What does the hive know about the DSG (Don't Shift Good)?

In a relatively recent thread that I made, I was on the hunt for a non boring full size wagon. My goal was less than 15k, preferably less than 10k. 

Well, I ended up with a 2010 Passat, 2.0t, DSG, for 700$. No, it didn't run, and yes, it was very ugle, but it was complete, body was straight, interior was in very good shape, and even though I couldn't get it to turn over, I knew I could part it out for more if need be. 

Turns out, it didn't need much. Tires were the most expensive item, the rest were my usual add ons; better stereo, trailer hitch for the bikes, plus, fluid changes, etc. etc. Charged the battery, gave it a once over, and have been daily driving it since (month or so)

I'm just short of 3k into it, and it's an absolute pleasure to drive. I've not driven a VAG product in a while, and it is a very nice, comfortable highway crusher. Plenty of room for all of my kid's stuff, not perfect enough to fret too much about taking it out on mellow USFS roads or the spilled Goldfish crackers in the back seat. 

In all, I love it. Almost all of the time. 

But, this DSG voodoo box....this is new. 

I've changed the fluid and filter, using the proper procedure to check the fill level and using the recommended fluid (Liqui Moly). I have a VCDS, so I have done the adaptation as well after the fluid change. When the vehicle is warmed up, it's brilliant, smooth, but with firm solid shifts. 

When cold, dead cold, the start from a stop is absolutely abyssmal. It makes me feel like I just started to learn to drive a manual again. I have tried it with auto hold on, and off, manual mode in first, sport, all modes behave the same.

It is, in short, as if you just drop the clutch in a standard manual transmission vehicle. Yes, you're going to go forward, and yes, it is going to come with a big THUNK as everything snaps into movement. The transmission does nothing to feather it's way into motion, just immediately drops into motion. I've attempted several different tactics to prevent this, one of them is to slowly, very slowly add pressure to throttle pedal, "maybe I'll creep up on it" I think. Nope, very lightly pressing the pedal, it's: nothing, nothing, nothing, THUNK . At which point the throttle is barely depressed and the engine is barely ticking over past idle, but yes, why not just dump the clutch(es?) into gear? 

When the DSG is up to temperature, all issues go away almost entirely, besides the occasionally clack when the system downshifts. This is counter intuitive to most DSG issues, and I can't seem to sort it out. Or, most give up on the DSG once they reach a certain point.

My next play is to replace the N215 and N216 solenoids on the mechatronic unit, as during some deep diving, it sounds like this is exactly what they control. Cheaper than the entire mechatronic, so we'll see. 

Another possibility I could see is that the ECU is delaying throttle application when the engine is cold, and something is not playing well with how this is translating to the DSG. There aren't any codes present, but it's crossed my mind. 

Help me GRM, you're my only hope. 

(to answer the inevitable question, why DSG and not manual? SWMBO has no interest in driving a manual, so this is the compromise. I get to have a dirt bike and a 100 series LX470, so I'm okay with the sporty wagon even though it's sort of a slushbox but not really)

Nothing to add but to direct you to the VWvortex DSG Hive Mind.  I would expect your answer lies there.

https://www.vwvortex.com/forums/dsg-and-s-tronic-transmission-forum.988/

For anyone who found this thread who is having the same issue, and who is very very tired of searching like I was, here is what has worked for me: 

I replaced the N215 and N216 solenoids inside of the transmission, it has fixed the issue just short of when the transmission is dead cold and starting from a stop within the first few minutes. Even then, the engagement is solid, just need to be gentle on the throttle pedal or it engages a little rougher. The fluid I drained, that I put in less than a year ago, was very dark and I have new fluid on order. I used the fluid that I drained to refill the transmission, less than ideal, but none was available locally. I am hoping new fluid clears the cold start issue up. 

This is a relatively painless process that can be done with the transmission in the car (at least on my B6 Passat), and is only minimally messy. Be very careful with removing the mechatronic board and the screws associated with it. Thoroughly clean the area around the front trans pan before removing it, and take your time to not drop any grit or screws into the transmission. 

You can purchase the genuine Borg Warner solenoids: https://cobratransmission.com/vw-dsg-solenoid-variable-force-n215 

After removing the ones out of the transmission, you can feel and hear the difference in the solenoids, the old ones are rattle and are loose, the new ones are tight and the valve moves with a "thunk". My guess is the tolerances start to open up on the solenoids and they do not engage as strongly which caused the DSG controller to try and remedy the situation by pulling itself out of gear and trying again. Truthfully, I have no idea, but it seems logical. 

You can reuse the solenoid gasket/screen, but you can also purchase that separately if you need it. I don't know if you need to replace the pan gasket, I did not and it is working fine. 

If every thread you have read says "replace the mechatronic unit", this is likely the culprit. You could feasibly replace all of the solenoids/valves on the mechatronic unit if you wish, but I read somewhere that the 215/216 solenoids (I believe the main clutch solenoids) are the main ones that fail. I learned about this from here: https://www.evosoft.dk/tech.html

When refilling the fluid and cycling the gears, the difference is immediately noticeable. Once the adaptation was done, it was like an entirely different car backing out of the garage. Releasing the brake pedal, it backed up smoothly and without and harshness or gear confusion. I am able now to stand on the throttle from a dead stop with no worry of harsh engagement (rare that I do this, but testing). In normal driving it behaves seemlessly, gear changes are more crisp, and all in all the transmission feels more connected. 

If you are experiencing similar issues, I encourage you to try the solenoids. My plan was to "work my way in from the outside", eventually ending up with possibly replacing the clutches if need be, but I wanted to try everything I could without dropping this lump of a transmission if I could avoid it. 

Disclaimer:

This is probably not in the VW/Audi service manual. You can 100% destroy your mechatronic board (it is incredibly brittle) and/or destroy your transmission by getting junk in there (probably). You can destroy the wiring harness. You could be wasting your money. 

But you could also fix your car.​​​​​​​​

Great update!

I'd like to own a DSG car someday, but the older ones that I might actually be able to afford have always scared me off. It's good to know they're not a ticking time bomb. 

In reply to Pete Gossett (Forum Supporter) :

It's really a very nice transmission. I imagine the newer ones are even better, but the DQ250 box is still fantastic. It does all of the right things you want it to, just without a clutch pedal. I do miss a lot of the driver involvement that a manual offers, but I'm also able to hand my toddler snacks or give him a high five whenever he wants, so it's a trade off. Also my wife can drive it now (finally), if we wanted to hand off on long drives. It does still have it's quirks, I think that's mainly due to dated software, but if you plan ahead like you would with a manual, you'll be alright.

Like most older cars, most of the information you find is just a "replace the whole mechanism" move in this day and age of planned obsolescence, and it took what seemed like too much digging to find the Borg Warner part numbers, and if it was even possible. I'm glad I spent the time and took the chance despite the limited information online. 

The DSG in a new MK6 Golf R I drove was absolutely amazing.  It was full on supercar behavior but docile if you were.  I am also scared of them aging but it sounds like people have some good solutions to their woes.