2009 B8 A4 2.0T Stutter and Hesitation During Heavy Acceleration

[Rated Tortoise]

Hey guys, yesterday about an hour into a 4 hour drive the engine started shuddering when accelerating in 5th gear. At first it was only in 5th, but I was able to duplicate the issue in 3rd and 4th as well with RPM above 3k. It idles normally, accelerates just fine as long as it's gentle, but really struggles with 5th especially. It feels like a misfire, but is not kicking any codes or CEL. Another way to describe the feeling is the jolt when missing a gear when riding a bike, but happens randomly and not on every cycle.

The car has about 87k, and has been well-maintained. Right now Im thinking about throwing ignition coils at it, but not sure where else to look.

TIA!

[rcprato]

When was your last intake carbon cleaning?

[Rated Tortoise]

When was your last intake carbon cleaning?

Around 30k ago. Could that be the cause? Or is it symptomatic of something else?

[adamleaf8601]

This is almost certainly a pin hole in the PCV valve. I had the exact same issue.

[Rated Tortoise]

Good to know. Ill have to look into that. I ended up replacing the spark plugs and ignition coils, and it seems to have fixed the problem. I now have full power all the way through acceleration and all hesitation and stutter has disappeared. Ill look into the PCV if the issue recurs though! Thanks for the inputs.

[Walletclan]

Get a GFB DV+

[audi-root]

HPFP


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[flowhigh]

It's a good time to replace all the ignition coils.

[tangj2]

My 2011 B8 has recently developed this symptom, feels like a misfire under acceleration 2500rpm to 5000rpm, replaced spark plug and coils a few months ago as well as DV+. And there is no CEL or codes from VCDS reading. No engine code no transmission code. Carbon clean was done 30000miles ago. Is that mean I have a bad HPFP?

[audi-root]

My 2011 B8 has recently developed this symptom, feels like a misfire under acceleration 2500rpm to 5000rpm, replaced spark plug and coils a few months ago as well as DV+. And there is no CEL or codes from VCDS reading. No engine code no transmission code. Carbon clean was done 30000miles ago. Is that mean I have a bad HPFP?

Did you figure it out?


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[jelan]

So I'm having a similar issue with my 2011 A4 B8. The stuttering occurs during fast acceleration above 2k RPMs. If I increase speed slowly, I can get up to 3k RPMs with no issues. No codes or engine lights (even flashing). My mechanic says that coils or spark plugs would give consistent sputtering so I'm thinking HPFP or PCV Valve. Some additional information, I was a victim of the timing chain tensioner issue. Had to replace timing chain, tensioner, water pump and overhaul the cylinder head with new valves. The stuttering started after the major repair so I'm thinking something is loose when the car got put back together.