RPM Surging, or Transmission slipping? Automatic

[SacAudi]

Hi Guys,

I have done some extensive searching around this website as well as others and I havent actually found anything definitive around the S4 (b6) Specifically

Symptoms
-Light throttle transmission feels like it is slipping slightly, or torque converter is slipping slightly. The RPMS surge, or bounce 100-200 RPM's back and fourth as the speed increases.
-Doesn't actually shift gears, it just sloppily bounces/surges as it accelerates in whatever gear it is in.
-Happens less in S or TIP but still happens
-Transmission does not slip in any gears hard on the throttle, shifts are crisp and quick. Overall aggressively driving everything seems perfect. It is just rolling on the throttle or cruising around. Very annoying when cruising on the freeway.

I just bought the car and it has 140k so I know there is the potential that things are shot, but it runs GREAT. when i test drove it I mostly drove it hard to test for obvious issues so I didnt see these issues.

The b8 a4 discussion perfectly describes the issue, some say its a transmission programming update, some say an ECU, some say to change the fluid/filter.

I dont know the age of the fluid/filter so that is going to be my first place to look, but it would be nice to know if this is just the torque converter/transmission being shot, no point changing fluid if i need a new transmission.

Thanks for all of the help guys!

[SpoolBus]

Maybe you could post a video of the problem to better diagnose?
Does it feel like the engine is skipping/misfiring at all?
Did you scan the car yet?

[nick447]

Have you checked to make sure all the hoses are not leaking? I had my RPM's jump due to a hose not being properly secured.

[p3u]

Without a video can't say for sure, but the way you described it sounds like the torque converter just regulating, going from open to close hence the slight rpm jump.

Post a video though.

[Sean21]

At 140k miles gearbox oil will be a little worse for wear, especially if it's been worked hard.

I had similar issues on my B7 Tip. Changed the oil and filter last year and it was surprisingly rejuvenating. My car was only on 70k.

Make sure you get the right gearbox oil... I had conflicting specs from main dealer/specialists/retailers before eventually finding the right spec... however all had the consensus that the wrong oil will likely be detrimental.

HTH.

[SacAudi]

Have you checked to make sure all the hoses are not leaking? I had my RPM's jump due to a hose not being properly secured.

Which hoses are you referring to? I will have to check.

Without a video can't say for sure, but the way you described it sounds like the torque converter just regulating, going from open to close hence the slight rpm jump.

Post a video though.

If this was the case, does that mean the torque converter is going out? Can you articulate? I will make a video and then post it.

At 140k miles gearbox oil will be a little worse for wear, especially if it's been worked hard.

I had similar issues on my B7 Tip. Changed the oil and filter last year and it was surprisingly rejuvenating. My car was only on 70k.

Make sure you get the right gearbox oil... I had conflicting specs from main dealer/specialists/retailers before eventually finding the right spec... however all had the consensus that the wrong oil will likely be detrimental.

HTH.

Can you post the proper spec/brand. I see JHM has a service kit, so I would assume this is the right one, but I would hate for this to be the issue and then just re-create the problem with the wrong spec.

Thanks guys!! i will get a video asap

[SpoolBus]

It might not even be the transmission
Again did you scan for codes? Does it feel like a misfire?

BTW you can't beat the price of this kit with what's included.
Works great just used it
http://www.blauparts.com/audi/audi_f...on_fluid.shtml

[S4orgy]

[QUOTE=SpoolBus;9565068]It might not even be the transmission
Again did you scan for codes? Does it feel like a misfire?

My car is spuddering/surging not exactly sure what to label mine but mine is throwing misfire codes. I already replaced, vcg - ngk platinum plugs -coil packs- pcv valve.

Also anybody know how tight the oil sensor needs to be?

[SpoolBus]

Misfire codes on what cylinders?

If on specific cylinders remove the coil and plug from one with no code and replace with one with code to see if the problem follows.
There are a lot of potential issues but bad, brand new, coils happen as well as bad plugs (gaps etc).
Check MAF as well
These are good starting points

If continues get a compression check, the flapper has been known to come apart on higher mileage engines thus a compression test would help identify a problem.
If all comes back good start to check chain guides.

Another check list;
1) check and clean MAF sensor (new one is $30)
2) check fuel pump (i doubt anything is wrong with it.)
3) replace cam shaft position sensors ($30)
4) replace spark plugs, coil packs, and injectors (which you did)
5) check the chain tensioner.

[rixonichard]

My tip does this but only when cold. It's a known issue that the OEM torque converter slips on light throttle before it warms up. I changed my trans fluid and it didn't help.

Sent from my RM-820_nam_att_100 using Tapatalk

[Sean21]

Oil spec depends on your chassis code. Tbh best thing is to read gearbox code under car on transmission and use corresponding oil.

I would not recommend using anything but genuine oil on a high mileage change. Look for prices from ZF themselves to avoid Audi markup (after all these are ZF boxes.)

Any reputable gearbox specialist that has experience with this range of ZF boxes will advise that unless you are filling from a rebuild that you should use the same oil spec of the same brand as was removed as anything to the contrary has led to dead 'boxes. Especially high milers.

[jjrichar]

A car with 140k definitely needs the transmission oil changed. With the symptoms you have, it does sound like the TC clutch slipping. The best thing you can do for this is change the oil.

As far as what oil to use, it doesn't have to be the genuine ZF. It does have to be the correct spec. I think the spec is ZF LifeGuardFluid 6+. Have a look at the links below, and confirm with the transmission you have. It should be a ZF 6HP19A. Many oil manufacturers make an oil of this spec. With a transmission of this age, personally I would do an oil change, drive for a week and then do it again to get as much new oil in as possible. It's very difficult to replace all the oil in one hit. The first oil change I would do the filter as well.

http://www.zf.com/media/media/docume...9A_Catalog.pdf
https://www03apps.zf.com/interoelepd...011_en0700.pdf

[TexS4]

At 140k miles gearbox oil will be a little worse for wear, especially if it's been worked hard.

I had similar issues on my B7 Tip. Changed the oil and filter last year and it was surprisingly rejuvenating. My car was only on 70k.

Make sure you get the right gearbox oil... I had conflicting specs from main dealer/specialists/retailers before eventually finding the right spec... however all had the consensus that the wrong oil will likely be detrimental.

HTH.

X2 on this. Around 70k miles my car started doing the same thing after I drove through what seemed like a monsoon. My car hydroplaned a few times and afterwards is when I started noticing the transmission starting to act up; it was really weird and I wasn't convinced anything mechanical was wrong.

After scanning the car with no luck, I decided to changed the fluid and filter and we found no shiny flakes or residue. Put the car down off the lift, took it for a drive and right away you could tell the issue was gone.

For what its worth I'm running Motul fluid in the transmission with an OEM filter.

[SpoolBus]

X2 on this. Around 70k miles my car started doing the same thing after I drove through what seemed like a monsoon. My car hydroplaned a few times and afterwards is when I started noticing the transmission starting to act up; it was really weird and I wasn't convinced anything mechanical was wrong.

After scanning the car with no luck, I decided to changed the fluid and filter and we found no shiny flakes or residue. Put the car down off the lift, took it for a drive and right away you could tell the issue was gone.

For what its worth I'm running Motul fluid in the transmission with an OEM filter.

This may have been a coincidence and sounds like your evap filter got wet (upper driver rear wheel well) this will cause the car to run rough if water got in the vent or down into the tank.

If your transmission ingested water you would have seen it in the fluid and it would have been a mess

The engine misfiring can easily feel like a drive train issue as it affects the power to the wheels (feeling like a slip, surge etc)

[SacAudi]

Here is a video doing it between 50-60. It was kind of hard to video and drive in traffic at the same time :)

https://www.youtube.com/watch?v=v2Os...ature=youtu.be

[TexS4]

This may have been a coincidence and sounds like your evap filter got wet (upper driver rear wheel well) this will cause the car to run rough if water got in the vent or down into the tank.

If your transmission ingested water you would have seen it in the fluid and it would have been a mess

The engine misfiring can easily feel like a drive train issue as it affects the power to the wheels (feeling like a slip, surge etc)

You make a very good point. This was a flash flood style rain storm and the highway was literally under water in some spots so things got wet. The car didn't run rough though as in the motor didn't misfire (we didn't have any codes at all) but you could certainly feel the transmission slip in drive more so than S mode or TIP.

In fact I drove it in TIP for several days until we fixed it so I could control the shifts better which helped the transmission from slipping. Mine slipped between 2nd and 3rd every time and only twice in 4th. 1st, 5th and 6th were normal. My shop's conclusion was "something got wet" which I know is vague but we really don't know what "it" was. Changing the Tranmission fluid though seemed to really help as the car ran normal again the first time after changing it.

[SacAudi]

Anyone get to watch the video? Any thoughts?

[rixonichard]

Looks almost exactly like what mine does when it's cold. It only happens on light throttle while cruising around 40-50 mph. Looks like your torque converter is slipping. If it is there is nothing short of swapping in a new TC that will fix the problem. I haven't bothered fixing mine because as soon as the tranny warms up it stops surging. It's not hurting anything to drive it like that so I figure I'll just drive it as is.

Does it surge after it's warm or at other speeds? Search rpm surge and you'll find lots of people who've run into this same issue and had to replace their TC to fix it. It's a known issue. Since putting it is S mode affects it I would say you could pretty much be certain it's a transmission issue.

From what I've read 517 trans makes the best aftermarket TQ for our cars.

[SpoolBus]

^ I would agree with that statement (with the video)..but such a quick surging you may be able to be minimized with a fluid change

[vdawg0003]

Dont mean to resurrect an old thread but I'm experiencing same issue as well. Wanted to know if @SacAudi fixed the issue. I get similar RPM surges, 100-200 rpms at normal driving speeds, during cold and normal operating temps. Also having slippage at take off with a combination of exhaust leak. Sometimes i'll be driving at a slight incline in 4th or even 5th gear and it just slips. I thought that it's time to change the ATF w/filter and I did just that yesterday, but still having same issues. I came across this thread and it sounds like i'm about to run into a nightmare repair if this is a shot torque converter.


EDIT: When changing the ATF noticed there is a tranny fluid leak, not sure where its coming from yet as its kind of spread out. Best way i can describe the location is below the drive axles, between the fluid pan and TC. I guess the transfer case maybe?

[VinnysS4]

Your seal inside your torque converter is bad... this causes the 100-200 RPM "hunting". A fluid change will do little to nothing to help

[Erod]

Yep, mine does the same thing, just got a 06 S4 Avant, with 209k and no maintenance history, but it seems really well maintained

[vdawg0003]

Your seal inside your torque converter is bad... this causes the 100-200 RPM "hunting". A fluid change will do little to nothing to help

what's funny is i drove the car for the past two days since changing the ATF and both days I haven't had those symptoms of the rpm surging and slippage when taking off, i've tried to re-create/force the issue but it's just not occuring now for some reason. I'm going to give it another week and see how it goes.

[KrazydanB5S4]

2001 Audi S4 I have the exact same issue curious if you ever figured out the problem. I replaced the torque converter with a remanufactured one from torco. And nothing changed car does the exact same thing.

[ZimbutheMonkey]

Your seal inside your torque converter is bad... this causes the 100-200 RPM "hunting". A fluid change will do little to nothing to help

Vinny's close, but it's not the seal in the TC that goes bad. What goes first are the seals between the valve bodies and the trans body. Then the pressure loss causes the TC clutches to slip and burn out in short order.

ANYONE WHO IS HAVING THESE SYMPTOMS NEEDS TO WATCH THIS VIDEO BELOW, CALL COBRA TRANSMISSION THAT SAME DAY AND ORDER THE PARTS THAT THEY CHANGE IN THE VIDEO

Do NOT delay, if your transmission is slipping, it may already be to late to salvage it. But if you change the VB seals, you may be able to save your trans for $200-300 instead of a $3000+ rebuild.

This video should be stickied for anyone with a tip tranny

https://www.youtube.com/watch?v=2g-5uY_P7uA&t=722s

[Mal]

I just saw that this post was resurrected and figured I would share the little bit of knowledge I have...Technical Service Bulletin 2028608/1 states that there is a TCU update. Do the update. If that doesnt fix the issue, check fluid color/ level. If that is fine, then replace torque converter. My car has the issue ('04 S4 Avant) and I am currently going through the steps necessary to fix this annoying problem.

[SFI]

Vinny's close, but it's not the seal in the TC that goes bad. What goes first are the seals between the valve bodies and the trans body. Then the pressure loss causes the TC clutches to slip and burn out in short order.

ANYONE WHO IS HAVING THESE SYMPTOMS NEEDS TO WATCH THIS VIDEO BELOW, CALL COBRA TRANSMISSION THAT SAME DAY AND ORDER THE PARTS THAT THEY CHANGE IN THE VIDEO

Do NOT delay, if your transmission is slipping, it may already be to late to salvage it. But if you change the VB seals, you may be able to save your trans for $200-300 instead of a $3000+ rebuild.

This video should be stickied for anyone with a tip tranny

https://www.youtube.com/watch?v=2g-5uY_P7uA&t=722s

Thanks for the link to the video, it’s interesting but he doesn’t mention lockup clutch slip as a symptom of those seals being bad, he only seems to talk about harsh downshifts from 2 to 1.

My car (2007 A6 Allroad with 3.2 and ZF 6HP19A) has this rpm fluctuations issue, where on cold days at low revs (1400rpm) in 5th or 6th the tacho needle will bounce up and down. I’ve monitored the transmission in vcds and see the TC is constantly in “control” or “reg” mode, with alternating 0/32/64 rpm slips. No harsh downshifts from 2 to 1 as the guy in the video mentioned.

I’m aware I’m posting in an A4 forum, but from the description it does seem to be the same issue so I’m very motivated to find out of changing these valve body seals might fix my issue.

My questions - what makes you think it’s these seals which cause this issue? Have you, or anyone else on here changed these seals and resolved this issue as a result? Thanks for any help

[blue.monday]

I have similar symptoms, higher gear low revs it bounces a little, usually around 2000 rpm. I'm getting it mapped next week so we'll see if it's a software issue then i guess.

[ZimbutheMonkey]

I have similar symptoms, higher gear low revs it bounces a little, usually around 2000 rpm. I'm getting it mapped next week so we'll see if it's a software issue then i guess.

I wouldn't waste a lot of time on software based solutions. As I've been so adamant, the issue with these transmissions is in the valve bodies.

If you weren't already having problems I'd be replacing the mech to VB seals and the sleeves as a preventative issue. If you're having fluctuation issues, that means that there is a worn bore in the VB which needs a Zip kit from sonnax.

My advice is CALL THEM, they will be able to tell you better than the dealer (who really knows sweet fuck all about auto transmissions other than to tell you that any problem will require a rebuilt transmission).

But again DO NOT DELAY, if you overheat that TC clutch, you're having to pay to have the entire trans dropped and you will likely do damage to the rest of the transmission as the overheated fluid from the TC slipping will take the friction material off the remainder of the internal A-E clutch packs.

Let me make this clear to all members here YOU DO NOT GET A SECOND CHANCE WITH AUTO TRANSMISSIONS AND WHEN YOU HAVE RPM FLARING IT'S A SERIOUS ISSUE WHICH WILL EVENTUALLY DESTROY THE TRANSMISSION.

The fact is, there is a $600-800 solution in the form of the zip kit which uses O rings on the pistons instead of the regular machined piston which relies on the tolerances between 2 machined metal surfaces to maintain pressure.

In any event, don't mess around with hopeful and easily fixed solutions for RPM flaring. It's a pressure issue, the only way to fix a pressure issue is to address the leak.

Also, a valve body is not that hard to service. Literally replace the parts as you remove them one by one. If you can put a Lego set together you can install a zip kit...