10 AM
Already put a bottle in:mad:

01-18-2010, 12:17 PM
Well I got busy with about 8 other projects last week and this weekend and haven't had a chance to test anything, but it's high 40's down here and the problem is getting worse. Based on what she says it's doing I think I'm going to just pull the trans and change the torque converter and be done with it. If that doesn't fix my issue I have no clue what I'm going to do.