car accelerates on it's own when cold

Hey all, I have some very interesting symptoms i'd like to share.

Whenever I do a cold start and the rpms hover around 1500rpm, my car does this weird acceleration on it's on. So I get in my car in the mornings, start the car, let it idle for about 30s to a 1 min depending on how cold it is, then I drive off... normally the rpm is around 1400-1500 by the time I start moving. Then as I drive, in 2nd gear, or 3rd, or 4th, if I let off the gas, the car still accelerates on it's on...but it's not like it's giving gas, it just keeps pulling at a constant rate and the rpms continue to rise of course, when normally it should start to slow down, especially if it's in gear. Also, if I let the car pull forward at this constant acceleration, and I eventually press the clutch to stop the pulling, I hear this whistling/whirling/whooshing noise, kind of like a tdi when you switch gears that doesn't have a muffler, or a a turbo car that has a blowoff valve...

This only happens when the engine is cold, when it has warmed up and the rpm stabilizes to normal idle, it doesn't happen

Thoughts?

Secondary air pump. Its normal.

The engine behaves differently under fast idle conditions, but if you're trickling along in gear with the throttle closed I would expect it to increase revs not significantly higher than it does when you're sitting still out of gear..


...if it creaks, it's probably made by VAG

yup, very normal. Although for me it's usually closer to 1250rpm. It helps me not to stall it in the morning when my hand-eye coordination isn't quite there yet. I've used this to accelerate up to 35mph without touching the throttle before . Also, I am pretty sure the noise is turbo surge caused by the diverter valve not activating. I like it because there's no other time I get to hear my turbo make that noise.

Huh, never would've thought, I've never experienced anything like this in my previous cars but good to know it's not broken and a normal occurrence