Revs Drop Slow

[matm3]

When i engage the clutch to shift between 1st and 2nd the rpms take longer to drop then they should.
Seems to only happen when im driving/shifting slow not during aggressive driving.

Is this common with the b6s4? Is there a problem?

Did a search, couldn't find what i was looking for.

Thanks in advance.

[Sunny4]

Dude, i feel the same way. This happens with other gears too. I have to wait a a sec or two for it to drop. Especially when im shifting slow and at lower rpms (below 2ish). I have had tons of people honk at me for slowing down too much between the 1rst to 2nd shift instead of having a gradual accel. No problems when driving aggressively as well. I have searched before to with no luck. At least,now I know I'm not alone...

[Lugi20]

I heard Southbend (correct me if I'm wrong) is coming out with a lighter weight, one piece flywheel. That will get the needle moving faster in both directions in the rev range. Something to consider getting if this really bothers you.

[40valve]

I've always had APR on my car so I don't have a frame of reference but I've heard that fixes it as well. If I remember to turn it off after work I'll do that and see how it behaves tomorrow.

[Sunny4]

I heard Southbend (correct me if I'm wrong) is coming out with a lighter weight, one piece flywheel. That will get the needle moving faster in both directions in the rev range. Something to consider getting if this really bothers you.

Are you saying this is normal for B6 S4's? And an upgraded flywheel is the solution?

[Sunny4]

I've always had APR on my car so I don't have a frame of reference but I've heard that fixes it as well. If I remember to turn it off after work I'll do that and see how it behaves tomorrow.

Can you be more clear? APR? Are you talking about the snub mount? A button like the ESP since you said you have to turn it off??

[nimski62]

Pretty sure a maf on it's way out can cause this as it did on my 325i/5spd. Code came on like 10k after the revs became slow. Just a thought

[pinkslip]

I've heard that a freer flowing downpipe helps with quicker revving as well. I will be doing Piggies as soon as I can get ahold of some stock B7 man trans downpipes. The Flywheel would probably be substantially more effective, but requires getting into the tranny/clutch and I don't feel like doing that until I need a new clutch anyway.

[matm3]

I heard a4 owners having similar problems...and the light flywheel took care of the problem.


seems weird the maf would cause this but who knows.
my esp light turns on during driving randomly which is tied to the maf....so maybe it is the problem

sunny4 do you notice this with your car also??

[b spot]

Hah, I have an APR flash and downpipes, and it doesn't fix this problem. A fly wheel won't do it either, as it's the ECU. The fact it's not a problem when bagging on it tells you it's not the fly wheel.

My throttle will also get 'stuck' and sit at about 3K rpm or slowly climb sometimes too. I've found no solution besides putting it in 6th and letting the clutch out to force the revs down.

I also find the slow rev drop totally inconsistent, and highly frustrating.

[Slobo7x]

granny shifting, not double clutching like you should.

[shifty711]

I know exactly what your talking about.

My car will do this once in a while. Some times if I am just hanging at a light and I blip the throttle it will seem to come down really slow.

I think this is an ECU issue. Our cars have Throttle by wire, and I think for whatever reason sometimes the ECU keeps the throttle open. Glitch??

It is strange no doubt, and very difficult to duplicate, so Im sure you will never be able to get the car to do it at the dealership. But, it has never cause me harm. I think it is entertaining actually.

I wouldnt be worried.

I would bet my car that it is an ECU Throttle by wire glitch. I dont think it will be harmful.

[RudeBwoi]

from what I understand, the heavier flywheel is what makes for smoother shifting in the car. It creates a more refined shifting experience. The lighter flywheel makes a big difference in the driveability of the car in the sense that it takes away SOME of its refinement for the speed of the rpm drop. That tight, solid shifting feel you guys feel has SOME parts to do with the heavier flywheel.

[b spot]

^And the dual mass flywheel.

Driving tonight, this happened zero times. Hurray. I've often wondered if it's weather dependent to. Sometimes it happens every day for a while. And oddly enough, at the EXACT same place on my drive to work, a tight downhill curving onramp. Even if I was stuck in traffic for an extra 10 minutes earlier, it will still happen right there. So odd.

[Sunny4]

Hmmm....from the discussion I find the ECU/Throttle by Wire reason to be the most probable but i'm not too mechanically inclined. And Yeahhhh!! its gona be hard to tell the dealership and they're just going to dismiss it as a "thats normal with theses cars." I wonder if it being a safety issue will get them moving, I swear one of these days some ******s going to hit me from the back cause im driving conservatively while shifting from 1rst to 2nd and hes too busy picking is nose instead of watching the road. Is there an ECU upgrade or something that would take care of it and I mean stock wise...any TBS about this? Man I really would like to take care of this problem.

[RudeBwoi]

you need a light weight flywheel. The slow rev drops are "normal". It'll change ur driving dynamics, but ur revs will drop much faster

[Sunny4]

Took the S to the dealer yesterday for a coolant leak (which I physically witnessed a few days back) and also told them to look at the rev issue. Got a call this afternoon and what they say? Apparently they could not find it, they did hundreds of tests and checked every inch of the car including the oil pan and nothing, no sign at all, no residue, nothing...weird...whateva atleast the news is I dont have a leak right? Well on to the brighter side of my 1 hour drive to and back from naperville, IL today. I had a tech drive with me today and luckily I was able to duplicate the problem with the rev's dropping/sticking when shifting at low rps. For my car this is only an issue thru gears 1-4. He was not sure exactly what was causing the problem but agreed with me that it is not normal. He said that he would talk to his head foreman and see what he says. Well I couldn't wait another day without her so i decided to bring her home. Oh and my constellation prize for the trip was that the porter broke my gps window mount because he just ripped it off the window or the rental without thinking. Good thing is, that they will replace it. Just gotta send em a copy of the receipt of the new one I buy. All in all it wasnt so bad. The dealership I frequent is Continental Audi of Naperville. Their customer service has always been up most best everytime I have had to go there. I have nothing bad to say about them and would recommend anybody who wants to do warranty work to go to them. The Service person that helped me out was Shanan, and she was very helpful. Hopefully they will figure out what the issue is and I can pass it on to you guys. Wish me luck! :)

[ZachPDX]

granny shifting, not double clutching like you should.

Now me and the mad scientist have to rip apart the block and replace the piston rings you fried.

[Monchichi8]

I know exactly what your talking about.

My car will do this once in a while. Some times if I am just hanging at a light and I blip the throttle it will seem to come down really slow.

I think this is an ECU issue. Our cars have Throttle by wire, and I think for whatever reason sometimes the ECU keeps the throttle open. Glitch??

It is strange no doubt, and very difficult to duplicate, so Im sure you will never be able to get the car to do it at the dealership. But, it has never cause me harm. I think it is entertaining actually.

I wouldnt be worried.

I would bet my car that it is an ECU Throttle by wire glitch. I dont think it will be harmful.

Correct sir. mine does the same thing every so often. I hate it but it is what it is. I think a reflash does cure this problem. APR/REVO/GIAC

[40valve]

Correct sir. mine does the same thing every so often. I hate it but it is what it is. I think a reflash does cure this problem. APR/REVO/GIAC

I can't tell how often this happens on stock ECU because mine has been APR flashed since day one but occasionally it happens to me as well. Either yesterday or day before I was downshifting from 3rd to 2nd and RPM's just stayed at 3K for like 5-10 seconds. But I can't remember when was the last time it did it.
My RPM's do drop pretty quickly. I finally remember to turn the stock mode on last night so I'll drive it like that for few days and see if there is any difference in how RPM's drop.

[pinkslip]

Took the S to the dealer yesterday for a coolant leak (which I physically witnessed a few days back) and also told them to look at the rev issue. Got a call this afternoon and what they say? Apparently they could not find it, they did hundreds of tests and checked every inch of the car including the oil pan and nothing, no sign at all, no residue, nothing...weird...whateva atleast the news is I dont have a leak right? Well on to the brighter side of my 1 hour drive to and back from naperville, IL today. I had a tech drive with me today and luckily I was able to duplicate the problem with the rev's dropping/sticking when shifting at low rps. For my car this is only an issue thru gears 1-4. He was not sure exactly what was causing the problem but agreed with me that it is not normal. He said that he would talk to his head foreman and see what he says. Well I couldn't wait another day without her so i decided to bring her home. Oh and my constellation prize for the trip was that the porter broke my gps window mount because he just ripped it off the window or the rental without thinking. Good thing is, that they will replace it. Just gotta send em a copy of the receipt of the new one I buy. All in all it wasnt so bad. The dealership I frequent is Continental Audi of Naperville. Their customer service has always been up most best everytime I have had to go there. I have nothing bad to say about them and would recommend anybody who wants to do warranty work to go to them. The Service person that helped me out was Shanan, and she was very helpful. Hopefully they will figure out what the issue is and I can pass it on to you guys. Wish me luck! :)

My condolences for your car woes. I hope the service staff's helpfulness was enough consolation. I guess the stars weren't aligned in your favor. Then again, I try not to put any significance in a constellation.

In all seriousness, though, I hope you don't have a real leak that they misses. Keep us posted on the rev-drop issue. I hope your dealership has heard of that before.

[Monchichi8]

I can't tell how often this happens on stock ECU because mine has been APR flashed since day one but occasionally it happens to me as well. Either yesterday or day before I was downshifting from 3rd to 2nd and RPM's just stayed at 3K for like 5-10 seconds. But I can't remember when was the last time it did it.
My RPM's do drop pretty quickly. I finally remember to turn the stock mode on last night so I'll drive it like that for few days and see if there is any difference in how RPM's drop.

Please do! From what I understood, it was the ECU but I'd love to know how to really cure this problem.

[b spot]

Playing around It seems that the revs drop slower if you are below 3000rpms when you shift (which I would imagine is to allow you to not rush your shifts if you're just cruising around calmly) and drop much faster if you shift when above 3000rpms (so if you are accelerating hard they drop fast enough for smooth shifts).

*I have APR

[40valve]

After only one short day of driving I'm already experiencing some results in RPM dropping slower. Or at least they stay at the spot where they were when you clutch in for a bit longer and not necessarily drop faster all the way down, if that makes sense. I'll keep the stock program until I fill up again just to see if there is any MPG difference too.

[isb]

I think I read some time ago that the slow drop off in revs was due to emissions management - emissions are higher when the air intake is shut off quickly. If so, that might explain why the flashed cars behave differently.

[serumk]

I had my revs drop slowly just before my MAFS needed to be replaced. Now my revs drop so fast that I need to hurry my shifting to keep up.

[Audi0s]

I think I read some time ago that the slow drop off in revs was due to emissions management - emissions are higher when the air intake is shut off quickly. If so, that might explain why the flashed cars behave differently.

Yes, usually when revs fall off slowly, its the emissions system trying to lean out the mixture. If the throttle plate is closed, injections go back to idle settings, but there is not enough air in the plenum to get to the 14.7:1 desired for complete combustion at revs. Therefore hydrocarbons spike, and HC's are a no no to the EPA. So, they keep it cracked a little to let air in, but the side effect is slower falling revs.

[CtS4Driver]

Ive figured out a way to duplicate the throttle hanging open issue in second gear, driving like 25 or so in second, gently blip the gas, then let go, and my car rpm hangs around 3k and the damn car just keeps going, very dangerous if you're not aware of it in traffic...

[40valve]

OK, I've been driving on a stock mode for few days now and the only thing I can tell that is different is, like I mentioned before is that RPM's sit at the clutch engagement for a little bit longer.

[Sunny4]

OK, I've been driving on a stock mode for few days now and the only thing I can tell that is different is, like I mentioned before is that RPM's sit at the clutch engagement for a little bit longer.

Thats the problem! The longer the time for the rpm to drop the longer the shift process.

[40valve]

I actually don't mind it for stop and go traffic to work and back.

[earnhardtJR]

Sorry to revive this old thread.... did anyone find a solution to this problem, or is it just considered normal?

I have a CPO 2004 S4 with a manual, but even with it being under warranty, there is no way I am going to take it to the dealer and have them take 2 days to diagnosis it as "normal". Here are all the symptoms; I think they are all related:

1. CEL has come on and gone off twice in the past year (for about 2 days at a time). Both times, the dealer hasn't been able to do anything because the light went off by the time the dealer has seen it. Scanning the computer revealed a "lean condition", most likely caused by the MAF going bad (per the dealer).
2. When the motor is cold, the RPMs don't stick when I let out the clutch; they fall immediately and the shifts are smooth. When the motor heats up, then the RPMs hang when I let the clutch in for 1-2 seconds, especially at RPMs under 2.5k.
3. With a warm motor, the throttle response is bad (sort of like the engine is bogging). Shifts are impossible to get smooth- if I shift too fast, the RPMs are too high and the car surges when I let the clutch out. When I hit the unresponsive gas pedal, there is about a 0.5 second lag before the revs come up. So the shifts are basically like this- accelerate, clutch in, rpm's hang, next gear, clutch out, surge because the high rpm's, bog because of sluggish gas pedal, repeat. Not very fun to drive. Sometimes this bogging is worse than other times.
4. Sometimes if I take off from a slow roll in second gear (possibly other gears as well, but most obvious in second because of the steeper gear ratio), the motor feels like it is chugging to go from about 1k rpm until 2k rpm. After that, the motor runs smoothly.
5. Motor sometimes idles rough for about 2 seconds when sitting at a light. Revs drop by about 50 rpm, and the car shakes ever so slightly. Then the revs come back to normal and idles smoothly.

I am thinking this is a MAF problem. If something is going wrong with it, the problem will be most apparent when there is only small amounts of air flowing past it (which happens at very slight throttle openings). Maybe I am just trying to convince myself that this is the problem, but I can rationalize how every one of the problems above could be caused by a bad MAF. I am going to do the 55k service this weekend, and possibly change the MAF as well too see if the problem gets resolved.

Did anyone figure out what was going on with their own issues? Any remedies before I start replacing everything on the car?

[S4DTM]

Sounds like Throttle Body...I'm having the same problem and after VAGing it myself and having the dealer check it out, it was determined my throttle body is going bad. I'm working with AOA and the dealer right now to try to get it replaced...but we'll see. Good luck man

[earnhardtJR]

Sounds like Throttle Body...I'm having the same problem and after VAGing it myself and having the dealer check it out, it was determined my throttle body is going bad. I'm working with AOA and the dealer right now to try to get it replaced...but we'll see. Good luck man

Bummer... the fact that it is an intermittent problem on my car means that there is NO way the dealer will fix it. They will just give me the old "we never saw the problem while we had the car" line. When I had the starter going bad in my car (when the car won't even turn over for cold starts), I left it with the dealer for 2 weeks only for them to tell me that the car started fine every day. The week that I got the car back, it wouldn't start 5 out of 7 days.

Please let me know you get your problem resolved! If it turns out to be the throttle body, at least I can approach the dealer and use your case as by basis for diagnosing the problem with my car. Thanks!

[GotRS?]

Intreresting post. I've noticed pretty much all cars now have this issue to a various level. When I complained about this over ten years ago about my then new car, it was explained as "the new emissions requirement" where the engine needed to have more gradual off-throttle change.
It's a common issue, and the B7 A4 series has a weird way of lifting the revs up when you let off, you can experience that on a dyno at the end of a pull, I've seen them rev right up again.
My son's car (not Audi) has recently been used by an ECU tuner to investigate removing the serious hang on that model.

[loucura]

having the same issue.. sometimes shifting between 1st, 2sd and 3rd RPM is taking longer than usual to drop...

Yea..keep us posted.

[drew]

i wonder if this is a problem on 2004 and later cars only. not pre 2004.

supposedly the U.S. laws got a lot tougher on emission standards going from 2003 to 2004 MY imported vehicles, especially in california.

i know for a fact that the 2004 run of the lotus esprit had to be labelled as 2003.5 vehicles in california due to the regulations changing. if they wanted to call it an actual 04 car, lotus would have had to change quite a few things supposedly. rather they made a deal and listed them as 2003.5 cars in california.

hmmm....

[S4DTM]

AOA explained to me that the 07 model year wasn't covered because the "cost to replace the throttle body wasn't high enough for CA to fix the problem." How this changes from 06 and 08 I have NO idea, haha. But they did agree to cover half the cost of my repair, so I'm pretty happy with that since I'm out of warranty. Will let you guys know the difference when I get the new one in next week

[nuklearmaniac86]

try shifting in this manner... accelerate, let off gas completely, then depress clutch in completely, shift, let off clutch completely. see if that helps any? I have to do that for my 1-2 shift because it is so long.

[S4DTM]

try shifting in this manner... accelerate, let off gas completely, then depress clutch in completely, shift, let off clutch completely. see if that helps any? I have to do that for my 1-2 shift because it is so long.

You really should be giving it some throttle input when you engage the 2nd gear, otherwise you'll have wear issues over time. And it doesn't have to do with my shifting style, I can get the revs to stick in neutral just giving it a small amount of gas. I originally just thought my throttle valves were dirty, but I was wrong, haha.