hesitation at high RPM

[PetrolDave]

Wouldn't the coil packs have forced the car into 'safe mode'?

Not always - if the fault only persists for a few seconds and then goes away for a while it will get logged as intermittent and it won't go into limp mode.

[tartan_rob]

You can log plug voltages throught he rev range and see what they do. It would only take 1 or a sticky injector to cause such issues.

[almeister09]

Been talking to dealers today, Software 090 is cold start issues,there is common issues on these engines with the vaves coking up hence high revs after software version 090. Blah blah, This is not my concern though,all coil packs when scoped on r/t are all good.

[George1976]

Unless you're the Master Tech at Derby Audi this is spooky. My 06 plate has had, and STILL has this exact same issue for 4 months, and has been at the dealers about 8 times. They have now had it for 2 weeks, and the latest decision as of today is... wait for it.... NEW ENGINE!!

They did all the ECU updates, I PAID for new plugs, they've checked every possible sensor and still no solution found. This main issue is that no fault code is generated, so there's lots of head scratching.

The techs at Derby have been very good, and persistent with HQ to get it resolved. As the hesitation can sometimes be quite subtle, you may get the car back several times with them thinking it's cured. Last week they had an endoscope in the cylinders taking pictures, as they believed that oil was passing the rings via excessive scoring.. not the case. However extended measurements have uncovered that it is running a bit rich... and the cure is to swap the block?!?! I doubt it.

I'm fully expecting them to discover that the injectors are badly coked up (as were the SPs) despite the car only doing motorway mileage... and that being the problem. Difficulty is they won't swap all the injectors first as it's cost prohibitive...!

The engine swap will be done in 2 weeks... I'll keep you posted. All I can say is that I have a horrible feeling ours won't be the last one's to develop this problem.

All I can explain the sensation as is like this... you put your foot down (100% throttle) in 4th or 5th and anywhere between 5k and 6k rpm it's like there's a strong gust of wind which hampers your progress, which goes away as the revs exceed 6500. It feels very much like a single cylinder misfire, fuel starvation or driving a bmw...

[PetrolDave]

I think I might just stick with SW 0080, and live with the poor cold running for the first mile or so...

[George1976]

This problem is in no way related to the ECU software. It had the 0080 version when it developed the fault. Judging by the state of the plugs when they were changed, I'd say the 0090 upgrade is absolutely essential. You would not believe the difference with the new "clean" plugs.

[PetrolDave]

So what is almeister09 on about then???

[George1976]

Sorry Dave, I've lost the thread (excuse the pun).. it sounds as if almeister has exactly the same issue as mine, to which so far no resolution has been found. I was simply saying that it's not the ECU software causing our problem, but nevertheless I'd recommend the 0090 upgrade to avoid the coking issue judging by the dreadful state of my plugs.

[PetrolDave]

it sounds as if almeister has exactly the same issue as mine

I can't understand his post ... I'm amazed you can draw that inference from it.

[George1976]

it sounds as if almeister has exactly the same issue as mine

I can't understand his post ... I'm amazed you can draw that inference from it.

..It was the title that gave me the clue.. " hesitation at high RPM" .. it's exactly how I would summarise my issue, and there are no other threads on here pertaining to similar symptoms.

[NGS521]

How many miles have the cars that have this problem done?

[George1976]

How many miles have the cars that have this problem done?

37k. 85% Motorway.

[pippyrips]

interesting reading on the issues with valves & injectors can be found here:

http://www.bobistheoilguy.com/forums/ub ... er=1171236

[bn8959]

Hi,

I had my RS4 updated to 0080 a few weeks ago and since then Ive noticed a significent decrease in performance. I had a chance to give it a bit of a blast yesterday and I definately noticed hesitation at high RPM too. It seemed to happen at about 4500 to 5000 rpm and 6000 to 6500 rpm, you can feel your head 'nod' forward due to lower acceleration as the revs sweep up through those rev ranges. Although it definately wasnt a stutter and didnt last 2 to 4 seconds, like previously mentioned, so is likely to be a different issue. However it must be linked with the ECU update, as it started straight after the upgrade.

My car is currently in for DRC issues and Ive asked them to investigate this too - not sure what they'll come up with - but I'd really like to get my old performance back!

[PetrolDave]

I had my RS4 updated to 0080 a few weeks ago and since then Ive noticed a significent decrease in performance. I had a chance to give it a bit of a blast yesterday and I definately noticed hesitation at high RPM too. It seemed to happen at about 4500 to 5000 rpm and 6000 to 6500 rpm, you can feel your head 'nod' forward due to lower acceleration as the revs sweep up through those rev ranges. Although it definately wasnt a stutter and didnt last 2 to 4 seconds, like previously mentioned, so is likely to be a different issue. However it must be linked with the ECU update, as it started straight after the upgrade.

Mine behaved like that after the 0080 upgrade (I described it on here as "I drove an RS4 to the dealer and drove an S4 home").

Turned out that the dealer hadn't cleared all the basic settings (learned values) that the previous 0050 software had accumulated. It seems that 0080 has different meanings for these values so if the old 0050 values are left you get less performance and "strange" effects.

The cures are either to take it back to a dealer who knows what they're doing and get the basic values reset; or "drive it like you stole it" (which overrides the stored values).