S3/2.0TFSI Weird Revving Problem
A couple of weeks ago on one journey I noticed this problem but it disappeared on the next drive and I forgot all about it. Today my car has been into Audi for a four wheel alignment and as usual I took the Bluefin off before I took it over.
So they finished with the car and I took it away with no problems but had a stop-off on my way home. I took the chance to reload the Bluefin while I was there and now the problem has reared its head again and it's a lot more prominent.
A picture paints a thousand words so I took a video of it:
There are no gear changes involved there by the way and it doesn't matter what gear I'm in. It normally happens somewhere in the 3-5k RPM area although I don't think it's exclusive.
I'm assuming that since I have reloaded the map its been highlighted massively by the map learning mode and there's a bit more fuel being pumped in than usual. It certainly feels like a fuel problem, as if too much fuel is being injected, it's not being burned off fully so the ECU is then holding back on fuel delivery.
Has anyone experienced this before? Or got an idea what it may be?
Unfortunately I don't have my VCDS cable with me this weekend to check anything but can anyone suggest something for me to check/measure specifically which would be of use?
Blimey, thats an odd co-incidence...
So here goes with a bit of a post, sorry its long, but it should be helpful...
I also had an irregular hard to recreate problem occurring with an 07 S3 for a couple of months. The problem was most pronounced when 'booting' the car (or 'giving it welly', 'making progress' - which ever you prefer).
The scenario is not easily repeatable or quantifiable as it did not seem to be triggered or related to vehicle engine speed at the time, i.e. it did not always occur at 3500 to 4000 rpm in a specific conditions.
The issue was observed as follows,
- With the engine at say 3000 rpm in 4th.
- Push accelerator to the floor - Normally the Engine revs pick up rapidly from 3000 to 3800
- Engine revs will pick up but not related to the throttle position (pedal still pushed to the floor).
- Engine revs pick up and suddenly peak from 3000 to 4100 then remain for a while (3-4 seconds) before decreasing (pedal still pushed to the floor).
- At the same time the vehicle speed remains constant and then very slowly picks up speed (as you would expect) after the peak in revs has reduced.
- No ESP or any other warning lights are ever shown on the dashboard.
- There is no feeling of ESP being engaged, noticeable clutch slip, nor is 4WD power distribution being felt.
- There were no diagnostics logged in the ECU (checked a couple of times by Audi) indicating the fault is mechanical, as no electronic diagnostics were reported.
Additional details to reproduce the issue.
- Firmly place foot on the accelerator pedal to the floor, allow speed to build, at some point the revs will increases suddenly without any additional increase in vehicle speed for a couple of seconds.
- It was also possible to take your foot the accelerator pedal and then back onto the accelerator pedal to the floor and re-observer the same sudden increase in revs without any corresponding increase in vehicle speed (for a couple of seconds).
- Once the increase in revs has occurred the situation returns to normal and placing the foot back on the accelerator pedal to the floor observes the normal expected linear increase in speed with corresponding revs.
The problem could occur,
- In many conditions and does not appear to be related to the road surface (i.e. snow or ice).
- During dry days, wet days, nights, mornings, evenings, in straight lines, going around corners, up hills, down hills, etc.
The issue did not seem to be related to temperature of the engine or other variables,
- The car is never ever booted when cold, water is always at 90 and engine oil up to 80 (approx) before 'booting'.
- Until at temp the car is driven under 4000 rpm in all gears.
- The car is 'booted' fairly regularly, once warm, but never enough to engage ESP.
- ESP is always enabled by default in the car and never deactivated.
The issue was
- Not very noticeable at high speeds, above 70 MPH.
- Not noticeable at very low speeds, below 30 MPH.
- Happening after changing gears or booting it in gear.
- Increasingly noticeable when accelerating up to 70 MPH, with foot to the floor.
- Best reproduced with prolonged periods of sustained speeds (50 MPH roadworks) then accelerating up to 70MPH with full throttle whilst leaving.
- Not very apparent at very low revs, i.e. initially pulling away from lights, but did occur after pulling away whilst 'making progress' moving through the gears, when in higher gears 3rd, 4th, 5th for instance.
So what was found?
- After removing the gearbox normally a clutch would leave a powder residue of metal deposits as the surface wore away, in this case the powder was sticky indicating a very fine leak or mist which was sticking the powder together. Its not been confirmed this was the issue, but so far the fault has not re-appeared. I do not know if a leak was found on the part replaced.
What was replaced (under warranty)?
- A complete clutch assembly
- The Hydraulic line and dampener
- The intercooler Interchange Condenser (as at the time the chap noticed this had a fine mist on it indicating a leak (- but could not be related to the issue, but is responsible in the cars power delivery)
Its a bit worrying that you have exactly the same symptoms on a similar age car, mine is now 2 1/2 years old with around 25000 miles on it. You do not mention the age of the car in question which would be useful to know.