Anyone experience a hard jerk kind of motion when shifting into second if your RPM level is above like 2500-3000. How can you shift fast and smooth at the same time. I almost have to start off slow in order to not rock the car. Is this just me or what. Is there something wrong with my trans?

Hi Mike. I've had my '99 A4 1.8T QMS for about 4 weeks now. I've found the manual transmission to be silky smooth. I've driven manual transmissions all my driving life, 14 years.<br>One thing I've noticed, and I've seen mentioned here before, is that the flywheel on the 1.8 (don't know about the 2.8) seems heavy. By that I mean that your rpms can increase in between shifts if you're doing any sort of spirited acceleration. So, if your accelerating in 1st up to 3k rpm and go to shift to 2nd, you'll probably be letting out the clutch at a higher rpm than when you disengaged (pressed in) the clutch. This can make shifting smoothly a little more difficult, but certainly not impossible.<br>Maybe some of the racing folks in the forum can give you some more detailed advise than this.<br>Good luck!<br>'99 A4 1.8T QMS Silver/Ecru gray, Winter mats

I have 2.8 QMS and found it hard to shift smoothly. You either have to push the clutch and delay a second or two before shifting or you can blip the throttle while shifting to a higher gear to match RPMs. I got better with practice. My 90 Prelude seems much easier to shift but I attribute that to the lack of power and that I have been driving it 9 years.<p>Mark (98.5 2.8 QMS)

By momentum, I assume you mean that because the engine speed is increasing under acceleration, it will continue to increase even after you release the accelerator. But, that wouldn't happen if no additional energy were being added. Even in a frictionless environment, the best you could expect would be no decrease in engine speed, not an increase.<p>Instead, what I assume is happening is that the engine is getting enough fuel to continue accelerating--that is, the throttle doesn't close immediately when the accelerator pedal is released.<br>

The dealer suggested that it was the turbo bypass, not sure how true this is as I haven't taken the thing apart (I'm not an authority, I just asked after I had driven the demo before I bought my car), but what he said is that when the throttle closes a bypass opens so that the turbo revs stay up, retaining the boost after the shift. I have also seen it suggested here that the flywheel is heavy, both would cause the engine to hang on though. The engine doesn't accelerate like it has a particularly heavy flywheel though.

I've copied a post by Ray Calvo on this subject from 1/17. He's a pretty knowledgeable guy, much more so than I on this mech stuff. I was wrong earlier (thanks for correcting me Eric E.) in saying that momemtum accounted for the revs increasing after the clutch is pressed in. Ray's post goes to the heard of this issue and it seems like the revs not dropping off quickly really bothers him, me too a little bit.<p><<This is the propensity for the engine to decrease RPM extremely slowly between upshifts. I actually have to pause in neutral for several seconds before engaging clutch when upshifting to a higher gear. I have actually started lifting my foot off the gas a significant time BEFORE the clutch is disengaged to avoid the RPM from actually momentarily speeding up slightly.<p>Anybody found a cure (I don't care - cut a wire, pull a fuse, change a computer chip)?<br>>>

1) Is this an upshift or downshift?<br>2) Engine (1.8T or 2.8 - 12V or 30V)<br>3) Technique you use?<p>Also , HAVE YOU CHECKED ARCHIVES?<p>if it is a 30V and problem is 1st-2nd upshift, agree with you. Engine will not drop speed fast enough to match revs in 2nd. On a normal shift, can actually watch revs speed up momentarily between shifts. I have started getting into habit of letting off gas a split second before disengaging clutch; avoids engine "rev-up" and lets RPM drop faster. Can then engage clutch in 2nd with revs at desired value without major pause in neutral. <p>If problem is downshift from 3rd to 2nd, I "heel-&-toe"; hold brake with instep of foot, blip throttle to speed up engine with toe. Littel different than "traditional" heel-&-toe, but works nicely.<p>I think your only problem is with the "nut behind the wheel". A4 clutch to me is a little grabby, and smooth driving techniques are needed to avoid looking like a klutz. I'm still not perfect with my Avant (9000 miles so far), and have been driving manual trannies since 1968 (close to a million miles on them).

it's part of the new and improved emissions equipment. Apparently keeping the revs up between shifts lowers tailpipe emissions.<p>But I'm not an engineer, I just play one on television, so I could be wrong.<br>

This is the propensity for the engine to decrease RPM extremely slowly between upshifts. I actually have to pause in neutral for several seconds before engaging clutch when upshifting to a higher gear. I have actually started lifting my foot off the gas a significant time BEFORE the clutch is disengaged to avoid the RPM from actually momentarily speeding up slightly.<p>Anybody found a cure (I don't care - cut a wire, pull a fuse, change a computer chip)?<br>

This is not caused by momentum or the weight of the flywheel or fuel flow or a delayed tach. As part of the emission control system, it prevents the throttle from quickly snapping shut, which affects the amount of hydrocarbons in the exhaust. This is controlled by a vacuum-operated device called a dashpot, which is connected to the throttle linkage. It was widely used in the mid 70s for emission control on carburated engines. If you don't like the RPM hanging between shifts, you might try disabling this dashpot. It's black, about 2" in diameter, has a vacuum hose attached with an arm that connects to the accelerator cable pulley on the throttle body. It's located at the top rear of the engine, under the plastic shroud. Disconnect and plug the hose or pop the arm off the pulley end. Just shifting a bit more slowly will alliviate any problem here and save the syncros from undue punishment. If you like power shifting, buy a Camaro. <br>

The A4 2.8 has air bleed valves which add slight additional throttle to prevent stalling. I've heard its drive by wire but I still see a throttle cable. <p>Keith

I know, I yanked the vacuum hose and plugged it, then drove the car. Still had the RPM "hangup" problem, but cruise was dead. <p>I looked around the back of the engine underneath the engine shroud, but couldn't see what else could control it (couldn't even see a throttle cable - these cars are getting beyond my "shadetree mechanic" abilities).<br>