Woo Woo Woo Woo Woo - B7 S4 Surging Idle on cold startup

B6/7 S4/RS4
#14

Just bringing this up to the top. I was told when I first got my car to always let the revs drop to 800 before driving it, so I would usually let the car idle for a good minute or so. And I would always have an intermittent CEL almost weekly for random misfires, which would pop up shortly after I started driving the car. I could not for the life of me track it down.

As soon as I saw this post I started just turning the car on and driving away. Haven’t seen a CEL, scanned for codes and nothing! Since I normally would have seen a CEL at least twice by now, I’m assuming this was my fix ;D

#15

could be but who knows. Hopefully.

#16

Chances are it did fix the issue. Cold starts are the moat dangerous time for a motor. Your Audi guide even says don’t let your car sit for more then 3seconds before you drive the car. The count is spot on as usual.

Cold start missfires are normal depending on you plugs heat range

#17

I fully appreciate that we should start and not sit idling for many minutes. But what about us in snowy/icey climes? Often I get frozen fluid on the inside of the car and I need some heat to help get rid of it. Any advice? The manual just says to make sure visibility is satisfactory before moving off. That can be several minutes for me.

#18

Good question. Weather is pretty cold here too, I’ve often had to sit for a couple minutes warming up.

#19

Throw the wifes car out of the garage and park yours in there! ;D

#20

Since you seem to have this car thing ;D, why not use your wife’s car as
a) it will be warmer as it’s already in the garage and
b) will stop you getting frozen fluid on the inside of your car!! :smiley: :smiley:

#21

Lol this is almost eerie now, I’m starting to think my check engine light is broken. It’s so unfamiliar to not see it for such a long time :stuck_out_tongue:

#22

Wow I did not know it was harmful to wait for the RPMs to drop to 800. My car has been woo woo wooing away and i was starting to get paranoid because once every month or 2 I get a maf code. So I was begining to think I had an electrical or vacuum issue.
Any other S/C guys have the woo woo on start ups?
For my car it’s worse if I start the car with the AC on but it smooths out after 10-30 seconds

#23

yeah, cold idling sucks for the car. Just get in and drive it (responsibly and conservatively till it warms up)

#24

Wow I did not know it was harmful to wait for the RPMs to drop to 800. My car has been woo woo wooing away and i was starting to get paranoid because once every month or 2 I get a maf code. So I was begining to think I had an electrical or vacuum issue.
Any other S/C guys have the woo woo on start ups?
For my car it’s worse if I start the car with the AC on but it smooths out after 10-30 seconds

#25

My car does it too.

Sometimes it is worse than others and the exhaust makes it more obvious. Like when I start the car up to get it off the lift after sitting for a few days.

#26

yeah, cold idling sucks for the car. Just get in and drive it (responsibly and conservatively till it warms up)

#27

the exhaust makes it embarrassing lol. Sounds like shit when it happens.

Some say it’s throttle body alignment related, but I’m almost 100% suer it’s secondary air injection. The RS4 has a slightly different version. It doesn’t bounce like that, it just revs at a high 1700 RPM idle when cold, and also secondary air injection increases volume like crazy and is super load when cold. Goes away in like 1 minute.

Many guys in Europe elect to have their secondary air injection disabled. I had a tune from JHM once when I was helping Count Vohn with B7 S4 launch control development, and it eliminated the woo woo . I loved it.

#28

My car does it too.

Sometimes it is worse than others and the exhaust makes it more obvious. Like when I start the car up to get it off the lift after sitting for a few days.

#29

I have to post this…woo woo

https://www.youtube.com/watch?v=n2fWCSMfqC0

#30

That shit is funny euro.
I’m just glad I can stop searching for an error that does not exist.
I just feel bad for my neighbor, since I have headers that are catless And a non resonated FI x pipe. Not really… Lol

On another note my inside driver side door handle just lost its function. No I have to roll the window down.
If it’s not one thing it’s another. I always have shit luck with my cars. Lol

#31

the exhaust makes it embarrassing lol. Sounds like shit when it happens.

Some say it’s throttle body alignment related, but I’m almost 100% suer it’s secondary air injection. The RS4 has a slightly different version. It doesn’t bounce like that, it just revs at a high 1700 RPM idle when cold, and also secondary air injection increases volume like crazy and is super load when cold. Goes away in like 1 minute.

Many guys in Europe elect to have their secondary air injection disabled. I had a tune from JHM once when I was helping Count Vohn with B7 S4 launch control development, and it eliminated the woo woo . I loved it.

#32

I have to post this…woo woo

https://www.youtube.com/watch?v=n2fWCSMfqC0

#33

That shit is funny euro.
I’m just glad I can stop searching for an error that does not exist.
I just feel bad for my neighbor, since I have headers that are catless And a non resonated FI x pipe. Not really… Lol

On another note my inside driver side door handle just lost its function. No I have to roll the window down.
If it’s not one thing it’s another. I always have shit luck with my cars. Lol