3.0 tdi revs pulsing when lifting off (Video taken)

[Chriseybaby]

The other annoying feature of my car is how the revs pulse when I lift off. (see video below)

https://youtu.be/AssK9uqka3U

My research firstly indicates the throttle body could cause it, any other suggestions before I go pulling the car apart?

[Chriseybaby]

Ok so I cocked up the link to start with. It should now be the correct link

[Toni Hughes]

Are the engine revs ACTUALLY wandering, or is the needle faulty?

[Chriseybaby]

Yes the revs are wandering, you can feel the car pulse as it slows down.

[Guest 2]

did you buy it from a trader?

[Crasher]

Get it fault code read.

[Chriseybaby]

No I didn't buy from a trader :(

Do you think there will be a fault code showing even though the warning light isn't on?

[Crasher]

Quite possibly but not definitely. It only tends to come on if it is a potential emissions problem.

[royclark]

My 2008 2L TDI used to do this and it had only done 8k so I traded it in for a face lift 2.7 TDI.
I could not get an answer as to why it was doing it.

[gupsterg]

^^^ bit drastic solution Roy? ;) but wish I'd done the same with my car ages ago! :biglaugh: ...

[Chriseybaby]

Not really what I was hoping to hear Roy.

If nothing shows up on the scan are there any thoughts on what might cause this?

Thanks

[MarkTM]

Youve not stated (in this thread at least) what year your car is:confused:

You've also no said how long you've had the car and if it has always done this?

We're not clairvoyant so a scan is the first place to start :biglaugh:

[gupsterg]

We're not clairvoyant ...

http://www.reactiongifs.com/r/dsgstd-nrd.gif

[Chriseybaby]

Sorry car is a 2007 (07), i've only had the car 3ish weeks and its always done it I just didn't notice it when I test drove it!

It seems a lot worse while the engine warms up but still does it when the engine is warm.

[gupsterg]

Yours car's pulsing revs issue is the opposite way around to Cwizards. His did it when deaccelerating, AFAIK he never got it fixed. IIRC last time we chatted (ages ago) he was thinking of selling it.

View video in this post (after 1min or so you see it), Link:- A6 3.0 TDI QUATTRO numbers (http://www.vwaudiforum.co.uk/forum/showthread.php/139736-A6-3-0-TDI-QUATTRO-numbers?p=769136#post769136)

IIRC he was gonna get gearbox oil flushed & refilled, perhaps some info in his past posts/threads.

[royclark]

^^^ bit drastic solution Roy? ;) but wish I'd done the same with my car ages ago! :biglaugh: ...

Truth is Gup. I was looking for a decent excuse to give the wife to get a facelift model, as we had only had the 2L six months with only 8k on the clock.
In the end it only cost me six grand + the 2L TDI for a much better car.

[Chriseybaby]

No Gup mines the same as Cwizards, its pulsing when deaccelerating.

I too am thinking of a gearbox oil change but I doubt thats going to help much. I can live with it and certainly wouldn't want to go down the new gearbox route so hopefully there is a simpler fix.

[gupsterg]

Ahh I see now, post 1 stated when I lift off , post 4 state decelerate.

Sorry got no pointers :Blush2: , I'll email Cwizard as I have it and see if he replies.

Doesn't look like he visits forum any more as it says:-

Last Activity
04-10-2014 09:36 AM

On his profile page.

[jubbly]

Exactly the same as mine. Knock it into neutral next time it's doing it and see if it stops.

Changed the oil and filter in my tiptronic and it didn't help, Apparently it the torque converter not knowing what to do and seems to be more common on these cars than i thought.

Amazingly mine didn't do it on the test drive either.

Thinking about it I can't recall the car doing it at all for a while, will check tomorrow.

[Chriseybaby]

Cheers gup, much appreciated.

it does stop when I knock it into neutral so I have done some coasting to avoid it.

how long has yours done it for jubby?

[jubbly]

A few weeks after I bought it, which is just over two years now, will check it on the way to work today

[jubbly]

Well I did wonder last night about this, as my car used to surge quite violently at times and I couldn't remember the last time I noticed it. Coming to work today it's hardly doing it now, so perhaps the oil and filter change did work, it's just taken a few thousand miles to make a difference.

[Chriseybaby]

Well that sounds positive, especially if its been doing it for 2 years and hasn't blown up. My wallet has just relaxed slightly.

How much did you pay for the gearbox oil and filter? I've had 2 quotes, one was from the Audi specialist in my village who quoted £175 the other was a less local specialist who quoted £391. I have a feeling the £391 sounds like a proper job whereas the cheap one will be a quick drain and top up.

[jubbly]

Did it myself got the parts from tps and gearbox oil from eBay cost around £170 all in

[Chriseybaby]

Not sure I'm brave enough to do it myself but I am friends with a VAG technician (Seat) who could probably do it for a few quid. Seat don't have the 3ltr Tdi so he hasn't ever done it can't be rocket science can it?

[Guest 2]

It's the same idea/principle throughout the VAG group gearboxes anyway. I can't see it being a problem.

[Chriseybaby]

Cheers Chris, does that mean you will need VCDS to do it then?

[jubbly]

VW Audi Forum - The #1 VW Group Community (http://www.vwaudiforum.co.uk/forum/showthread.php/151502-DIY-Tiptonic-Oil-and-Filter-Change-3-2-FSI-Quattro?p=926879#post926879)

Helpful how to guide, part numbers are on post 4, however the gasket was 09L 321 371a as the later cars have less bolts holding the sump on so a different gasket.

[Chriseybaby]

Thanks for your help, do you know what year the gasket number changed?

[jubbly]

Not really, mines a 57 plate so guess yours would be the same

[Guest 2]

Cheers Chris, does that mean you will need VCDS to do it then?

Yes as you need to monitor the temperature of the oil before and after.

An ex-VW guy done mine, no issues bar a mess-up by Bristol Transmissions.

[MarkTM]

Appreciate that when drained the normal way on our tiptronic boxes you'll only get out circa 7.5l and (IIRC) the capacity inc the torque convertor is 10l, so your 'clean' fluid will be diluted as to make it 75% cleaner.

I had mine done in 2013 and didn't really notice it settling until a couple of hundred miles later, that said I had intended to do another fluid (without new filter) change and Bristol Transmissions quoted me £120+VAT just for the fluid change. Pentasin fluid was £9pl and the filter was

The fluid and filter are £156 inc

ZF6HP19 Fluid Filter Change Kit - Bristol Transmissions Ltd (http://www.bristoltransmissions.co.uk/shop/product.php?id_product=25)

Then you'll have to pay a specialist to change, they charged me £320 inc for the job

There is also a bolt tightening sequence once the sump is off that may improve things :)

[Chriseybaby]

Is the bolt tightening sequence documented anywhere?

[Guest 2]

ZF 6HP19A tiptronic gearbox (A6 3.0 TDI Quattro) (http://www.vwaudiforum.co.uk/forum/showthread.php/141671-ZF-6HP19A-tiptronic-gearbox-(A6-3-0-TDI-Quattro)?highlight=Bristol+transmissions)

Any ex VAG mechanic will have their head screwed on and have the workshop manual at their disposal.

[Scott K]

This is a great site I came across a few days ago. Lots of information on zf gearboxes and instructions on changing gearbox oil!
http://www.zf.com/brands/content/en/zf_parts/technology_in_practice_zp/oil_change_procedure_zp/how-to-change-oil.html

[heavy_landing]

Has anyone got to the bottom of this one?
My 57 3.0TDI Allroad hunts sometimes on the over-run, it doesn't do so if you select Neutral and I strongly suspect it's the gearbox 'driving' the engine.
72,000 odd miles, I'm going to get the fluid changed but not hopeful.....

[cozmo]

I'm also curious if anyone has found any "miracle" cure for this. Just got myself an 2007 Allroad 2.7 tdi (with 90k miles on the clock) , and it behaves just like in the video. When letting off the accelerator in moderate speeds - the revs are hunting and unable to "settle" down or stabilize on a particular RPM. It seems to not happen in low speeds around 20 mph. Just ordered the Ross-Tech cable, so will have a go with VCDS when it arrives. Not expecting to find much though...

[jubbly]

Mine is loads better after gearbox oil and filter change.

[Chriseybaby]

Not yet, still waiting to get the gearbox oil done

[cozmo]

Guess I'll try that then. After lots of googling, this seems like a very common problem. Not only on TDIs, but lots of problems with the 3.2 petrol too. So problems seems to be engine independent, but I think both the TDIs and 3.2 FSI uses the same tiptronic gearbox (?).
Also - for many the problem seems to be resolved by replacing the torque converter. I guess that is a engine out operation, and not something to try unless one is 100% sure that is the culprit...

[MarkTM]

Audi say sealed for life, ZF says fluid filter change every 80k miles, since Audi only warranty the gearbox for 80k miles I know who I'l be trusting :D

I didn't have any surging/pulsing issues prior to the change but notice things are a lot smoother even 20k miles after :)

[Guest 2]

mine didn't make any difference and was changed at 100k i think.

[cozmo]

After some hours on google, it seems like the main reason for this surging issue is either the TC, or if one is lucky - the throttle body.
Useful information found here : '05 A6 - Frustrating surge at low rpm, low load - AudiWorld Forums (http://www.audiworld.com/forums/a6-s6-c6-platform-discussion-58/05-a6-frustrating-surge-low-rpm-low-load-2854672/)

I'll start with getting a new throttle body. Replacing the TC seems like lots of work. I'm doing all repairs myself - but the TC job sounds like an engine out thing - and I am not sure if I have the time to do that in the near future.

[MarkTM]

Clean the TB first before replacing, I always look for the cheapest options first and then move up to the more expensive :)

[cozmo]

Good point. Guess it's worth a try, even if it feels like "all others" with same problem have come up short by just cleaning it :D

[54A4Avant]

Hi Cozmo - how did this work out? Did cleaning the TB make any difference? Did you replace it? Is the issue fixed?

[cozmo]

I had the Tb tested, and it was not at fault. Local Audi specialist concluded it had to be a faulty Torque Converter. Sold the car and forgot all about it...

[jubbly]

I had the Tb tested, and it was not at fault. Local Audi specialist concluded it had to be a faulty Torque Converter. Sold the car and forgot all about it...

Sold mine too, torque converter fault most likely though I lived with mine for over 4 years, never got any worse, a little better after oil change on the box.

[cozmo]

Which model year was yours?

[jubbly]

2008. On 57 plate

[cozmo]

Interesting. Mine was 2008 too.
I now have a similar car, but 2009 facelift. All these problems seem to happen to pre-facelift models, but who knows... Knock on wood...

[lynalldiscovery]

For t/c that are on their way out or a little tired I can highly recommend Dr Tranny (2xtubes needed) have used it in my disco for t/c judder quite a known fault on the land rovers.
Its isnt perfect but its a vast improvement, I also changed the gearbox oil a couple of times.

[54A4Avant]

Just wondering if it's possible these issues were throttle body related, as in both cases it seems the assumption was it's TC, but this was never tested with replacement of the TB?

[jubbly]

Replaced my throttle body, made no difference, also as when you put the car into neutral the car behaves with rock solid rpm. Can’t see that being anything other than gearbox.

[cozmo]

Well as I wrote, I had a local Audi specialist test my TB and they found nothing wrong. Since the TB is prone to failure, they do have equipment to test its functionality...

[54A4Avant]

Replaced my throttle body, made no difference, also as when you put the car into neutral the car behaves with rock solid rpm. Can’t see that being anything other than gearbox.

Got it, didn't realise that, thanks.

[cozmo]

What could be interesting to know is if the TC-unit was upgraded or replaced with another unit on the facelift i 2009 - since most problems seems to be on pre-facelift cars...

[54A4Avant]

Well as I wrote, I had a local Audi specialist test my TB and they found nothing wrong. Since the TB is prone to failure, they do have equipment to test its functionality...

Ok I saw that, but testing is one thing, replacing is a better test imho. These components can bench test ok, but still have issues which only show up when installed (e.g. Air leak).

Anyway the the reason I'm asking - I have a 3.2 FSI which just started doing something similar. Cruising at low throttle positions the revs are bouncing up and down and this is shortly after I had the air box out and intake disconnected from the TB, so I'm wondering if I've messed up reinstalling it - perhaps introduced a slight leak at the seal behind the TB while reinstalling the intake hose. I'll test to see if the issue happens with the car in neutral as this is something I've not yet tried.

[cozmo]

I see.
I doubt the problem lies with the TB. Unfortunately, this is probably the TC.......And the only permanent cure is to have it replaced :/

[niedzial1983]

Tc or valves in the tranny. I have same problem and im booked with zf for diagnostics

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