Hesitation problem...........

[Gavc500]

The beast is in Audi right now with a hesitation/come shudder or wobble through the car between 1500-2000 revs. In for fault diagnosis.

Under full WOT is still quick enough, but doesn't feel totally linear, its as though there is a slight sensation of almost being very linear in power, but not quite.

Apart from that the hesitation is there every time I drive it but more pronounced when hot and more when locking in 3rd gear at 1800 revs, in fact the rev counter oscillates about 100-150 revs whilst holding a steady speed and you can feel the engine increase/decrease as it does so.

Its worse under load up a hill at a steady 30 mph, only do this speed on one hill and past one gatso, so its the same every night driving home.

Audi's initial thought after hooking up the diagnostics is yes its there, but no fault codes thrown..... and I thought it may be air mass meters. The initial recommendation is to change the plugs (as they are 40k miles old)and air filter, but that seems a bit of a guess.

Any ideas?

[graybags]

The Service book recommends plugs every 20k so it would definitely be worth doing.

Good luck, Gray

[Gavc500]

Yes I checked my service book and saw plugs need to be changed very 20k, not sure they have been though.

[markademus]

Hi all,
Im new to all this and wanted to say that my Audi is suffering with very similar simtoms. I have changed the plugs and still it has made no difference. I would like to know what the problem is to get it sorted.

[Rilla]

Due to my experiences with previous cars, i would stake my claim on the mass air flow sensor, i have had similar effects in my old merc and it was that, know several other ppl who have had same thing in diff cars aswell. Like the others said tho, worth doing the plugs/filters if they r that old.

[Gavc500]

Audi recommended new plugs and air filter which was a sensible option, did that and it seems to have gone, maybe still a very slight feeling...... which if it is I would bet its the MAF!

Anyhow, if I feel any of it again, even slightly, then new maf's are goin in.

[el_ringo]

I had something similar to those symptoms a while ago and it turned out to be a fault with one of the injectors. The wire had worn but the fault was picked up by my VagCOM.

[GregRS6]

dav

I would be very careful running the car with the MAF's down.(if they are fookt!)
Apparently the gearbox detects signal's from the MAF's. non functioning MAF's can lead to failure of the awful Audi RS6 Gearbox.
I speak from experience!!
I am sure this is right!
Specialist garage's are very keen to change the MAF's every year if possible when a service is due.
Better to b safe than sorry!

Greg

[Rilla]

Yeah i go with what greg said, worth doing regularly. I did get told by a merc tech that MAF's are the sort of part that work at 100% for a day, then slowly start to die from that point, he also recommended changing them every 12-18 months.

[MoRS6+]

..MAF's are the sort of part that work at 100% for a day, then slowly start to die from that point.

Funny that.. that is exactly how I would describe the DRC system!