Getting a slight miss/stumble/hiccup at idle, any ideas?

[drewgold]

I have noticed lately that at idle, usually more so when the car is warm, I get a slight miss or hiccup. It's very subtle, but can feel it through the steering wheel, shifter and even the seat. It's just a really quick blip, not even enough for the tach needle to dip.

It's intermittent, and will usually happen a few times while say stopped at a light. There are no misses under hard acceleration or cruising.

Some forum posts I have read say that this is normal and it's just the computer adjusting the fuel mapping? I have never noticed it before though which worries me a bit.
Any ideas? It's not bad now but want to be on top of it in case it's a sign of a developing problem.

[jimrobbington]

How many miles? Could be carbon build up maybe.

[drewgold]

How many miles? Could be carbon build up maybe.

155,000kms/96,313miles
Not likely to be carbon buildup as the cylinder head/valves are almost new.
I guess it could be carbon on the injectors though, had a shop inspect the injectors with a camera and they said the tips look fine (no fuel dripping with engine off, no excessive carbon on them) and seem to hold pressure well.

[jimrobbington]

Could be actually up in the intake flaps. I have a rough start issue and hiccup kinda action, but only when the engine is cold due to a malfunction with the flaps. I did a carbon clean but never thought to look up in the manifold the other way. I replaced the motor, but that didn't fix it. Guessing there is carbon up in the manifold blocking the flaps from their full range of motion.

[drewgold]

Could be actually up in the intake flaps. I have a rough start issue and hiccup kinda action, but only when the engine is cold due to a malfunction with the flaps. I did a carbon clean but never thought to look up in the manifold the other way. I replaced the motor, but that didn't fix it. Guessing there is carbon up in the manifold blocking the flaps from their full range of motion.

That's a good call! I didn't think about the flaps. I'll take a look. I also have had the motor replaced but to my knowledge, the flaps haven't been touched.

[Alamento]

My b7 has been doing that for the past 275,000 km. lol.

I get a couple of misfires when I'm stopped at a light after an hour on the highway. It happens almost daily. Like you you described, you can feel it through the whole car.

I worried about it 275,000kms ago. Not so much anymore. Still running strong.

[audimeister]

Coilpacks and plugs?

[BenMTL]

Coilpacks and plugs?

If they haven't been replaced recently, I definitely do that + N80....Always smooths out the idle.

[drewgold]

If they haven't been replaced recently, I definitely do that + N80....Always smooths out the idle.

I have already put in new plugs and coils. Thought for sure new coils would help but no luck.

Haven't done the N80. I hate to throw parts at a problem but the N80 is pretty cheap so may give it a try.

I worried about it 275,000kms ago. Not so much anymore. Still running strong.

That's actually good to hear, it's really not a big deal but have been concerned that it's a sign of another lurking problem. May just be one of those many Audi quirks!