6MT Idle Question

**af1** · 01-24-2016 05:21 AM

For those with the 6MT trans anyone notice an unexplained jump in rpm's while idling?
Frequently while sitting at a light say clutch in, foot on brake 1st gear the rpm's will increase from the normal 600-700 rpm to 1100-1200 rpm and then go back down. At first I thought I was accidentally depressing accelerator. Not the case. I've tried shutting off climate control thinking it was possibly A/C compressor turning off and on. No change. It does seem however that it will not do this if I idle in neutral with clutch out and foot on brake. Any ideas would be appreciated.

**af1** · 01-24-2016 05:24 AM

Forgot to mention completely stock 2016 with 8000 miles.

**boostx2** · 01-24-2016 05:31 AM

Wonder if it's the anti-stall hall effect switch in the clutch master cylinder giving a false positive. Does the car consistently do the rpm bump while letting out the clutch in 1st gear (as it should)?

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**af1** · 01-24-2016 05:45 AM

Can't say for sure about rpm bump while letting out clutch in 1st gear. I'm usually working throttle while letting clutch out in 1st gear to get moving. Sorry for confusion?

**sebgreen** · 01-24-2016 07:31 AM

Could be any electrical draw that makes the engine idle increase.

How long is the increase for?

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**MrFunk** · 01-24-2016 07:38 AM

Yes - normal.
It's the anti stall function. Happens in some instances where the car will intervene and add a bit of throttle when unnecessary.

**S4Drew** · 01-24-2016 08:03 AM

As others have said, the car has an anti-stall feature; if you let the clutch out in 1st gear from an idle, the car will apply light gas to prevent you from stalling. My guess is this is what you are feeling, so either you are letting the clutch out a little bit while you are sitting, or the sensor is way too sensitive.

I would say if you're going to sit idle somewhere for longer than a few seconds, drop into Neutral and let the clutch out. If you are consistently sitting with your foot on the clutch, you will wear it out early.

**MrFunk** · 01-24-2016 08:12 AM

Originally Posted by S4Drew

I would say if you're going to sit idle somewhere for longer than a few seconds, drop into Neutral and let the clutch out. If you are consistently sitting with your foot on the clutch, you will wear it out early.

This is good advise... this is how I was taught to drive MT and I've taught a couple new drivers myself and always tell them to do this.

**Sailingtime** · 01-24-2016 08:32 AM

Originally Posted by af1

For those with the 6MT trans anyone notice an unexplained jump in rpm's while idling?
Frequently while sitting at a light say clutch in, foot on brake 1st gear the rpm's will increase from the normal 600-700 rpm to 1100-1200 rpm and then go back down. At first I thought I was accidentally depressing accelerator. Not the case. I've tried shutting off climate control thinking it was possibly A/C compressor turning off and on. No change. It does seem however that it will not do this if I idle in neutral with clutch out and foot on brake. Any ideas would be appreciated.

I guess it's normal, I have been to dealer few times with this issues. My car idles extremely uneven in neutral no clutch or brake pedal applied. Audi told me nothing to worry about, it's normal. My engine will hunt 150-250rpm for no apparent reason. It runs great otherwise.

**af1** · 01-24-2016 08:47 AM

Thanks for the feedback.
I've been driving manuals of various makes and models for 40 years and the only anti-stall feature I was aware of was the driver. This is a new one on me. I guess it makes sense now. As I stated originally it doesn't seem to happen when I let it idle in neutral and clutch out.

**iviegatron** · 01-24-2016 01:34 PM

As others have mentioned, it's normal. Below is a video I recorded when it was happening to me.

**sebgreen** · 01-24-2016 03:09 PM

Originally Posted by iviegatron

As others have mentioned, it's normal. Below is a video I recorded when it was happening to me.

Your indicator sounds odd in that clip.

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**MrFunk** · 01-24-2016 04:20 PM

Originally Posted by sebgreen

Your indicator sounds odd in that clip.

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Sounds normal to me...

**Dr GP** · 01-24-2016 06:42 PM

I don't think there is anything actually wrong .

**SouthernBoy** · 01-25-2016 05:06 AM

Never noticed this with my 2016 S4. But then, I don't sit at a light waiting for it to change with my foot on the clutch and the transmission in first gear. Not the best thing to do for the release bearing. When I am waiting for a light, my foot is off of the clutch and the transmission is in neutral. Tach displays a steady 700 RPM.