BackNBlack

I've just purchased a 2010 S4 with 13K miles on it. The car runs extremely well, but the idle seems a bit rough. It's idling around 600-700, and you can feel the reverberation through the seats. Any thoughts? The car seems extremely well maintained and has never been in an accident.

Thank you,


Paul

rktskicar

do you have access to a VAG (VCDS)? If you do, check for codes. Many times rough idle is from random misfire.

Bruce

Construct

How rough is rough? I can 'feel' my car idle through the seats too, but between the low idle RPM and what I assume are pretty aggressive cam profiles, this seems normal to me - this isn't a Lexus.

If you're hearing/feeling syncopated or irregular vibrations though, I'd agree w/ rktskicar on the misfire, and probably suspect the ignition coils - two of my previous VW/Audi cars have been in for coilpack recalls (although I never actually experienced misfires in those cars) . . .

BackNBlack

Thanks for the quick responses. I don't have a VAG tool, and the car does not seem to be misfiring. The idle is steady and rhythmic, just evident. I'm coming from a '05 S4, and the V8 was basically asleep at idle. I've only driven two B8s including this one, so I wanted to ensure this was "normal".

-Paul
P.S. And yes thankfully it is not a Lexus.

NABS4

I notice that the idle is slightly rough as well. The tach doesn't move around, but I do notice it. I have checked error codes with the VAG com, but I have never had any show up. It's a feature, not a problem.

vanja026

I have the same "issue". Took the car to two different dealers and both said everything is normal....

terminal nonchalance

This is a pretty standard feeling in a performance oriented vehicle. As long as ther is no shaking of th entire car at idle I'd say all is normal. I am guessing that the S4 has stiffer engine and tranny mounts which will transmit more of the mechanical vibration. This is a good thing. My m3, b6 S4 and even my gti all exhibited this to a certain extent. You really want to feel some idle sit in a 60's big block chevelle or nova with solid motor mounts and a lumpy cam... Now that is some fun shakin'.

BackNBlack

Thanks everyone for the feedback. I'm glad I'm not the only one. That's reassuring it is "normal", because I absolutely love the car. It is a rocket compared to my V-8.

benoa

Same here : rough, in the sense that I notice it a lot more than on my 3.2 B8 but not as rough as the S5 though. Anyway, nothing dramatic.

riegerman

The exterior or interior of the IS-F may not be to your liking but the new 2011 IS-F outperforms the M3. Lexus has got it's **** together for the 2011 ISF performance wise.