How smooth is your engine at idle?
03-24-2016, 10:45 PM
#12
AudiWorld Senior Member
I haven't noticed this as an issue, but some additional details might help. Is this when the engine is cold or is it warmed up already? What RPM is your car idling at? Do you see the RPM jumping up and down when this happens? I adjusted the idle RPM on my previous S4 to smooth out the idle, and I think with newer models it can be adjusted using VAGCOM.
03-25-2016, 03:26 PM
#13
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I have only noticed this at cold start... idle is at 1.8K-ish
smooth for 20-30 seconds - Minor tremor - smooth for 10-15 secs - minor tremor.
I will try it for longer and see.
smooth for 20-30 seconds - Minor tremor - smooth for 10-15 secs - minor tremor.
I will try it for longer and see.
03-26-2016, 04:39 AM
#14
AudiWorld Senior Member
I don't think what you're describing is unusual for a cold start (not sure how cold your ambient temps are). Cars run rich when the engine is cold, and the ECU is basically guesstimating while everything (like the oxygen sensor) gets up to operating temp.
03-26-2016, 12:08 PM
#16
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The intermittent and slight vibration at idle rpm (regardless of park, drive, etc.) is my biggest pet peeve with my SQ5. Mine seems to be more prevelant when warm, and I have to have the radio (bass) down and my left arm on the door armrest and/or right on the center console armrest to notice it. I can't feel it through the steering wheel.
This is apparently normal for the 3.0T in the S models (stiffer engine mounts?). Lots of people report small amount of idle vibration with the S4 based on numerous searches I've done. 90-degree V-6's are notoriously difficult to balance they say. The dealership also called mine normal when brought to their attention, but that's no surprise or definitive answer there.
Some report it going away with an intake/filter change and in rare cases new plugs. A slight increase in idle rpm definitely gets rid of it though.
This is apparently normal for the 3.0T in the S models (stiffer engine mounts?). Lots of people report small amount of idle vibration with the S4 based on numerous searches I've done. 90-degree V-6's are notoriously difficult to balance they say. The dealership also called mine normal when brought to their attention, but that's no surprise or definitive answer there.
Some report it going away with an intake/filter change and in rare cases new plugs. A slight increase in idle rpm definitely gets rid of it though.
03-27-2016, 07:35 AM
#17
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Correction: I can feel it through the seat, and it was present during a cold, wet start today. It really just depends on exactly where my idle is based on cold/warm start, IAT, pressure/density, etc... I'm confident a 100 rpm raise on the idle speed would get rid of it for good.
