ezatnova

I've noticed this problem for about a year now since I got my tune but I've finally had it and was curious if anyone else has seen or experienced this.

The issue is that, at moderate throttle but NOT at 100% (so, say 50-80%...enough to make the car go at least to 5k rpm above before shifting), I will get jerky stuttering and hesitation at about 2 or 3 times.

For example, if I'm on a highway doing 60 and want to pass someone, and give the gas enough of a push to shift down to third and accelerate quickly (again, not flooring it), when third gear hits 5k rpm, the car will start bucking a few times. Similarly, if I am driving on a back road and put the car into S2 and moderately accelerate, again at 5k rpm and above, the car will buck between one and a three times.

It is definitely noticeable physically and audibly (I've had passengers ask me what the heck is wrong with my car on several occasions). It is also definitely not ESC/TCS because, again, this does not happen at 100% throttle, only partial. Also, no ESC light and this is happening at 70-80 mph on the highway example, above.

Here is a video link where you can see it happening in my S2 example I mentioned. It's actually easiest to hear it, but you can also notice the needle slow down twice if you watch very closely. You will hear two hesitations, one right before the gauge hits 5k and one right before 5.5k. You can also notice my phone lurching as it happens since acceleration is cutting out.

FYI I have started talking to the tuner last night, and he will be getting back to me, but I figured I'd see if this is an isolated incident in the meantime.

http://www.youtube.com/watch?v=TTPKX...ature=youtu.be

cls55

Thats 5 seconds,not enough to see anything.

Merc63

I never seen any stutter or heard on the vid.

What air filters are you running? put the stock ones back in.

ezatnova

How is it not enough time? It only takes a few seconds to rev from 2k to 6k. The hesitation can clearly be heard twice. Also the whole car lurches. Can you not see the camera move twice?

ezatnova

Stock filters. Had the carbons out but put them back in this morning to eliminate that variable. Will test this afternoon.

cls55

I looked at it 5 times,could not determine anything.sory

ezatnova

You might have your speakers too low. You won't see it by just looking at the needle. Watch the whole camera move, and listen when the needle hits 5k.

ozsn

My car used to do this heistation/surge and then I got a check engine light that would go on and off. I took it to the dealer at it turned out to be a intake manifold gasket leak (you might also want to have them check the purge valve). The error codes that would come up were P0451 and P2187. My car has a Eurocharged tune and I am running BMC filters, but kept the charcoal ones in because after I took them out the check engine light came on about 30 miles later.

Sincity

I had a "stutter" or what I would describe as a slow shift (which causes my head to buck a little) when it shifts about 4500-5000 RPM and about a 50%-80% pedal input as you described. Did not have the problem when I fully depressed the pedal. Clld the tuner and new tune does not have that effect. Tuner did ask me to check the MAFs since I had K&Ns but that did not turn out to be the issue. I did not have any codes/CEL. Sounds like you have the same issue I had.

What tune are you running?

PS-Agree with CLS55, hard to see in video especially with the glare.

ezatnova

The issue is not when it shifts. This is all in-gear. The important part of the video is not the dashboard, it is the sound and the movement of the entire camera.

Sincity

It just drops the RPM like a cut-out without shifting?

ezatnova

Not quite a drop. Just a hiccup. Like if you were to flutter the gas pedal like a wawa guitar pedal. Press-lift-press-lift. It happy so fast that RPM's don't decline, they just stop rising for the time that you can hear the blurbs in that video (happens twice both within the 0:03 second of the vid). You are correct that it has nothing to do with shifting.

ezatnova

Brief update that putting the carbons back in did not help. Removing the tune did. Car is butter smooth in stock form. Very frustrating.

I am talking with the tuner now and got a new file to try, but I have my doubts that anything will work. Feel like I need in-person tuning help for this issue, and unfortunately the Philly area doesn't seem to get many frequent visits from the flash loader tuner guys.

Sincity

I agree very frustrating. I lived with my old tune that way for a year before I decided to get a new file. At least you know it's not the car.

Fung63

interesting. what tune did you have?

i found after my tune, the car shifts flawlessly and can feel power throughout the gears

ezatnova

Who/what happened with the file that worked? I've Ben through about 10 tweaked files between OE and Eurocharged and nothing has hit the nail on the head yet.

Feel free to PM if you'd rather.

ezatnova

Never had any problems with shifting.

Issue has occurred with both OE and Eurocharged files, so whatever they do similarly annoys my car.

Sincity

Kleemann. Cory has been very helpful in getting it resolved (not saying that Jeremy and Jerry not doing the same since they are both responsive). His programmer looked at the file several times and didn't see anything different (canned tune) and didn't know why it would cause my issues. The new file I have is reportedly not as powerful though I haven't been on a dyno. Cory never did tell me what parameters they changed. I'm running K2.

D.T.SFK

I have this exact same problem as you ezatnova!!! However, my car is currently running the stock tune with K&N intakes and charcoal delete. It's been happening for a few months now, and within these few months I have taken it to the dealer, and the problem is still present. The dealer had changed by purge valve and resealed my leaking intake manifold but the problem persists. I'm glad you found your solution which was to change the tune back to stock, but I am on a stock tune, wonder what causes these hesitations?

ezatnova

I assume you tried stock filters and putting the carbons back?

Merc63

I'm beginning to think these cars are very pick with the MAF reading. Try your stock filters.

LAMB09

My car did something similar I think to what you describe after I got my tune a while back. I did a tcu reset took the problem away. Here is the link on the steps, same steps for both pre facelift and facelift.

https://mbworld.org/forums/c63-amg-w...tcu-reset.html