Hi guys,

I know there's already a thread on the first page with another MCT issue, but I didn't want to post in there in case our issues are different. Anyways, I just started running into transmission issues this morning on the way to work. I'll try to post as much information as I can possibly think of...

Breakdown:
2013 C63 Base w/ 60,XXX
Transmission service done at 45,XXX by Bergen Imports
Mods:
ROW airbox
aFe filters
2nd cat delete
*Has never been tuned*

Things to note:
I installed the ROW boxes on 12/10, but never drove it until this morning.
I took the car out in the snow for about 2-3 min on 12/9. Went down the end of the street (with traction control off), spun the tires a bit here and there, then parked it back inside. The only thing I can think of is that something happened during the few minutes I was in the snow. I literally made a left out of the garage, whipped it back and forth a few times down to the end of the block, pulled a u-turn, then slowly drove right back to the garage. It's hard for me to say I noticed anything when I was driving the car back to the garage... It's possible that the trans was slipping then, but with all the snow and no traction, I never realized it.

This morning, after I noticed something was wrong, I reset the trans adaptations... I drove the car a bit spiritedly to try and get the trans to shift a bit faster after the learning process. It made it a little better, but lower gear changes (specifically 2-3) take about 9 years to finally engage. It feels like the computer is trying control it... And is doing a very poor job of doing so... Because, if I mash on the gas, gear changes are normal and quick. But, with 1/4 - 1/2 throttle, the car slips in the lower gears. Even if I go more than 1/2 throttle, the trans won't slip. It'll go into each gear pretty normally. In S or S+ mode, the car shifts normally-ish... But I can tell there's still a slight lag or delay when shifting in the lower gears.

What do you guys think?

Below is a link to a video I just posted...

 

So, I went back out to try and get some more video. I put the car in M and it seems like each gear is slipping when it tries to engage. Is it possible that I fried the clutch packs? Do you think this might be software or a mechanical issue?

The link to the other video:

https://www.youtube.com/watch?v=-D9e...ature=youtu.be

 

If I drive feathering the throttle it holds revs like that

 

Hmm.. That's interesting. I've had the car for a little under a year and it's always shifted a lot quicker than what's in the video

 

Watching from the phone right now but the first vid looks fine to me....even though blurry.

Second vid of m mode does not appear normal to me. I'm seeing 500+ rpms after u hear the paddle click

A select few knowledgeable people around here have said those row boxes and afe filters can cause weird transmission issues

Eliminate the variables. Put oem boxes and filters on the car and go diagnose

 

He's driving the car in c mode and fethering the shifts.the car in comfort mode slips the clutches to give the smoothest shifts.

Try this in m mode and more gas or faster pedal input and make a video.

The car adapts to the way you drive it and if you drive it like a grandmother then it will shift like one too lol.

My car will slip 3rd gear but that is going wot and banging the Rev limit to 7500 .not at 1500 rpms with zero load on the clutches

 

The ROW boxes can cause trans issues? I'm not sure how that works lol But it's a simple switch so I'll swap them back tomorrow and see if that changes anything. Thanks for the input

 

I made a 2nd video, it's the 2nd post in the thread. I did it in M mode. You can see there's a decent delay from when I click the paddle, to when it decides to shift, to when it actually grabs the next gear. The delay from the computer telling it to shift will always suck... But the time it's taking to engage the next gear is pretty long.

I see what you're trying to say about feathering the throttle, but I don't think this is normal... The car NEVER shifted this slowly before. It's a noticeable change. Do other 63s shift that way in C mode? I've only driven one C63 so my sample size is a bit small lol

 

Shifting manually in C mode will shift smoothly and slip the clutches but in one fluid motion. You car seems to shift in two-steps. I've seen that on car with a stage 3 SC shifting 4-5 WOT... Definitively not the same situation here.

Flush the trans fluid again. You only get 60-70% when you change it. If you changed it for the first time at 45,xxx and you're now at 60,xxx. Its worth a shot to flush it again.

 

Welp... I figured it out thanks to you guys lol. I was gonna put the stock air boxes back on and I noticed the filter on the drivers side wasn't seated properly and the rubber seal was pinched, leaking air past the MAF. Re-seated the filter, made sure everything was snug..... Car runs perfectly!! Thanks again for the suggestions guys.

Weird how the car responded by shifting slowly...

 

Couldnt calculate the proper loads... Makes sense. Glad you sorted it out.

 

So I just got a set of ROW air boxes, and they came with aFe filters. Just to clarify, these are plug and play, or do i need to do some type of reset?

 

They work perfectly fine for me. Haven't gotten a chance to hook back up my OBD2 scanner to check fuel trims and whatnot. But, from what I'm feeling, they're great lol

 

Thanks dude and thanks for your help earlier on the thread