ptirado961

Ok... This may not solve every C32 tranny/torque converter jerk issue between 1500-2000 RPM, but it did (I swear) for me. I have had my 2002 C32 since 2005. The Tranny Jerk has always been there, but kind of came and went now that I really think about it. I took it to the dealer (no luck). Had the transmission fluid and Filter changed to Redline Synthetic (no luck). Recently, I have been trying to save some green backs by going to the cheapest gas dealers I find. It was kind of a game with the kids to find a gas station advertising the cheapest gas. I always filled up with 93 octane, so I didn't think it would make a difference. I was Very, Very wrong... I started to notice recently that my engine was getting more jerky than normal at the 1500-2000 RPM band, and also noticed a rough idle, and unsettling highway vibrations. I was all set to order new plugs, and/or have it serviced by the dealer to see what the problem was, when I noticed I was due for a fill up.
Well, I decided to go to Exxon (not the cheapest) and fill up on 93 Octane. I bought a bottle of Fuel Injector Cleaner and poured that in the tank before I filled up. When I started the car, I immediately noticed it was smoother. After a few minutes of driving, I couldn't believe what I "Wasn't Feeling!!!" Smooth as silk engine, and ABSOLUTELY NO JERK Whatsoever!!! I was so stunned.
My Theory, is that the "Tranny Jerk" isn't tranny related at all. My Theory is that it is detonation or ping caused by an incorrect computer aided fuel/air mixture between 1500-2000 RPM. Mybe the knock sensor is sensing a ping or detonation and retards spark or adjusts something that creates the jerk, but I am now convinced it is most definitely NOT tranny related.

The other fact leading me in this direction, is that some people have been able to temprarily eliviate the jerk symptoms by performing the throttle position reset. hmmmmm? Seems fuel related there too...

I see a Myth Busters experiment in the works.

alkrstev

That is amazing, so you got a smoother running engine and smoother shifting transmission out of it. One question though, before you added the fuel injector cleaner, do you have to fill your tank all the way???

alkrstev

And another question, what was the fuel injector cleaner brand and how much did it cost? Thanks.

evilsaint

I think there was a pretty good deal of research done that proved the tranny jerk was related to glycol contamination in the tranny from the original OE Valeo radiators causing all sorts of corrosion inside the gears and what not. I could be wrong

Nonetheless, fuel injector cleaner really does help smooth out your idle and free up a bit of responsiveness if you haven't used it in a while. If you need it (injector cleaner), it's about on par with resetting the ECU adaptations (key position thing), changing old plugs/wires, or maybe cleaning dirty air filters. Not a bad butt dyno experiment for $4 or so, heh.

ohlord

the non mb spec,not ever to be used redline fluid in the 722.6 box,really takes out the transmission,then the real jerk will begin.
Seafoam injector and fuel system cleaner,for those that need cleaning.
Mb spec 722.6 fluid for those that like a long and happy 5 speed 722.6 life

SilverBulletAMG

Redline does have ATF that meets MB spec. It's called DC3 or something like that. Splinter had pointed it out in another thread and is what I'm getting ready to flush mine with.

I have used nothing but MB ATF, had the TCU replaced, updated, tranny pretty much completely rebuilt and all of this done with NO contamination present.

I've used injector cleaner in the past and that oddly enough fixed my gas gauge which was stuck on a full tank. Nothing has ever fully cleared the tranny jerk in my car. The reset is the only thing close and that is just a temp fix. Even getting my ECU tuned, which I was told would help significantly, only limited the jerk for the first few miles.

It seems some cars buck no matter what’s done or replaced. Glad the injector cleaner seemed to work for the OP but I highly doubt that would work for most.

SickSpeedMonte

Run the tank close to empty, pour in the injector cleaner just before filling the tank to the amount that the bottle says that the cleaner treats (dont run the engine with an empty tank and the cleaner added).

Glyn Ruck reccomended Techron Concentrate, and since he used to work in the petrol industry, I trust his reccomendation. I did this on two consecutive tanks and actually measured a 2 mpg increase with the in-dash display. It was $7 and change at the local auto parts chain IIRC. There is a thread in the W203 forum where a guy posted pictures of his valves with a boreoscope, and they are spotless because he fills up with chevron w/ techron. I only fill up with texaco w/ techron now.

///AMG4EVER

No offense in your discovery, but one problem has nothing to do with the other.