A4 low revs lumpy

[Nik_87]

Hi all,

Just purchased an A4 B9 after previously owning a B8. It’s the 2.0 tdi ultra 147bhp.

During my drive home I noticed at lower revs, (speed not so much a factor but rev range seemed to be) the car seems to be quite lumpy/juddery and doesn’t accelerate that smoothly.

When putting my foot down it feels fine and revs smoothly, but at low revs or even when letting off it’s really not that smooth. Can feel it through the seat so balanced the rear wheels today in case that was the sensation I was feeling as sometimes it can be difficult to decipher an engine judder when the wheels are out of balance.

Not having that much experience with these engines over the last few years is this normal for the A4 or that engine? Does anyone else get that sensation at all at lower revs? Cruise control on earlier today and was as smooth as anything but put the foot down again low revs and get that slightly hesitant feeling.

No diag codes at all, feels slightly like bad fuel so next call will be fuel filter change and a full tank but if this is normal at least it stops starting a diagnostic darts session.

Many thanks
Nick

 

[pelhamsdetailing]

How many miles has it done? It may have quite a bit of carbon build up within the intake system, which could be causing your hesitation. No matter how much the engine wants that air, if it's bunged up in there like it's got the flu, then air wont be getting through there any time quick, resulting in a lack of "go" or smoothness.

 

[Nik_87]

How many miles has it done? It may have quite a bit of carbon build up within the intake system, which could be causing your hesitation. No matter how much the engine wants that air, if it's bunged up in there like it's got the flu, then air wont be getting through there any time quick, resulting in a lack of "go" or smoothness.

It’s on 90k. Fuel and Air is certainly part of the checks I’ll be doing when trying to diagnose, at least inspecting and cleaning what I can get to along with a fresh, genuine filters.

I’m guessing by the lack of results when I search, this may not be common, having found lots of rough idle/gear stick vibration threads but nothing I can find that exactly replicates my issue.

Thanks for the input and suggestion buddy

 

[pelhamsdetailing]

90k is plenty of time for the EGR and air intake to make good friends with each other. Outside of eyeing over live data of various sensors, you could try disconnecting the MAF. I've read that if it doesn't make any difference, then the MAF may be at fault. It'll throw a fault code in doing this, which can be cleared via software once plugged in.