Having some issues with my tiptronic - only in second gear it seems, and only in Auto mode. It does a little stutter/shudder right at 2,000 RPM. Fine before and after, and fine if it is in manual mode.

Wondering what the first things are that I should check.

Thanks in Advance.

 

how many miles? Any mods? Might not be the tranny. Any other symptoms?

 

Thanks BlackHorse-

65,000 miles (had 63,700 when I got it 5 months ago).

Mods - ECU Flash - by UMW. Everything else is bone stock.

Recently serviced - 1000 miles ago as well.

I wondered if it might be something else as well. It feels like a stutter in the throttle, but makes a little bit of noise as well. Could it be low transmission fluid? How/where do I check this?

 

There is no dipstick, so to speak. You just replace the fluid. You have some miles on her. What is the noise? Could be a sign of a clutch pack going south.

 

It's not a noise so much. It does the sound and feel that you get when an idle drops below 700 rpm, or when the car stalls when you're first learning to drive a clutch. That is the feeling, like a hitch. 2nd gear doesn't do it if I shift out of first at above 3500 RPM (thereby skipping the 2,000 rpm range in 2nd gear).

 

I'll bet that you are on your way to a tranny rebuild. If you decide to rebuild, please call Mark D'agostin at Mercedes Benz of Eldorado Hills. The guy is great and does quick work. I'll PM you the number.

 

Does the engine speed raise (flair) before engaging 2nd? Once it engages does it bang or jerk into 2nd. Was the fluid cloudy? You could be experiencing torque converter lockup during the 1-2 shift as well. I suppose someone in the Sacramento area needs to let me drive their Turbo Tip to get a feel for Porsche trans shift programs. I might be more help in diagnosing then.
BlackHorse- I was thinking of emailing you today but got too busy, You get that thing in yet?

Mark

 

Hey Mark. No , not yet, Steve was hospitalized on monday with a strange but bad case of vertigo. He has been out since. So, it just sits and waits until he can be back to work. I'll keep you posted.

 

I feel for Steve. I suffer from the same malady. Thats why I stay in a straight line!

 

Sorry for thread jacking but the engine flair sounds exactly like what I am experiencing when I'm in M mode and braking from 2nd to a stop. Almost sound like someone is heel and toeing to 1st. Does it indicate any problem?

 

No it doesn't flair, just sort of lugs a little bit, almost like a car lugs when you're first learning to drive a manual.

Haven't looked at the fluid. How would I go about checking that??

 

It would only be an issue under acceleration, where the TCU commands a shift, but it takes too long to apply the clutch pack. As a result, the engine rpm will increase under the lack of load. This is not and issue while coming to a stop.

TT: the lugging sounds like a M-B C32 AMG shift pattern- normal. It also is the sounds like when trans fluid is contaminated with coolant. This was a common problem on 02-03 C and E classes with faulty radiators/trans coolers. The coolant first attacks the torque converter so that it basically does a slip, slip, sliiiip,, GRAB! Just like a newby learning to drive a clutch. Your car, I'm sure, shares none of those faulty parts, but it does have a ATF/coolant cooler. I have seen TCU adaption fix this issue on more rare occasions as well but I'm not sure how that works in cars w/o a star on the hood. If the fluid is cloudy, it may indicate contamination. How to check that? not sure, I've only had them on the bench. To drain is obvious, to fill, well thats another story
HTH